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Digital technologies/3D printing/3D printing- Intermediate

2023-08-28T22:20:44Z

Cecilial:

This page will focus on intermediate 3D printing skills. You should be familiar with [[Digital technologies/3D printing/3D printing- Beginner|3D Printing- Beginner]] before continuing.

==[[Digital technologies/3D printing/3D printing- Intermediate/Types of printers|Types of printers]]==

===Printers===
{{#lsth:Digital technologies/3D printing/3D printing- Beginner|Which 3D printers do we have?}}
There are many different types of 3D printers that exist. Theses printers can be primarily categorized into 7 categories:

# Material Extrusion
# Vat Polymerization
# Powder Bed Fusion
# Material Jetting
# Binder Jetting
# Directed Energy Deposition
# Sheet Lamination

[[File:Material Extrusion .png|thumb|Material Extrusion ]]
Material extrusion is the most commonly used 3D printing method. It refers to 3D printing where the material is extruded through a nozzle on to a build plate in a pre-determined path and the material solidifies into a solid object. Typically, the material used are plastic such as PLA and ABS. It is usually the most cost-effective 3D printing option, however, it does not provide the best dimensional accuracy. The material properties of printed object is also not that great compared to other methods. The FDM printers in Makerspace are a good example of material extrusion 3D printing.
[[File:Vat Polymerization .png|thumb|Vat Polymerization ]]
[[File:Powder Bed Fusion.png|thumb|Powder Bed Fusion]]
Vat polymerization also known as resin 3D printing uses a light source to selective cure photopolymer resin in a vat. The build plate is moved vertically once the first layer of the print is cured. This is done layer by layer until the entire object is built. After the printing process, the object is cleaned of the remaining liquid resin and cured to ensure the mechanical properties of the part. The most common form of vat polymerization is stereolithography (SLA).

SLA is the oldest form of 3D printing technology. SLA printers use mirrors known as galvanometers with one on the X-axis and one on the Y-axis. The galvanometers aim the laser beams across a vat of resin, curing and solidifying a cross-section of the object inside the building area. Resin 3D printing allows for smoother surface finish with finer feature details. Makerspace offers resin 3D printing through Elegoo printers.
[[File:Material Jetting.png|thumb|Material Jetting]]
Other forms of resin printing include digital light processing (DLP) and liquid crystal display (LCD). DLP 3D printing uses a digital light projector instead of a laser beam like SLA printers. The digital projector screen flashes an image of a layer across the platform. This cures all points simultaneously. LED screens or a UV source is used to project light onto the resin. This light is directed to the build surface by a digital micromirror device (DMD). LCD 3D printing is also called masked stereolithography (MSLA) is similar to DLP above. Instead of a DMD, LCD printers uses an LCD screen. LCD is a newer technology designed to be an affordable alternative to DLP and stereolithography. It cures an entire layer of resin at once using an array of ultraviolet LED as a light source. It uses an LCD to selective mask UV light so that only selected areas are cured.
[[File:Binder Jetting.png|thumb|Binder Jetting ]]
[[File:Directed Energy Deposition.png|thumb|Directed Energy Deposition ]]
Powder bed fusion printers spread a thin layer of powdered material over a print bed which is melted (typically by a laser). This process is repeated with the powder layer fusing at specific points with the previous layer until the object is completed. The final product is encased and supported in unfused powder. This method is great for parts with complex geometries however it has a higher machine cost with higher material cost. It often results in slower build rates.

Material jetting involves tiny droplets of material that are deposited onto the build plate. The droplets are cured when exposed to light. This process is repeated layer by layer. This process allows for different materials to be printed in the same object. It can create textured surface finish. However, the process has limited materials and often have weaker mechanical properties with a higher process cost.

Binder jetting uses a liquid bonding agent that selectively binds layers of powder together. The printer nozzle will pass over the print bed and selective deposit droplets of binding agent on the powder layer. This process combines powder bed fusion and material jetting.
[[File:Sheet Lamination .png|thumb|Sheet Lamination ]]
Directed energy deposition is a process where material is fed and fused at the same time as it is deposited. This is typically only performed on metal material. It is very similar to welding. This process is often used to repair or add features to metal objects by printing on pre-existing metal objects.

Sheet lamination is technically considered a form of 3D printing. However, it differs significantly from the other methods mentioned above. It stacks and laminates sheets of very thin material together to produce a 3D object. The stack can also be cut mechanically or by lasers to create the final shape. There are many ways fuse the material layers such as heat and sound. Since material is fused together then cut, this way of 3D printing generates much more waste than other technology.

Each brand of printer will have a different slicer and way of starting the prints which is explained in the following sections.

===Slicers===
There are many different slicers that can be used. Typically each 3D printer company will have its own 3D slicer software. For example, within Makerspace Ultimaker Cura is the typical slicer used for the Ultimaker printers. Other slicer software used within the Makerspace includes MakerBot Desktop for the MakerBot replicator, Dremel Idea Builder for Dremel printer and Eiger for Markforged printer.

MakerBot Desktop is used for the MakerBot Replicator printers in Makerspace. Since the MakerBot replicators are discontinued printers so the slicer software is no longer updated. To used the MakerBot Desktop to print follow the steps below:

# Open MakerBot Desktop.
# Click add a file.
# Select the printer. Ensure the correct printer is selected. In Makerspace we have the Replicator 2 printers. Click on “Device” on the top menu. Then “Select type of device”, where Replicator 2 would be selected.
# Send the file to the printer. There are two ways to do so, using a SD card or a USB cable.
#* SD Card: Click on “Export print file”. Replicator printers will only work with '''2GB''' SD cards (or smaller). SD cards with a greater storage capacity will give you an “SD card read error”.
#* USB Cable: Connect the printer with your computer using a USB cable. A printer should show up at the bottom of your MakerBot Desktop screen. Click “Print”. Once the “Print” has be clicked, the compute cannot be unplugged from the printer.

Eiger is the slicer used for the Markforged printers in the space. Eiger is a web-based slicer software. You will need to be invited into the Makerspace organization and make an account with Eiger. Once you have logged in, follow the steps below to slice your print.

# Click on the Import a File icon and import your STL model file.
# Open the part file.
# Adjust the print settings to your desired options.
# Once you are ready to print, click on “Build View”.
# Select “Mark Two” as the printer.
# Click on “Print”.

Dremel = Dremel Idea Builder

#Load your .stl file by clicking the load button on the menu on the left hand side. You can modify your object (scale, move, or rotate) using the buttons on the left hand side
#Click build.
#Select your settings and your method of printing. Either using an SD card or a USB cable.
#*SD card: You are saving the machine to an SD card and moving the SD card to the printer
#*USB cable: You are using a USB wire to transfer the fire to the printer. What is nice with the Dremels is the file is downloaded to the machine. Therefore you can unplug the wire when the file has transferred.

===Start the print===
Starting your print is very simple. Simply save your file to an SD card or connect your computer to the printer and click print or build.

'''Dremel'''

If you are using a USB cord, the print with start automatically when you hit build in on your computer. Follow the following step if you are using the SD card.

#Place your SD card in the SD card slot in the 3D printing. This is found on the right hand side near the front of the printer.
#If the 3D printer is not already on, turn on the printer using the on/off switch located at the right hand side near the back of the printer.
#Using the front screen, press build ->The picture of an SD card ->select your file -> Build.

==[[Digital technologies/3D printing/3D printing- Intermediate/Custom Slicer Settings|Custom Slicer Settings as an Intermediate User]]==
In the beginner section of 3D printing, basic slicer settings such as layer height, infill percentage, supports and adhesion have<s>s</s> been introduced. In this section, more advanced settings such as print speed, nozzle size, adhesion type (…etc) will be discussed.

In order to start customizing your slicer settings, you will have to access the setting menu. To do so, make sure you are in the prepare view. Click on the dropdown triangle in the top right hand corner. You will be shown the recommended settings automatically. Then select the custom button at the bottom to further customize your options.

<youtube>gHUxuMe-plYc</youtube>

===How to Modify Parameters===

===Layer Height===
Layer heights are generally changed to increase printing speed. A larger layer height means a faster print as the printer can print less layers to achieve the final height. However, increasing layer height will decrease the resolution and quality of the print. Therefore, increasing layer height should only be done on larger prints without fine details. It is recommended to keep the layer height between 25%-75% of the nozzle diameter and a 50% nozzle diameter is generally what is used as the layer height. If the layer height is too low, it can result in the plastic being pushed back into the nozzle creating a blockage. If the layer height is too high, it can be difficult for the layers to stick to each other.

Within the 3D printing community, there are discussions of “the magic number”. This refers to the increments of layer heights that provides the most efficient prints. It considers the mechanical properties of the printer stepper motors. It takes the ‘steps’ that the stepper motor travel in as layer height intervals. So the layer heights are set as multiples of these ‘steps’. In the case of the Ultimaker printers, the magic number is 0.04mm.

====Walls ====
There are many things that can be customized within the wall settings. Cura also allows the user to customize wall line count which is the number of passes the nozzle will perform for the walls. Changing this value will automatically change the value for wall thickness. However, users can change the value manually as well. Typical values for wall thickness are chosen depending on the purpose of the print and the material used. Generally the default values of 0.8mm-1.6mm (3-4 wall lines) should be sufficient for typical prints. The wall thickness should be set at multiples of nozzle size for ideal printing. If the strength of the part is crucial, use larger values for wall thickness such as 2-3mm. If the model has fine details where strength is not required, wall thickness can be reduced to 0.4mm. The user can also customize horizontal expansion value. This setting is used to compensate for the horizontal shrinkage of the print. It will add the input value to either side of the XY plane. This option is typically enabled when printing material that will shrink when cooled and dimensional accuracy is required. It is unnecessary for PLA printing.

====Top/Bottom====
Top and bottom layers are the layers at the top and bottom of the 3D model. In Cura, top and bottom thickness can be adjusted and customized. Similarly to wall thickness, this can be adjusted by the number of layers or by the thickness value. The thicker the layers are the stronger the model would be. The thicker the layers are will also increase the watertightness of the model. However, this means that the model will use more material and take a longer time to print. It is usually recommended that the Top/Bottom Layer Thickness should be at least 1-1.2mm thick, ensure that it is a multiple of the layer height which will prevent print defects.

====Infill====
In the previous section, the recommended infill percentage was discussed. In this section, infill pattern can also be customized. There are 14 different patterns to choose from.

<youtube>e6es3gT15HA</youtube>

Lightning, lines, zig-zag are best used to print models and figurines with a typical 0-15% infill. This is because they don’t require the prints to have a high strength as they are not subjected to rough handling or put under stress. The three patterns result in the fastest prints. Grid, triangles and tri-hexagon are used for typical 3D prints with infill density for 15-50%. It is suitable for prints with low stress. Choosing these patterns may increase print time by up to 25% when compared to lines. If the print is functional such as a shelf bracket that requires strength in multiple directions, cubic, cubic subdivision, quarter cubic, octet and gyroid are great options. Many times these patterns are also chosen for infill densities smaller than 50% for their aesthetics. Concentric, cross and cross 3D are often chosen for flexible filament prints.

====Print Speed====
The basic print speed settings control the speed of all stages of the printing process. However, the speed of each stage can be further customized in the advanced settings. This includes infill speed, wall speed, travel speed etc. The ways in which the print speed will affect the final print are not always obvious. If the print speed is set too fast, the printer might not be able to dispense enough material through its nozzle per unit of time to fill the desired volume with the required amount of material. This can lead to bad adhesion between layers or even a complete lack of adhesion to layers. Therefore, it is important to consider the ratio between layer height and layer speed. The Ultimaker 2+ in Makerspace are capable of achieving speeds of up to 300mm/s. However, this is not recommended as it significantly reduces the quality of the print. Realistically it is possible to print reliably using about 70-80mm/s depending on the material and the model.

The ways in which the print speed will affect the final print are not always obvious. If the print speed is too high, the printer might not be able to dispense enough material through its nozzle per unit of time to fill the desired volume with the required amount of material. This can lead to bad adhesion between layers or even a complete lack of adhesion to layers. The ratio of layer height to layer speed (i.e.: material outflow through the nozzle) should therefore always be considered when FDM printing (the exact subject though being more of an intermediate subject). When making parts that will bear loads, print speeds are increasingly important as layer adhesion becomes an important factor in the strength of the final part, so much so that parts may be annealed (uniformly re-heated through a controlled process) to obtain better properties across layers.<ref>Agnieszka Szust, Grzegorz Adamski, ''Using thermal annealing and salt remelting to increase tensile properties of 3D FDM prints'', Engineering Failure Analysis, Volume 132, 2022, 105932, ISSN 1350-6307, <nowiki>https://doi.org/10.1016/j.engfailanal.2021.105932</nowiki>.</ref>

==== Travel====
Retraction is enabled when the printer has to travel between two printed parts. Without retraction, the extruded material will hang between the parts. Enabling retraction prevents the “stringing” of the extruded material which will result in a cleaner model. Enabling Z-hop when retracted will move the build plate down by the set value when retraction is performed. This will prevent the nozzle from hitting the object or damaging the print surface. However, adding additional nozzle travel will increase the print time.

====Cooling====
[[File:Supports.png|thumb|378x378px]]
The fans allow the material to cool properly before the next layer is printed. By enabling the fans, it will allow layers with short layer time and those with bridges/overhangs to have a better print quality. Fan speed can be adjusted based on the needs of the print. A higher print speed means better cooling and reduces the oozing of the material.

====Supports====
Supports were introduced in the beginner module of 3D printing. In this section, further details of support will be explained. Typically supports are used when there is an overhang in the design. There are two options when implementing supports, support structures need to touch the build platform or touch the top of the model. The default settings have the supports touching the build plate only. However, this can be changed to have supports touching everywhere. This can be useful as it increases the support area but it can be extremely difficult to remove supports that are on the printed objects. The support overhang angle can also be changed. Generally, supports are printed for overhang greater than 60 degrees. If the object is printed at a slow speed, the overhang angle might need to be lowered than if printing at a higher speed. Your design can also be altered to reduce supports. Filet and chamfer sharp angles which will reduce overhang angles and increase the quality of the print. You can also consider splitting your print into multiple parts to be assembled afterwards.

====Adhesion====
[[File:Adhesion.png|left|thumb|413x413px|(left to right) skirt, brim, and raft]]
There are three types of adhesion, skirt, brim and raft. Brim adds a single layer flat area around the base of the print model which prevents warping. This is the default adhesion type. The brim is connected to the model making the bottom surface area bigger. It not only increases the adhesion of the model to the build plate, but it also prevents the corners of the model from curling. Materials with high potential for shrinking such as ABS will benefit from a brim. Models with a large base or a thin bottom should also use a brim adhesion. As raft adhesion adds a thick grid with a roof between the model and the build plate. This is typically used when the bottom surface of a model is not completely flat or has little area to adhere to the build plate. A skirt is a line printed around the model on the first layer. It is typically not used to help the print adhere but used to prime the nozzle and check for bed leveling.

==[[Digital technologies/3D printing/3D printing- Intermediate/Dual Extrusion|Dual Colour and Dual Extrusion]]==
Dual colour prints refer to a technique that can print multiple colour<ins>s</ins> on one model using one nozzle head. This is achieved by switching the filament during the printing process. Dual extrusion refers to printing a model with 2 nozzle<ins>s</ins> to extrude two different filament<ins>s</ins>. This will allow for mixing colours, gradients, or patterns. It can also print models using two different material<ins>s</ins> for different parts of the object for complex geometries that would otherwise be difficult to achieve.

<youtube>QRroBtNXDvc</youtube>

Dual colour prints are achievable using the Ultimaker 2+ printers. In order to change the colour during the print, a script is added to the g-code telling the printer to stop the print at a certain instance. This is done during the slicing process in Cura.

#Click on “Extensions” in the top menu bar.
#Select “Post-processing” -> “Modify g-code”.
#Click on “Add a script”
#Select “Pause at height”

At this point, there will be many different settings to modify. First, determine if you would like to pause at a height value (mm) or at a layer number. Choosing a layer number would be a simpler option in ensuring that the print ends when a full layer is completed. The layer number can be seen in the “Preview” mode on Cura. The model can then be sliced like normal. Once the print stops, the material can be changed (ask the staff) to complete the print in a different colour<ins>.</ins>

Dual extrusion prints are possible using the Ultimaker 3 or Raise printer<s>s</s> in Maker<ins>s</ins><s>S</s>pace. To do so with the Ultimaker, two separate 3D models are needed. If they are part of the same model, they will be merged together in Cura. Ensure that the printer selected is Ultimaker 3. The printer can be added using “Add printer” button. Open both models in Cura and set the print core and the materials. This can be done through the printing options beside the printer selection. Both print cores should be set at '''AA .4.''' The material is set to PLA by default but it can be changed to the material of our choice. There is no need to change the colour of the filament on Cura as it will be determined by the filament that is loaded in the printers. By default, both model<ins>s</ins> will be set to print with core 1. To change the print core, select the model then select per model settings and print model with print core 2. After the print core, merge the two models together. Select both model<ins>s</ins> by holding shift while left clicking on both parts. Both models should the<ins>n</ins><s>m</s> be highlighted in blue. Then, right click and select “Merge Models”. The two models will then become a single model. At which point, you can adjust the printer settings like a regular single extrusion print. If you would like to customize the settings for one print core, the printer settings need to be assigned in custom model. 
==[[Digital technologies/3D printing/3D printing- Intermediate/Print Orientation|Print Orientation]]==
<youtube>OqRbSkX5IJk</youtube>

Print orientation is crucial to the success of the 3D model print. It heavily influences the speed and quality of the result. There are many different factors to consider when choosing how to orient your print.

Understand the build volume of the printer. The print needs to be oriented in a way that it will physically fit in the printer when printed. If the print is too big, the model can be divided into multiple parts to be printed separately. The Ultimaker 2+ printers have a build volume of 223 x 223 x 205mm.

To determine which face of your design should face down on the build plate, it is important to choose the best face for stability and bed adhesion. This is typically a face that is large enough to provide stability and a flat surface to minimize the need for build plate adhesion.

It is also important to consider the mechanical stresses that your part will experience. Orient the part so that the direction of minimum applied stress is along the build direction (vertical). The build direction is typically weaker since it relies on the bond strength between layers rather than the strength of the material. The print should also be oriented to minimize print time and supports used. These two factors are connected as the more supports needed, the longer the print will be. 

==[[Digital technologies/3D printing/3D printing- Intermediate/Post-Processing 3D prints|Post-Processing 3D prints]]==
 There are a number of post processing possibilities with 3D printed models. The options available are dependent on the material used. In this section, post-processing possibilities for PLA that are available in the Makerspace will be explored. The video below will explain the basics of post-processing. Everything used in the video is available at the finishing station in the Makerspace.
==[[Digital technologies/3D printing/3D printing- Intermediate/Print Orientation|Print Orientation]]==

<youtube>l6dI3RDorwk</youtube>
<youtube>ZTE9bJyUO_8</youtube>

The most basic post-processing procedure is support removal. The Ultimaker 2+ printers in Makerspace are single extruder printers which means the supports are printed using the same material as the main model. Typically, the supports are easily removed by breaking them off the printed model. However, when supports are placed in tight corners or hard to reach places, additional tools such as pliers will be needed to remove the material. Dual extruder printers will allow you to print the supports with a different soluble material than the main part. This means the difficult to remove supports can be dissolved away by soaking it in another liquid.

Another basic procedure is sanding. 3D printed parts will often have rough surfaces from the layers. Sanding is the easiest way to create a smooth surface. At the finishing station, there are sandpaper of different grit sizes to sand down your model. There are also files at the station for edges and holes. It is important to sand the surfaces in circular motions to ensure the aesthetics of the model.

Gluing the model is one of the most common post-processing options to attach parts together. There are many glue options available at the Makerspace, including super glue and hot glue. Hot glue is easy to use but it will leave a visible gap as 2-3mm of glue is needed to secure the parts together. Hot glue is also not very strong. Super glue is a good option for a seamless seal that cures fast.

Painting is one of the most common finishing processes. The model needs to be primed first before being painted. The model should be sanded with a low and then medium grit sandpaper. Prime the model with a coat of primer paint. Once everything is dry, you can start painting your model with other colors. Acrylic paint and paintbrushes are available to use at Makerspace.

==[[Digital technologies/3D printing/3D printing- Intermediate/Bed Levelling, Filament Change|Bed Levelling, Filament Change]]==

===Bed Levelling===
<youtube>0shirFB7o1s</youtube>

If the printer is not printing properly (especially if the issue is noticeable on the very first layers of the print, where a difference in the layer height is noticeable), the build plate level may need to be adjusted. For minor adjustments, this can be done by using the three knobs (thumb screws) on the underside of the plate. For more major adjustments (>1mm), the build plate should be leveled through the printer’s onboard software by going to Maintenance→Build Plate, and following the onscreen instructions. If unsure, always use the latter method. The calibration cards needed are at the finishing station. However, in Makerspace, bed levelling should only be performed by the staff.

===Filament Change===
<youtube>9v1w_dmpLu0</youtube>

To change the filament on an Ultimaker 2+ printer, go to Material→Change in the printer’s user interface and follow the onscreen instructions. If ever the filament has almost run out, or if you desire to change the color of a print midway, you may navigate to Pause→Change Material and following the onscreen instructions. If changing mid-way, it is recommended that the older filament be completely purged from the nozzle using the new filament. Otherwise, the result will not be good. Again, within the Makerspace, this should only be done by the staff working.

==[[Digital technologies/3D printing/3D printing- Intermediate/Selecting Nozzle Sizes|Selecting Nozzle Sizes]]==
[[File:Nozzle Size.png|thumb]]
Nozzle size is the first decision to make when 3D printing. Within Makerspace, there are four options of nozzle size using the Ultimaker 2+, 0.25mm, 0.4mm, 0.6mm, and 0.8mm. Choosing between the options depends on the fine details of the model and the print speed required.

*A smaller nozzle size will allow for finer details and better dimension accuracy. However, it will also take longer to print the model.
*A larger nozzle can provide faster print time and also create stronger prints.
*A smaller nozzle diameter can cause it to be more difficult to print with overhangs as each layer has less width to adhere to the next one.
*However, with a smaller nozzle, the supports are easier to remove as the printer will use less material for supports making it easier to break away.
*A larger nozzle is able to print with less infill as the walls would be thicker to ensure strength.

==Troubleshooting==

<nowiki>https://www.youtube.com/watch?v=R-CMotQ-nqI&t=249s</nowiki>
{| class="wikitable"
|'''Issue (symptom)'''
|'''Possible Cause (diagnosis)'''
|'''Potential Fix (cure)'''
|-
|Warping
|Not enough/too much model base surface contact to the print bed
|Add build plate adhesion such as a brim or a raft. Refer to adhesion section for further explanation.
|-
| rowspan="3" |Bad adhesion
|Dirty build plate
|Clean off the build plate first. Debris and oils from your fingers can cause difficulties for the material to stick.
|-
|Not enough/too much model base surface contact to the print bed
|Add build plate adhesion such as a brim or a raft.
|-
|Uneven print bed/Bed too far from nozzle at initial layer
|This is the least likely possibility. Relevel the build plate. Ask a Makerspace staff for more details.
|-
| rowspan="2" |No extrusion
|No filament
|Replace filament spool. Ask a Makerspace staff to replace the filament spool.
|-
|Filament clog
|Keep in mind that it is uncommon that this is the actual cause of lack of extrusion. Ask a Makerspace employee to assist with further diagnosis.
|-
| rowspan="3" |Underextrusion
|The forwarding mechanism (gearbox) ground through the filament
|Move the filament out of the forwarding mechanism. Use the change material feature to speed up the removal. While the mechanism is whirring to remove the material, pull slightly on the filament, at the back of the printer for the mechanism to grab. Break the filament clean off at the section where the filament was ground, clean up the end by cutting it off. Re-forward the material into the printer, making sure the right material is chosen in the menu.
|-
|Wet (very brittle) filament
|Remove wet section of the filament (0.25 to 0.5m length) and re-load. Ask a Makerspace staff for further support.
|-
|Filament clog
|Keep in mind that it is uncommon that this is the actual cause of lack of extrusion. Ask a Makerspace employee to assist with further diagnosis.
|-
|Print not level
|Model not well seated on bed (in slicer)
|Use the snap to bed feature in your slicer (when available), add a brim to preview which flat sections are well seated on the bed
|-
|Drooling
|No supports when needed
|Add supports. Refer to the supports section.
|}

==References==
<references />

Digital technologies/3D printing/3D printing- Intermediate

2023-08-28T22:15:55Z

Cecilial:

This page will focus on intermediate 3D printing skills. You should be familiar with [[Digital technologies/3D printing/3D printing- Beginner|3D Printing- Beginner]] before continuing.

==[[Digital technologies/3D printing/3D printing- Intermediate/Types of printers|Types of printers]]==

===Printers===
{{#lsth:Digital technologies/3D printing/3D printing- Beginner|Which 3D printers do we have?}}
There are many different types of 3D printers that exist. Theses printers can be primarily categorized into 7 categories:

# Material Extrusion
# Vat Polymerization
# Powder Bed Fusion
# Material Jetting
# Binder Jetting
# Directed Energy Deposition
# Sheet Lamination

[[File:Material Extrusion .png|thumb|Material Extrusion ]]
Material extrusion is the most commonly used 3D printing method. It refers to 3D printing where the material is extruded through a nozzle on to a build plate in a pre-determined path and the material solidifies into a solid object. Typically, the material used are plastic such as PLA and ABS. It is usually the most cost-effective 3D printing option, however, it does not provide the best dimensional accuracy. The material properties of printed object is also not that great compared to other methods. The FDM printers in Makerspace are a good example of material extrusion 3D printing.
[[File:Vat Polymerization .png|thumb|Vat Polymerization ]]
[[File:Powder Bed Fusion.png|thumb|Powder Bed Fusion]]
Vat polymerization also known as resin 3D printing uses a light source to selective cure photopolymer resin in a vat. The build plate is moved vertically once the first layer of the print is cured. This is done layer by layer until the entire object is built. After the printing process, the object is cleaned of the remaining liquid resin and cured to ensure the mechanical properties of the part. The most common form of vat polymerization is stereolithography (SLA).

SLA is the oldest form of 3D printing technology. SLA printers use mirrors known as galvanometers with one on the X-axis and one on the Y-axis. The galvanometers aim the laser beams across a vat of resin, curing and solidifying a cross-section of the object inside the building area. Resin 3D printing allows for smoother surface finish with finer feature details. Makerspace offers resin 3D printing through Elegoo printers.
[[File:Material Jetting.png|thumb|Material Jetting]]
Other forms of resin printing include digital light processing (DLP) and liquid crystal display (LCD). DLP 3D printing uses a digital light projector instead of a laser beam like SLA printers. The digital projector screen flashes an image of a layer across the platform. This cures all points simultaneously. LED screens or a UV source is used to project light onto the resin. This light is directed to the build surface by a digital micromirror device (DMD). LCD 3D printing is also called masked stereolithography (MSLA) is similar to DLP above. Instead of a DMD, LCD printers uses an LCD screen. LCD is a newer technology designed to be an affordable alternative to DLP and stereolithography. It cures an entire layer of resin at once using an array of ultraviolet LED as a light source. It uses an LCD to selective mask UV light so that only selected areas are cured.
[[File:Binder Jetting.png|thumb|Binder Jetting ]]
[[File:Directed Energy Deposition.png|thumb|Directed Energy Deposition ]]
Powder bed fusion printers spread a thin layer of powdered material over a print bed which is melted (typically by a laser). This process is repeated with the powder layer fusing at specific points with the previous layer until the object is completed. The final product is encased and supported in unfused powder. This method is great for parts with complex geometries however it has a higher machine cost with higher material cost. It often results in slower build rates.

Material jetting involves tiny droplets of material that are deposited onto the build plate. The droplets are cured when exposed to light. This process is repeated layer by layer. This process allows for different materials to be printed in the same object. It can create textured surface finish. However, the process has limited materials and often have weaker mechanical properties with a higher process cost.

Binder jetting uses a liquid bonding agent that selectively binds layers of powder together. The printer nozzle will pass over the print bed and selective deposit droplets of binding agent on the powder layer. This process combines powder bed fusion and material jetting.
[[File:Sheet Lamination .png|thumb|Sheet Lamination ]]
Directed energy deposition is a process where material is fed and fused at the same time as it is deposited. This is typically only performed on metal material. It is very similar to welding. This process is often used to repair or add features to metal objects by printing on pre-existing metal objects.

Sheet lamination is technically considered a form of 3D printing. However, it differs significantly from the other methods mentioned above. It stacks and laminates sheets of very thin material together to produce a 3D object. The stack can also be cut mechanically or by lasers to create the final shape. There are many ways fuse the material layers such as heat and sound. Since material is fused together then cut, this way of 3D printing generates much more waste than other technology.

Each brand of printer will have a different slicer and way of starting the prints which is explained in the following sections.

===Slicers===
There are many different slicers that can be used. Typically each 3D printer company will have its own 3D slicer software. For example, within Makerspace Ultimaker Cura is the typical slicer used for the Ultimaker printers. Other slicer software used within the Makerspace includes MakerBot Desktop for the MakerBot replicator, Dremel Idea Builder for Dremel printer and Eiger for Markforged printer.

MakerBot Desktop is used for the MakerBot Replicator printers in Makerspace. Since the MakerBot replicators are discontinued printers so the slicer software is no longer updated. To used the MakerBot Desktop to print follow the steps below:

# Open MakerBot Desktop.
# Click add a file.
# Select the printer. Ensure the correct printer is selected. In Makerspace we have the Replicator 2 printers. Click on “Device” on the top menu. Then “Select type of device”, where Replicator 2 would be selected.
# Send the file to the printer. There are two ways to do so, using a SD card or a USB cable.
#* SD Card: Click on “Export print file”. Replicator printers will only work with '''2GB''' SD cards (or smaller). SD cards with a greater storage capacity will give you an “SD card read error”.
#* USB Cable: Connect the printer with your computer using a USB cable. A printer should show up at the bottom of your MakerBot Desktop screen. Click “Print”. Once the “Print” has be clicked, the compute cannot be unplugged from the printer.

Eiger is the slicer used for the Markforged printers in the space. Eiger is a web-based slicer software. You will need to be invited into the Makerspace organization and make an account with Eiger. Once you have logged in, follow the steps below to slice your print.

# Click on the Import a File icon and import your STL model file.
# Open the part file.
# Adjust the print settings to your desired options.
# Once you are ready to print, click on “Build View”.
# Select “Mark Two” as the printer.
# Click on “Print”.

Dremel = Dremel Idea Builder

#Load your .stl file by clicking the load button on the menu on the left hand side. You can modify your object (scale, move, or rotate) using the buttons on the left hand side
#Click build.
#Select your settings and your method of printing. Either using an SD card or a USB cable.
#*SD card: You are saving the machine to an SD card and moving the SD card to the printer
#*USB cable: You are using a USB wire to transfer the fire to the printer. What is nice with the Dremels is the file is downloaded to the machine. Therefore you can unplug the wire when the file has transferred.

===Start the print===
Starting your print is very simple. Simply save your file to an SD card or connect your computer to the printer and click print or build.

'''Dremel'''

If you are using a USB cord, the print with start automatically when you hit build in on your computer. Follow the following step if you are using the SD card.

#Place your SD card in the SD card slot in the 3D printing. This is found on the right hand side near the front of the printer.
#If the 3D printer is not already on, turn on the printer using the on/off switch located at the right hand side near the back of the printer.
#Using the front screen, press build ->The picture of an SD card ->select your file -> Build.

==[[Digital technologies/3D printing/3D printing- Intermediate/Custom Slicer Settings|Custom Slicer Settings as an Intermediate User]]==
In the beginner section of 3D printing, basic slicer settings such as layer height, infill percentage, supports and adhesion have<s>s</s> been introduced. In this section, more advanced settings such as print speed, nozzle size, adhesion type (…etc) will be discussed.

In order to start customizing your slicer settings, you will have to access the setting menu. To do so, make sure you are in the prepare view. Click on the dropdown triangle in the top right hand corner. You will be shown the recommended settings automatically. Then select the custom button at the bottom to further customize your options.

https://www.youtube.com/watch?v=gHUxuMe-plY

===How to Modify Parameters===

===Layer Height===
Layer heights are generally changed to increase printing speed. A larger layer height means a faster print as the printer can print less layers to achieve the final height. However, increasing layer height will decrease the resolution and quality of the print. Therefore, increasing layer height should only be done on larger prints without fine details. It is recommended to keep the layer height between 25%-75% of the nozzle diameter and a 50% nozzle diameter is generally what is used as the layer height. If the layer height is too low, it can result in the plastic being pushed back into the nozzle creating a blockage. If the layer height is too high, it can be difficult for the layers to stick to each other.

Within the 3D printing community, there are discussions of “the magic number”. This refers to the increments of layer heights that provides the most efficient prints. It considers the mechanical properties of the printer stepper motors. It takes the ‘steps’ that the stepper motor travel in as layer height intervals. So the layer heights are set as multiples of these ‘steps’. In the case of the Ultimaker printers, the magic number is 0.04mm.

====Walls ====
There are many things that can be customized within the wall settings. Cura also allows the user to customize wall line count which is the number of passes the nozzle will perform for the walls. Changing this value will automatically change the value for wall thickness. However, users can change the value manually as well. Typical values for wall thickness are chosen depending on the purpose of the print and the material used. Generally the default values of 0.8mm-1.6mm (3-4 wall lines) should be sufficient for typical prints. The wall thickness should be set at multiples of nozzle size for ideal printing. If the strength of the part is crucial, use larger values for wall thickness such as 2-3mm. If the model has fine details where strength is not required, wall thickness can be reduced to 0.4mm. The user can also customize horizontal expansion value. This setting is used to compensate for the horizontal shrinkage of the print. It will add the input value to either side of the XY plane. This option is typically enabled when printing material that will shrink when cooled and dimensional accuracy is required. It is unnecessary for PLA printing.

====Top/Bottom====
Top and bottom layers are the layers at the top and bottom of the 3D model. In Cura, top and bottom thickness can be adjusted and customized. Similarly to wall thickness, this can be adjusted by the number of layers or by the thickness value. The thicker the layers are the stronger the model would be. The thicker the layers are will also increase the watertightness of the model. However, this means that the model will use more material and take a longer time to print. It is usually recommended that the Top/Bottom Layer Thickness should be at least 1-1.2mm thick, ensure that it is a multiple of the layer height which will prevent print defects.

====Infill====
In the previous section, the recommended infill percentage was discussed. In this section, infill pattern can also be customized. There are 14 different patterns to choose from.

<nowiki>https://www.youtube.com/watch?v=e6es3gT15HA</nowiki>

Lightning, lines, zig-zag are best used to print models and figurines with a typical 0-15% infill. This is because they don’t require the prints to have a high strength as they are not subjected to rough handling or put under stress. The three patterns result in the fastest prints. Grid, triangles and tri-hexagon are used for typical 3D prints with infill density for 15-50%. It is suitable for prints with low stress. Choosing these patterns may increase print time by up to 25% when compared to lines. If the print is functional such as a shelf bracket that requires strength in multiple directions, cubic, cubic subdivision, quarter cubic, octet and gyroid are great options. Many times these patterns are also chosen for infill densities smaller than 50% for their aesthetics. Concentric, cross and cross 3D are often chosen for flexible filament prints.

====Print Speed====
The basic print speed settings control the speed of all stages of the printing process. However, the speed of each stage can be further customized in the advanced settings. This includes infill speed, wall speed, travel speed etc. The ways in which the print speed will affect the final print are not always obvious. If the print speed is set too fast, the printer might not be able to dispense enough material through its nozzle per unit of time to fill the desired volume with the required amount of material. This can lead to bad adhesion between layers or even a complete lack of adhesion to layers. Therefore, it is important to consider the ratio between layer height and layer speed. The Ultimaker 2+ in Makerspace are capable of achieving speeds of up to 300mm/s. However, this is not recommended as it significantly reduces the quality of the print. Realistically it is possible to print reliably using about 70-80mm/s depending on the material and the model.

The ways in which the print speed will affect the final print are not always obvious. If the print speed is too high, the printer might not be able to dispense enough material through its nozzle per unit of time to fill the desired volume with the required amount of material. This can lead to bad adhesion between layers or even a complete lack of adhesion to layers. The ratio of layer height to layer speed (i.e.: material outflow through the nozzle) should therefore always be considered when FDM printing (the exact subject though being more of an intermediate subject). When making parts that will bear loads, print speeds are increasingly important as layer adhesion becomes an important factor in the strength of the final part, so much so that parts may be annealed (uniformly re-heated through a controlled process) to obtain better properties across layers.<ref>Agnieszka Szust, Grzegorz Adamski, ''Using thermal annealing and salt remelting to increase tensile properties of 3D FDM prints'', Engineering Failure Analysis, Volume 132, 2022, 105932, ISSN 1350-6307, <nowiki>https://doi.org/10.1016/j.engfailanal.2021.105932</nowiki>.</ref>

==== Travel====
Retraction is enabled when the printer has to travel between two printed parts. Without retraction, the extruded material will hang between the parts. Enabling retraction prevents the “stringing” of the extruded material which will result in a cleaner model. Enabling Z-hop when retracted will move the build plate down by the set value when retraction is performed. This will prevent the nozzle from hitting the object or damaging the print surface. However, adding additional nozzle travel will increase the print time.

====Cooling====
[[File:Supports.png|thumb|378x378px]]
The fans allow the material to cool properly before the next layer is printed. By enabling the fans, it will allow layers with short layer time and those with bridges/overhangs to have a better print quality. Fan speed can be adjusted based on the needs of the print. A higher print speed means better cooling and reduces the oozing of the material.

====Supports====
Supports were introduced in the beginner module of 3D printing. In this section, further details of support will be explained. Typically supports are used when there is an overhang in the design. There are two options when implementing supports, support structures need to touch the build platform or touch the top of the model. The default settings have the supports touching the build plate only. However, this can be changed to have supports touching everywhere. This can be useful as it increases the support area but it can be extremely difficult to remove supports that are on the printed objects. The support overhang angle can also be changed. Generally, supports are printed for overhang greater than 60 degrees. If the object is printed at a slow speed, the overhang angle might need to be lowered than if printing at a higher speed. Your design can also be altered to reduce supports. Filet and chamfer sharp angles which will reduce overhang angles and increase the quality of the print. You can also consider splitting your print into multiple parts to be assembled afterwards.

====Adhesion====
[[File:Adhesion.png|left|thumb|413x413px|(left to right) skirt, brim, and raft]]
There are three types of adhesion, skirt, brim and raft. Brim adds a single layer flat area around the base of the print model which prevents warping. This is the default adhesion type. The brim is connected to the model making the bottom surface area bigger. It not only increases the adhesion of the model to the build plate, but it also prevents the corners of the model from curling. Materials with high potential for shrinking such as ABS will benefit from a brim. Models with a large base or a thin bottom should also use a brim adhesion. As raft adhesion adds a thick grid with a roof between the model and the build plate. This is typically used when the bottom surface of a model is not completely flat or has little area to adhere to the build plate. A skirt is a line printed around the model on the first layer. It is typically not used to help the print adhere but used to prime the nozzle and check for bed leveling.

==[[Digital technologies/3D printing/3D printing- Intermediate/Dual Extrusion|Dual Colour and Dual Extrusion]]==
Dual colour prints refer to a technique that can print multiple colour<ins>s</ins> on one model using one nozzle head. This is achieved by switching the filament during the printing process. Dual extrusion refers to printing a model with 2 nozzle<ins>s</ins> to extrude two different filament<ins>s</ins>. This will allow for mixing colours, gradients, or patterns. It can also print models using two different material<ins>s</ins> for different parts of the object for complex geometries that would otherwise be difficult to achieve.

<youtube>QRroBtNXDvc</youtube>

Dual colour prints are achievable using the Ultimaker 2+ printers. In order to change the colour during the print, a script is added to the g-code telling the printer to stop the print at a certain instance. This is done during the slicing process in Cura.

#Click on “Extensions” in the top menu bar.
#Select “Post-processing” -> “Modify g-code”.
#Click on “Add a script”
#Select “Pause at height”

At this point, there will be many different settings to modify. First, determine if you would like to pause at a height value (mm) or at a layer number. Choosing a layer number would be a simpler option in ensuring that the print ends when a full layer is completed. The layer number can be seen in the “Preview” mode on Cura. The model can then be sliced like normal. Once the print stops, the material can be changed (ask the staff) to complete the print in a different colour<ins>.</ins>

Dual extrusion prints are possible using the Ultimaker 3 or Raise printer<s>s</s> in Maker<ins>s</ins><s>S</s>pace. To do so with the Ultimaker, two separate 3D models are needed. If they are part of the same model, they will be merged together in Cura. Ensure that the printer selected is Ultimaker 3. The printer can be added using “Add printer” button. Open both models in Cura and set the print core and the materials. This can be done through the printing options beside the printer selection. Both print cores should be set at '''AA .4.''' The material is set to PLA by default but it can be changed to the material of our choice. There is no need to change the colour of the filament on Cura as it will be determined by the filament that is loaded in the printers. By default, both model<ins>s</ins> will be set to print with core 1. To change the print core, select the model then select per model settings and print model with print core 2. After the print core, merge the two models together. Select both model<ins>s</ins> by holding shift while left clicking on both parts. Both models should the<ins>n</ins><s>m</s> be highlighted in blue. Then, right click and select “Merge Models”. The two models will then become a single model. At which point, you can adjust the printer settings like a regular single extrusion print. If you would like to customize the settings for one print core, the printer settings need to be assigned in custom model. 
==[[Digital technologies/3D printing/3D printing- Intermediate/Print Orientation|Print Orientation]]==
<nowiki>https://www.youtube.com/watch?v=OqRbSkX5IJk</nowiki>

Print orientation is crucial to the success of the 3D model print. It heavily influences the speed and quality of the result. There are many different factors to consider when choosing how to orient your print.

Understand the build volume of the printer. The print needs to be oriented in a way that it will physically fit in the printer when printed. If the print is too big, the model can be divided into multiple parts to be printed separately. The Ultimaker 2+ printers have a build volume of 223 x 223 x 205mm.

To determine which face of your design should face down on the build plate, it is important to choose the best face for stability and bed adhesion. This is typically a face that is large enough to provide stability and a flat surface to minimize the need for build plate adhesion.

It is also important to consider the mechanical stresses that your part will experience. Orient the part so that the direction of minimum applied stress is along the build direction (vertical). The build direction is typically weaker since it relies on the bond strength between layers rather than the strength of the material. The print should also be oriented to minimize print time and supports used. These two factors are connected as the more supports needed, the longer the print will be. 

==[[Digital technologies/3D printing/3D printing- Intermediate/Post-Processing 3D prints|Post-Processing 3D prints]]==
 There are a number of post processing possibilities with 3D printed models. The options available are dependent on the material used. In this section, post-processing possibilities for PLA that are available in the Makerspace will be explored. The video below will explain the basics of post-processing. Everything used in the video is available at the finishing station in the Makerspace.

<nowiki>https://www.youtube.com/watch?v=l6dI3RDorwk</nowiki>

<nowiki>https://www.youtube.com/watch?v=ZTE9bJyUO_8</nowiki>

The most basic post-processing procedure is support removal. The Ultimaker 2+ printers in Makerspace are single extruder printers which means the supports are printed using the same material as the main model. Typically, the supports are easily removed by breaking them off the printed model. However, when supports are placed in tight corners or hard to reach places, additional tools such as pliers will be needed to remove the material. Dual extruder printers will allow you to print the supports with a different soluble material than the main part. This means the difficult to remove supports can be dissolved away by soaking it in another liquid.

Another basic procedure is sanding. 3D printed parts will often have rough surfaces from the layers. Sanding is the easiest way to create a smooth surface. At the finishing station, there are sandpaper of different grit sizes to sand down your model. There are also files at the station for edges and holes. It is important to sand the surfaces in circular motions to ensure the aesthetics of the model.

Gluing the model is one of the most common post-processing options to attach parts together. There are many glue options available at the Makerspace, including super glue and hot glue. Hot glue is easy to use but it will leave a visible gap as 2-3mm of glue is needed to secure the parts together. Hot glue is also not very strong. Super glue is a good option for a seamless seal that cures fast.

Painting is one of the most common finishing processes. The model needs to be primed first before being painted. The model should be sanded with a low and then medium grit sandpaper. Prime the model with a coat of primer paint. Once everything is dry, you can start painting your model with other colors. Acrylic paint and paintbrushes are available to use at Makerspace.

==[[Digital technologies/3D printing/3D printing- Intermediate/Bed Levelling, Filament Change|Bed Levelling, Filament Change]]==

===Bed Levelling===
<nowiki>https://www.youtube.com/watch?v=0shirFB7o1s</nowiki>

If the printer is not printing properly (especially if the issue is noticeable on the very first layers of the print, where a difference in the layer height is noticeable), the build plate level may need to be adjusted. For minor adjustments, this can be done by using the three knobs (thumb screws) on the underside of the plate. For more major adjustments (>1mm), the build plate should be leveled through the printer’s onboard software by going to Maintenance→Build Plate, and following the onscreen instructions. If unsure, always use the latter method. The calibration cards needed are at the finishing station. However, in Makerspace, bed levelling should only be performed by the staff.

===Filament Change===
<nowiki>https://www.youtube.com/watch?v=9v1w_dmpLu0</nowiki>

To change the filament on an Ultimaker 2+ printer, go to Material→Change in the printer’s user interface and follow the onscreen instructions. If ever the filament has almost run out, or if you desire to change the color of a print midway, you may navigate to Pause→Change Material and following the onscreen instructions. If changing mid-way, it is recommended that the older filament be completely purged from the nozzle using the new filament. Otherwise, the result will not be good. Again, within the Makerspace, this should only be done by the staff working.

==[[Digital technologies/3D printing/3D printing- Intermediate/Selecting Nozzle Sizes|Selecting Nozzle Sizes]]==
[[File:Nozzle Size.png|thumb]]
Nozzle size is the first decision to make when 3D printing. Within Makerspace, there are four options of nozzle size using the Ultimaker 2+, 0.25mm, 0.4mm, 0.6mm, and 0.8mm. Choosing between the options depends on the fine details of the model and the print speed required.

*A smaller nozzle size will allow for finer details and better dimension accuracy. However, it will also take longer to print the model.
*A larger nozzle can provide faster print time and also create stronger prints.
*A smaller nozzle diameter can cause it to be more difficult to print with overhangs as each layer has less width to adhere to the next one.
*However, with a smaller nozzle, the supports are easier to remove as the printer will use less material for supports making it easier to break away.
*A larger nozzle is able to print with less infill as the walls would be thicker to ensure strength.

==Troubleshooting==

<nowiki>https://www.youtube.com/watch?v=R-CMotQ-nqI&t=249s</nowiki>
{| class="wikitable"
|'''Issue (symptom)'''
|'''Possible Cause (diagnosis)'''
|'''Potential Fix (cure)'''
|-
|Warping
|Not enough/too much model base surface contact to the print bed
|Add build plate adhesion such as a brim or a raft. Refer to adhesion section for further explanation.
|-
| rowspan="3" |Bad adhesion
|Dirty build plate
|Clean off the build plate first. Debris and oils from your fingers can cause difficulties for the material to stick.
|-
|Not enough/too much model base surface contact to the print bed
|Add build plate adhesion such as a brim or a raft.
|-
|Uneven print bed/Bed too far from nozzle at initial layer
|This is the least likely possibility. Relevel the build plate. Ask a Makerspace staff for more details.
|-
| rowspan="2" |No extrusion
|No filament
|Replace filament spool. Ask a Makerspace staff to replace the filament spool.
|-
|Filament clog
|Keep in mind that it is uncommon that this is the actual cause of lack of extrusion. Ask a Makerspace employee to assist with further diagnosis.
|-
| rowspan="3" |Underextrusion
|The forwarding mechanism (gearbox) ground through the filament
|Move the filament out of the forwarding mechanism. Use the change material feature to speed up the removal. While the mechanism is whirring to remove the material, pull slightly on the filament, at the back of the printer for the mechanism to grab. Break the filament clean off at the section where the filament was ground, clean up the end by cutting it off. Re-forward the material into the printer, making sure the right material is chosen in the menu.
|-
|Wet (very brittle) filament
|Remove wet section of the filament (0.25 to 0.5m length) and re-load. Ask a Makerspace staff for further support.
|-
|Filament clog
|Keep in mind that it is uncommon that this is the actual cause of lack of extrusion. Ask a Makerspace employee to assist with further diagnosis.
|-
|Print not level
|Model not well seated on bed (in slicer)
|Use the snap to bed feature in your slicer (when available), add a brim to preview which flat sections are well seated on the bed
|-
|Drooling
|No supports when needed
|Add supports. Refer to the supports section.
|}

==References==
<references />

File:Adhesion.png

2023-08-28T22:14:57Z

Cecilial:

Adhesion

File:Supports.png

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Cecilial:

Supports

Digital technologies/3D printing/3D printing- Intermediate

2023-08-28T21:29:20Z

Cecilial: /* Selecting Nozzle Sizes */

File:Nozzle Size.png

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Cecilial:

NozzleSize

Digital technologies/3D printing/3D printing- Intermediate

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Cecilial:

Digital technologies/3D printing/3D printing- Intermediate

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Cecilial:

Digital technologies/3D printing/3D printing- Intermediate

2023-08-28T20:05:18Z

Cecilial:

File:Sheet Lamination .png

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Cecilial:

Sheet Lamination 3D Printing

File:Directed Energy Deposition.png

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Cecilial:

Directed Energy Deposition

File:Binder Jetting.png

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Cecilial:

Binder Jetting 3D Printing

File:Material Jetting.png

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Cecilial:

Material Jetting 3D printing

File:Powder Bed Fusion.png

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Cecilial:

Powder Bed Fusion 3D Printing

File:Vat Polymerization .png

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Cecilial:

Vat Polymerization 3D printing

File:Material Extrusion .png

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Cecilial:

Material Extrusion 3D printing

Digital technologies/3D printing/3D modeling- Intermediate/Using Parametric NURBS Software

2023-08-25T19:38:08Z

Cecilial:

{{#lsth:Digital technologies/3D printing/3D modeling- Intermediate|[[Digital technologies/3D printing/3D modeling- Intermediate/Using Parametric NURBS Software|Using Parametric NURBS Software]]}}

==[[Digital technologies/3D printing/3D modeling- Intermediate/Using Parametric NURBS Software|Introduction to Fusion360]]==

<youtube>5hComh1hFzY</youtube>

<youtube>1Ff_NcZhBSo</youtube>

TinkerCAD is known for its simplicity, meaning it is easy to learn and use. However, its capabilities are limited. It uses a drag and drop method to create basic geometries. Theses shapes can be grouped to create more complex geometries but it takes more time to design something complex and has less flexibility. Fusion<ins> </ins>360 is a sketch-based CAD modeling software that allows for users to completely customize their design. It allows users to design 3D objects using 2D sketches.

Fusion 360 offers 3D CAD modeling, PCB design, and 3D simulation capabilities. It is a fee-based subscription software, however, a free version is offered for personal use. The free version has some limited capabilities but most of the 3D CAD features are offered. Even with the limited features it offers more design options than TinkerCAD. To download the software, you can use your AutoCAD account and follow the link below: <nowiki>https://www.autodesk.ca/en/products/fusion-360/personal</nowiki>

Just like TinkerCAD, and with any CAD modeling software you choose to use<ins>,</ins><s>. Y</s><ins> y</ins>ou can export your part designs as an STL file. Using this file format, you can use any slicer of your choice to slice the design into a gcode file to print.

=== Fusion 360 User Interface ===
[[File:User Interface of Fusion 360.png|center|959x959px]]
There are 5 main areas of the user interface. When the software is first launched, you should be seeing the screen above.

# Data Panel: On the left is the data panel. It displays pinned and recent projects, providing easy access to these projects for the users. It will also display sample projects that corresponds to the tutorials offered by AutoCAD. Users can also upload their projects to be shared with others for collaboration.
# Tool Bar: On the top of the screen sits the tool bar. Through this, you can use any of the features displayed to manipulate the 3D model you create. The shortcuts can be customized to display the ones you favour.
# Browser: Located at the top left of the main screen. It displays the model design with a file tree structure listing all the components, bodies and constructing plane. The files can be navigated through by clicking on their names. They can also be renamed by double clicking. The files can be collapsed using the triangles. The visibility of the bodies and planes can be toggled by clicking on the lightbulb.
# Timeline: The timeline of the design history is displayed at the bottom of the screen. This is a special feature of Fusion<ins> </ins>360 that is different from other CAD software. It keeps a record of the construction of the 3D model allowing the users to playback the building of the model. This feature also allow<ins>s</ins> users to add to the model from a previous state of the model.
# Navigation bar: The navigation bard allows users to change the view of the model. These features exist<s>s</s> as shortcuts when used with a mouse. For this reason, it is recommended to create CAD models using a physical mouse instead of a track pad. Some features include:
#* Zoom In/Out by scrolling up/down with the mouse.
#* Pan the model by holding down the wheel of the mouse.
#* Orbit the model by holding down control + wheel.

=== Sketching ===
The sketch function is the most important feature of a CAD program. It allows users to sketch 2D drawings as the base to create 3D objects.
[[File:Sketch Interface.png|center|650x650px]]
To create a rectangle, first click on “Create Sketch” from the tool bar above. Select the desired sketch plane. In the example above, YZ plane was selected. This is the plane which the 2D sketch will be created. You’ll notice the tool bar above has transformed to display sketch functions. Select “2-Point Rectangle” from the tool bar. Click on the origin of the sketch plane and drag to create a desired rectangle. The sketch features are defined with reference to the origin to position it in space. It is why it is recommended to have one vertex of the sketch to be defined as the origin. After the rectangle is drawn, you can define the dimensions of the 2 sides of the rectangle. You can toggle between the dimensions by using the “Tab” key on your keyboard. Press enter to confirm the sketch.
[[File:Fusion 360 Rectangle Sketch.png|center|600x600px]]
Next, the line tool will be introduced. Drawing a line is the most simple and versatile function of sketch. It will allow you to create any shapes you will need. Select the “Line” option from the tool bar. Hover your mouse over the rectangle, the mouse will be drawn to the line and an ‘X’ will appear. This means that one end of the line will intersect with the rectangle. Move the mouse towards the middle of the line on the rectangle until a triangle icon shows up. This signifies the midpoint of the line. Click to create the start of the line segment. Drag the mouse to create the line and click again to create the end of the line. You can also manipulate the dimension of the line manually by entering the value.
[[File:Fusion 360 Line Sketch.png|center|649x649px]]
To draw the line at an angle, drag the line out at an angle. At this point, there should be an angle dimension displayed. This value can be altered manually.

To create an arc, select “Create” -> “Arc” -> “Tangent Arc” from the tool bar. This will create an arc tangent to two other entities. Left click on the vertex of where you would like the arc to connect. Then click on the other vertex to connect. Alternative to create arcs include 3-point arcs where you select the two vertex and the middle point of the arc or center point arc when the arc is create<ins>d</ins> by finding the center of the arc.
[[File:Arc Sketch.png|center|648x648px]]

In order for a 2D sketch to be converted to 3D model, the 2D profile has to be a closed shape. This means all the lines and entities have to form a closed loop. This will be indicated with a light-blue shading inside the sketch.

=== Extrusion ===
The simplest way to create a 3D model is by extruding a 2D sketch, which adds a third dimension to the 2D sketch. Select “Extrude” from the toolbar. Hover the mouse over the sketch, closed shapes that can be extruded will be highlighted when hovered on. To select multiple shapes, left click on both shapes. In the extrusion settings that pops up on the right, enter the value for the third dimension of the sketch, the width. Click “OK” to confirm the extrusion.
[[File:Extrusion example.png|center|650x650px]]
You can select a new surface from the extruded object to sketch on. To do so, select “Create Sketch” and select the surface you would like to sketch on as the plane. Afterwards continue to sketch like normal.

Extrusion can also be used to cut. Sketch on the surface of the shape the geometry you would like to cut. Select “Extrude” tool and select the shapes you would like to cut. To remove material, enter a negative value in the dimension window. This indicates the direction you would like the extrusion to occur. On the screen, it will display a red region to indicate material removal. Press enter to confirm the operation.
[[File:Extrusion cut example.png|center|650x650px]]

=== Mirror ===
The mirror tool is an extremely powerful tool that can save the user a lot of time in creating the 3D models. This is especially useful when creating symmetrical objects. It allows users to mirror solid or small features. It does require the user to define the plane to mirror the features. There are many ways to create the plane. One of which is to “Offset Plane”
[[File:Mirror Example.png|center|650x650px]]

Under the “Construct” drop-down menu from the toolbar, select “Offset Plane”. Select a surface to offset from. This surface should be parallel from the plane you would like to create. Now enter the dimension you would like to offset the plane from the surface. Press enter when completed.

After the plane has been created, you can now mirror the features. Select “Mirror” under the drop<ins>-</ins> down menu from “Create” from the toolbar. Under “Type” parameter, you can select bodies, faces, features, or components. After the type has been selected, click on “Select” by Object and then the features you would like to mirror, you can also click on the features from the design history timeline. Then click on “Select” by Mirror Plane and the plane you would to mirror from. Now a preview will be displayed<ins>,</ins> to confirm press enter.

=== Fillet ===
Filleting the edges is a feature that is offered in Fusion 360 and not TinkerCAD. It can easily elevate your models. It creates rounded surfaces by adding or removing from a solid model.
[[File:Fillet Example.png|center|650x650px]]

# Select “Fillet” under the modify menu from the tool bar.
# Click on the edges you would like to round out.
# Enter a radius value to round the edges out to.
# Click “OK” to finalize.

Digital technologies/3D printing/3D modeling- Intermediate/CAD Extensions

2023-08-25T19:36:50Z

Cecilial:

{{#lsth:Digital technologies/3D printing/3D modeling- Intermediate|[[Digital technologies/3D printing/3D modeling- Intermediate/CAD Extensions|CAD Extensions]]}}

In the beginner section of 3D modeling, you were introduced to TinkerCAD. In the instructions, you were instructed to export your 3D designs as a STL or OBJ file. In this section, the differences between different CAD file formats will be discussed.

=== [https://en.wikipedia.org/wiki/STL_(file_format) Standard Triangle Language (*.STL)] ===
[[File:STL format.png|thumb|Facets used to represent a cube and a sphere.]]
[[File:Vector coordinates of STL format.png|thumb|305x305px|Visual representation of the vertices and the normal vector.]]
STL files are the most used file format in 3D printing and 3D modeling. Most 3D printers support the file format. Many of the 3D printable models online are also found in STL file format. STL stands for stereolithography, a 3D printing process created at 3D Systems in <ins>the </ins>1980s. STL file format encodes the surface geometry of a 3D object. This is done through tessellation, a process of tiling a surface with one or more geometric shapes so there are no overlaps or gaps. The basic method of tessellating the outer surface of 3D models is through the use of tiny triangles (called “facets”) and store information about the facets in a file. For example, in the figure below, it shows how a cube can be represented by 12 triangles while 17000+ triangles are needed to represent a sphere. Since triangles consist of three straight edges, it can be difficult to approximate curved geometries. To do so, mesh density is increased, and individual triangle’s size is decreased.

STL file format stores the information as the coordinates of the vertices and the components of the unit normal vector to the triangle. The normal vector point outwards of the 3D model.
[[File:STL tessellation .png|left|thumb|Invalid tessellation on the left, acceptable tessellation on the right]]
There are a couple of rules for tessellation and storing information. The vertex rule states that each triangle must share two vertices with its neighbouring triangles.

The orientation rule states that the orientation of the facet must be specified in two ways. The direction of the normal should point outwards, and the vertices are listed in counter-clockwise when looking at the object from the outside.

The all-positive octant rule states that the coordinates of the triangle vertices must all be positive. This ensures that all coordinates stored would be in the positive which would save space in the file. Finally, the triangle sorting rule recommends that the triangles appear in ascending z-value order. This is a recommendation rather than a rule as it helps the software slice the models faster.
[[File:STL orientation rule.png|center|thumb|525x525px|Visual representation of the orientation rule.]]

=== [https://en.wikipedia.org/wiki/Wavefront_.obj_file Wavefront OBJ (*.OBJ)] ===
OBJ is a crucial file format in 3D printing. It is generally preferred for multi-colour 3D printing. Often, it is used a s an interchange format for non-animated 3D models. OBJ file format stores information about 3D models by encoding the surface geometry of the model. It also stores information about its colour and texture. It does not store any data about animations or scene. It is open source and neutral. Therefore, it is often used to share 3D models since many CAD software supports the format.
[[File:OBJ file .png|thumb|Freeform curves on 3D model surface]]
It differs from STL since it stores colour and texture information. STL is an older file format that is missing modern features. It does not support multi colour printing or high resolution prints. OBJ can approximate surface geometry well without drastically increasing the file size. It also supports multiple colours and textures in the same model.

OBJ encodes surface geometry of a 3D object in many different methods: Tessellation with polygonal faces, freeform curves and freeform surfaces. Similar to STL, OBJ allows tessellation of the surfaces with simple geometric shapes like triangles or more complex polygon. This is the simplest way to describe surface geometry. However, approximating curved surfaces with polygons will introduce coarseness and geometric deviation from the model. The size of the polygons can be decreased to increase the quality of the prints. However, this can lead to giant file sizes which can be difficult for 3D printers to handle. It is important to find the right balance between print quality and file sizes.

The surface geometry can also be defined using freeform curves. The user defines a collection of free form curves that runs along the surface of the model. The surface is then approximated using the collection of curves. It is more complicated than polygonal faces, but it allows for fewer data to describe the same surface. The curved lines can be described using freeform curves with a few mathematical parameters. It allows for higher quality encoding without drastically increasing the file size.

=== DS Solidworks Parts (*.SLDPRT) and DS Solidworks Assemblies (*.SLDASM) ===
Sldprt file formats are native SolidWorks file extensions. It provides details on specific parts within a system. This is a software specific file format. Opening SolidWorks files in slicers and other software may cause some corruption of your designs. However, because it is software specific, it contains the most information about your models. As such, you should do all your modeling while the files are in native format

=== [https://en.wikipedia.org/wiki/ISO_10303 ISO10303 - Standard for the Exchange of Product model data (*.STP, *.STEP)] ===
STEP file format is a neutral file format. It is the most common file format used to share 3D designs. This allows users to open others’ designs using the software of their choice. It stores 3D images in an ASCII format. While STEP files can be opened with most CAD software. It is not easily edited. The model will display as a finalized object. Users cannot edit specific dimensions or features of the model.

===Polygonal Formats===

*[https://en.wikipedia.org/wiki/STL_(file_format) Standard Triangle Language (*.STL)]
*[https://en.wikipedia.org/wiki/Wavefront_.obj_file Wavefront OBJ (*.OBJ)]
*[https://en.wikipedia.org/wiki/3D_Manufacturing_Format 3D Manufacturing Format (*.3MF)]

===NURBS Formats===

====Standard====

*[https://en.wikipedia.org/wiki/ISO_10303 ISO10303 - Standard for the Exchange of Product model data (*.STP, *.STEP)]
*[https://en.wikipedia.org/wiki/AutoCAD_DXF AutoCAD Drawing Exchange Format (*.DXF/*.DWG)]
*[https://en.wikipedia.org/wiki/IGES Initial Graphics Exchange Specification (*.IGES)] (standard last updated 1996)

====Software-Specific====

*DS Solidworks Parts (*.SLDPRT)
*DS Solidworks Assemblies (*.SLDASM)
*DS CATIA V5 Parts (*.CGR/*.CATPart)
*DS CATIA V5 Assemblies (*.CGR/*.CATProduct)
*PTC Creo Parts (*.PRT)
*PTC Creo Assemblies (*.ASM)

*Fusion 360 (*.F3D)

It should be noted that Fusion360 stores files on the cloud, such that locally saved .f3d files are not commonly encountered. It should also be noted that OnShape does not have a file format given it is hosted entirely on the cloud.

Digital technologies/3D printing/3D modeling- Intermediate/TinkerCAD (contd.)

2023-08-25T19:32:55Z

Cecilial:

{{#lsth:Digital technologies/3D printing/3D modeling- Intermediate|[[Digital technologies/3D printing/3D modeling- Intermediate/TinkerCAD (contd.)|TinkerCAD (contd.)]]}}
[[File:Heart Button TinkerCAD.png|thumb|Heart button CAD model|200x200px|alt=]]
In the beginner section of 3D modeling, you learned how to group shapes together. In advanced TinkerCAD, you will use the skills you have gained to create more complex shapes. TinkerCAD provides you with basic geometries such as cubes and cylinders. You can combine these shapes to create more complex geometries such as a house using the group function. To create even more complicated designs, you can combine shapes to be used to create complex holes

<youtube>kVXkdLfK1kw</youtube>

The example below will walk you through the making of a heart button. It will involve grouping shapes together in order to create a more complex shape and feature
[[File:Heart_Button_Construction.png|alt=|thumb|351x351px|Combining simple shapes like cylinders and cubes to create heart shape. ]]
# Add a box shape to the workspace. Make sure the dimension of the box has the thickness of the desired button. This will serve as the point of the heart.
# Add two cylinders with the same thickness as the box to two edges of the box. Set the diameter of the cylinder as the width of the box. This will create the humps of the heart.
# Using the round roof object, size it to the appropriate dimension for the button hoop.
# Copy and paste<s>r</s> a second round roof object and make it slightly smaller to be used to create the hole for the button hoop.
# Turn the object into a hole and position it accordingly.
# Finally, group the shapes together and the button is completed.

Digital technologies/3D printing/3D modeling- Intermediate

2023-08-25T19:32:08Z

Cecilial:

TinkerCAD is nice for smaller parts with very little complexity. However, since it is not [https://en.wikipedia.org/wiki/Non-uniform_rational_B-spline NURBS] based nor parametric, it lacks major functionality. It is strongly suggested at this stage that TinkerCAD, Blender, Cinema 4D or other [https://en.wikipedia.org/wiki/Polygonal_modeling polygonal modelling] (non-NURBS) applications be set aside for parametric CAD software, such as [https://www.autodesk.ca/en/products/fusion-360 Autodesk Fusion 360] ([https://www.autodesk.ca/en/products/fusion-360/students-teachers-educators free for students. teachers, and educators]), [https://www.solidworks.com/ Dassault Systèmes Solidworks] (available through Remote Apps) or [https://www.onshape.com/en/ PTC OnShape] (completely online, free for students and educators) be used for mechanical design, as models made with such software contain much richer data that allows going from CAD models to manufacturing data. Polygonal modelling remains, however, an important tool for Scan to CAD, and such the intermediate CAD user should have a complete understanding of polygonal modelling software such as TinkerCAD.

==[[Digital technologies/3D printing/3D modeling- Intermediate/TinkerCAD (contd.)|Complex Shapes in TinkerCAD]]==
[[File:Heart Button TinkerCAD.png|thumb|Heart button CAD model|200x200px|alt=]]
In the beginner section of 3D modeling, you learned how to group shapes together. In advanced TinkerCAD, you will use the skills you have gained to create more complex shapes. TinkerCAD provides you with basic geometries such as cubes and cylinders. You can combine these shapes to create more complex geometries such as a house using the group function. To create even more complicated designs, you can combine shapes to be used to create complex holes

<youtube>kVXkdLfK1kw</youtube>

The example below will walk you through the making of a heart button. It will involve grouping shapes together in order to create a more complex shape and feature
[[File:Heart_Button_Construction.png|alt=|thumb|351x351px|Combining simple shapes like cylinders and cubes to create heart shape. ]]
# Add a box shape to the workspace. Make sure the dimension of the box has the thickness of the desired button. This will serve as the point of the heart.
# Add two cylinders with the same thickness as the box to two edges of the box. Set the diameter of the cylinder as the width of the box. This will create the humps of the heart.
# Using the round roof object, size it to the appropriate dimension for the button hoop.
# Copy and paste<s>r</s> a second round roof object and make it slightly smaller to be used to create the hole for the button hoop.
# Turn the object into a hole and position it accordingly.
# Finally, group the shapes together and the button is completed.

== [[Digital technologies/3D printing/3D modeling- Intermediate/Design for 3D Printing|Design for 3D Printing]] ==
There are some important things to note when modeling for 3D printing. It is important to optimize the print by decreasing print time and material while ensuring accuracy and strength of the part.

# Divide your model into smaller more manageable parts. There are many designs with complex details or large dimensions that would be more manageable prints if split into multiple parts. [[File:Multiple parts 3D print.png|center|thumb|599x599px|3D printed hand built with multiple parts. Finger is attached afterwards. ]]
# Try to ensure that there is one flat surface on the print. This will allow easier print set-up. The flat side can adhere to the build plate, minimizing the need for additional build plate adhesion.[[File:Prints in different orientation.png|center|thumb|300x300px|Traffic cone printed in two different orientations. It demonstrates the optimal orientation with the least amount of supports. ]]
# Avoid floating parts. All aspect of the model should be connected to the main model. Minimize overhangs in the model as well. This will prevent wasted time and material to print supports.[[File:Supports under floating parts.png|center|thumb|480x480px|Printed gearbox with floating parts with supports under them. ]]
# FDM printing has limited capabilities with dimensional accuracy. It is recommended to prevent printing horizontally oriented holes of the smaller size. These holes are often deformed and printed with difficult to remove supports.[[File:Holes printed vertically and horizontally..png|center|thumb|500x500px|Holes printed vertically on the left and horizontally with the layers on the right. ]]
# Printed parts are stronger in one direction than another. It is important to keep this in mind when designing. Prints will be weaker in the areas where the layers meet. This means that printed parts have low tensile strength along the Z-axis. The prints will be the strongest in planes parallel to the build surface.[[File:Layers printed in different axis.png|center|thumb|500x500px]]
# Exaggerate the details of your designs. This is an important thing to keep in mind. In order for details to show up on small designs, you should make your cuts deeper and bigger. It can also be helpful to make slender designs thicker.[[File:Details on 3D prints.png|center|thumb|450x450px|Details on CAD on the left with the same details printed on the right. ]]
# Round surfaces will not show up smoothly. Since FDM prints in layers, it will cause the rounded surfaces to look jagged. To achieve a smooth surface, additional processing will be required. [[File:3D printed surface .png|center|thumb|449x449px|3D printed surface with all the layers before and after additional processing. ]]

If your design is to be used in (electro-)mechanical assemblies in which there are interfacing components, it is important that you understand three basic tolerancing concepts and to keep them in the back of your mind when modeling or more generally designing these assemblies.

# Form: The form of a part refers to the overall dimensions and the shape of the exterior surfaces of a component. Think of a flaw referring to form as a print that ended up not matching the base geometry that was used to create it in CAD due to adverse physical variables during the printing process. Examples follow:
## A ''sphere'' may end up slightly ''oval'' once printed due to improper cooling, etc.;
## A pillar might end up tilted to one side due to improper belt tension between the belt axes, etc.;
## A pin feature might end up too large to fit its mating hole due to the printer outputting too much material when producing the outer walls of the feature (the inverse can also be true).
# Position: Position refers to the distance separating a feature and an (ideally) meaningful reference (i.e.: the distance between a hole and the side of a part, or between two holes). Thankfully, flaws pertaining to position are rare on a properly tuned printer, as the printer does not have any information about existing references other than the build plate. If tuned properly, the printer will always print a feature at a position (X,Y,Z) distance relative to another feature, because that is what the gCode will tell it to do. You can imagine, however, that if the part is warped, the 'build plate reference' is no longer valid, and such, warped parts almost always have features out of position ''unless the meaningful reference (interfacing feature) used in the design is not the build plate''. However, since the build plate reference is such an important one to define the Z position of features (for the printer, that is), making your meaningful reference something other than the build plate does not always guarantee you good positional tolerance independent of warping.
# Surface: The surface finish of a part is a rather complex subject. In 3D printing, and for typical applications of 3D printed parts, it mostly refers to the mean (statistical) difference between the height of cusps and valleys on a part and their deviation from that mean, at a macroscopic level. The most important consideration is that when 3D printing, most surface finishes are quite rough (deviate significantly from the mean), and thus are sanded down considerably to knock out the cusps left by the printer. This post processing can negatively affect the form of the final part.

Note that ''a proper mechanical fit between components demands a good tolerance on form, feature position, and surface finish'', such that it is typically impossible to obtain a proper fit when 3D printing, and that if you are considering the 3D printing of critically interfacing components, 3D printing should not be used unless post processing ''is built into the design''. For mechanical designs, you will notice that a main application is brackets. This is because brackets only need good positional tolerance on holes and mating faces, which 3D printing can almost always provide (the tolerance on form for holes is not that important since they are typically clearance holes). However, since some brackets are easily laser cut, 3D printing brackets is only done under certain specific conditions. It certainly has shown its commercial use in cost cutting by replacing intricate multi-part assemblies by ''generatively designed'' (we'll say computer generated for now) parts, as shown in the picture below.
[[File:Design for 3D Printing Generatively Designed Bracket.jpg|center|thumb|600x600px|A metal 3D printed generatively designed bracket (computer generated from load data, using Finite Element Analysis), likely replacing a multitude of other parts that would have been manufactured using traditional manufacturing methods which would lead to a heavier and more expensive bracket.<ref>CarrusHome (2021). GM Explores 3D printing, generative design for next gen parts. Consulted on 05-05-2022 at <nowiki>https://www.carrushome.com/en/gm-explores-3d-printing-generative-design-for-next-gen-parts/</nowiki></ref>]]

==[[Digital technologies/3D printing/3D modeling- Intermediate/CAD Extensions|CAD File Formats]] ==
In the beginner section of 3D modeling, you were introduced to TinkerCAD. In the instructions, you were instructed to export your 3D designs as a STL or OBJ file. In this section, the differences between different CAD file formats will be discussed.

=== [https://en.wikipedia.org/wiki/STL_(file_format) Standard Triangle Language (*.STL)] ===
[[File:STL format.png|thumb|Facets used to represent a cube and a sphere.]]
[[File:Vector coordinates of STL format.png|thumb|305x305px|Visual representation of the vertices and the normal vector.]]
STL files are the most used file format in 3D printing and 3D modeling. Most 3D printers support the file format. Many of the 3D printable models online are also found in STL file format. STL stands for stereolithography, a 3D printing process created at 3D Systems in <ins>the </ins>1980s. STL file format encodes the surface geometry of a 3D object. This is done through tessellation, a process of tiling a surface with one or more geometric shapes so there are no overlaps or gaps. The basic method of tessellating the outer surface of 3D models is through the use of tiny triangles (called “facets”) and store information about the facets in a file. For example, in the figure below, it shows how a cube can be represented by 12 triangles while 17000+ triangles are needed to represent a sphere. Since triangles consist of three straight edges, it can be difficult to approximate curved geometries. To do so, mesh density is increased, and individual triangle’s size is decreased.

STL file format stores the information as the coordinates of the vertices and the components of the unit normal vector to the triangle. The normal vector point outwards of the 3D model.
[[File:STL tessellation .png|left|thumb|Invalid tessellation on the left, acceptable tessellation on the right]]
There are a couple of rules for tessellation and storing information. The vertex rule states that each triangle must share two vertices with its neighbouring triangles.

The orientation rule states that the orientation of the facet must be specified in two ways. The direction of the normal should point outwards, and the vertices are listed in counter-clockwise when looking at the object from the outside.

The all-positive octant rule states that the coordinates of the triangle vertices must all be positive. This ensures that all coordinates stored would be in the positive which would save space in the file. Finally, the triangle sorting rule recommends that the triangles appear in ascending z-value order. This is a recommendation rather than a rule as it helps the software slice the models faster.
[[File:STL orientation rule.png|center|thumb|525x525px|Visual representation of the orientation rule.]]

=== [https://en.wikipedia.org/wiki/Wavefront_.obj_file Wavefront OBJ (*.OBJ)] ===
OBJ is a crucial file format in 3D printing. It is generally preferred for multi-colour 3D printing. Often, it is used a s an interchange format for non-animated 3D models. OBJ file format stores information about 3D models by encoding the surface geometry of the model. It also stores information about its colour and texture. It does not store any data about animations or scene. It is open source and neutral. Therefore, it is often used to share 3D models since many CAD software supports the format.
[[File:OBJ file .png|thumb|Freeform curves on 3D model surface]]
It differs from STL since it stores colour and texture information. STL is an older file format that is missing modern features. It does not support multi colour printing or high resolution prints. OBJ can approximate surface geometry well without drastically increasing the file size. It also supports multiple colours and textures in the same model.

OBJ encodes surface geometry of a 3D object in many different methods: Tessellation with polygonal faces, freeform curves and freeform surfaces. Similar to STL, OBJ allows tessellation of the surfaces with simple geometric shapes like triangles or more complex polygon. This is the simplest way to describe surface geometry. However, approximating curved surfaces with polygons will introduce coarseness and geometric deviation from the model. The size of the polygons can be decreased to increase the quality of the prints. However, this can lead to giant file sizes which can be difficult for 3D printers to handle. It is important to find the right balance between print quality and file sizes.

The surface geometry can also be defined using freeform curves. The user defines a collection of free form curves that runs along the surface of the model. The surface is then approximated using the collection of curves. It is more complicated than polygonal faces, but it allows for fewer data to describe the same surface. The curved lines can be described using freeform curves with a few mathematical parameters. It allows for higher quality encoding without drastically increasing the file size.

=== DS Solidworks Parts (*.SLDPRT) and DS Solidworks Assemblies (*.SLDASM) ===
Sldprt file formats are native SolidWorks file extensions. It provides details on specific parts within a system. This is a software specific file format. Opening SolidWorks files in slicers and other software may cause some corruption of your designs. However, because it is software specific, it contains the most information about your models. As such, you should do all your modeling while the files are in native format

=== [https://en.wikipedia.org/wiki/ISO_10303 ISO10303 - Standard for the Exchange of Product model data (*.STP, *.STEP)] ===
STEP file format is a neutral file format. It is the most common file format used to share 3D designs. This allows users to open others’ designs using the software of their choice. It stores 3D images in an ASCII format. While STEP files can be opened with most CAD software. It is not easily edited. The model will display as a finalized object. Users cannot edit specific dimensions or features of the model.

===Polygonal Formats===

*[https://en.wikipedia.org/wiki/STL_(file_format) Standard Triangle Language (*.STL)]
*[https://en.wikipedia.org/wiki/Wavefront_.obj_file Wavefront OBJ (*.OBJ)]
*[https://en.wikipedia.org/wiki/3D_Manufacturing_Format 3D Manufacturing Format (*.3MF)]

===NURBS Formats===

====Standard====

*[https://en.wikipedia.org/wiki/ISO_10303 ISO10303 - Standard for the Exchange of Product model data (*.STP, *.STEP)]
*[https://en.wikipedia.org/wiki/AutoCAD_DXF AutoCAD Drawing Exchange Format (*.DXF/*.DWG)]
*[https://en.wikipedia.org/wiki/IGES Initial Graphics Exchange Specification (*.IGES)] (standard last updated 1996)

====Software-Specific====

*DS Solidworks Parts (*.SLDPRT)
*DS Solidworks Assemblies (*.SLDASM)
*DS CATIA V5 Parts (*.CGR/*.CATPart)
*DS CATIA V5 Assemblies (*.CGR/*.CATProduct)
*PTC Creo Parts (*.PRT)
*PTC Creo Assemblies (*.ASM)

*Fusion 360 (*.F3D)

It should be noted that Fusion360 stores files on the cloud, such that locally saved .f3d files are not commonly encountered. It should also be noted that OnShape does not have a file format given it is hosted entirely on the cloud.

==[[Digital technologies/3D printing/3D modeling- Intermediate/Using Parametric NURBS Software|Introduction to Fusion360]]==

<youtube>5hComh1hFzY</youtube>

<youtube>1Ff_NcZhBSo</youtube>

TinkerCAD is known for its simplicity, meaning it is easy to learn and use. However, its capabilities are limited. It uses a drag and drop method to create basic geometries. Theses shapes can be grouped to create more complex geometries but it takes more time to design something complex and has less flexibility. Fusion<ins> </ins>360 is a sketch-based CAD modeling software that allows for users to completely customize their design. It allows users to design 3D objects using 2D sketches.

Fusion 360 offers 3D CAD modeling, PCB design, and 3D simulation capabilities. It is a fee-based subscription software, however, a free version is offered for personal use. The free version has some limited capabilities but most of the 3D CAD features are offered. Even with the limited features it offers more design options than TinkerCAD. To download the software, you can use your AutoCAD account and follow the link below: <nowiki>https://www.autodesk.ca/en/products/fusion-360/personal</nowiki>

Just like TinkerCAD, and with any CAD modeling software you choose to use<ins>,</ins><s>. Y</s><ins> y</ins>ou can export your part designs as an STL file. Using this file format, you can use any slicer of your choice to slice the design into a gcode file to print.

=== Fusion 360 User Interface ===
[[File:User Interface of Fusion 360.png|center|959x959px]]
There are 5 main areas of the user interface. When the software is first launched, you should be seeing the screen above.

# Data Panel: On the left is the data panel. It displays pinned and recent projects, providing easy access to these projects for the users. It will also display sample projects that corresponds to the tutorials offered by AutoCAD. Users can also upload their projects to be shared with others for collaboration.
# Tool Bar: On the top of the screen sits the tool bar. Through this, you can use any of the features displayed to manipulate the 3D model you create. The shortcuts can be customized to display the ones you favour.
# Browser: Located at the top left of the main screen. It displays the model design with a file tree structure listing all the components, bodies and constructing plane. The files can be navigated through by clicking on their names. They can also be renamed by double clicking. The files can be collapsed using the triangles. The visibility of the bodies and planes can be toggled by clicking on the lightbulb.
# Timeline: The timeline of the design history is displayed at the bottom of the screen. This is a special feature of Fusion<ins> </ins>360 that is different from other CAD software. It keeps a record of the construction of the 3D model allowing the users to playback the building of the model. This feature also allow<ins>s</ins> users to add to the model from a previous state of the model.
# Navigation bar: The navigation bard allows users to change the view of the model. These features exist<s>s</s> as shortcuts when used with a mouse. For this reason, it is recommended to create CAD models using a physical mouse instead of a track pad. Some features include:
#* Zoom In/Out by scrolling up/down with the mouse.
#* Pan the model by holding down the wheel of the mouse.
#* Orbit the model by holding down control + wheel.

=== Sketching ===
The sketch function is the most important feature of a CAD program. It allows users to sketch 2D drawings as the base to create 3D objects.
[[File:Sketch Interface.png|center|650x650px]]
To create a rectangle, first click on “Create Sketch” from the tool bar above. Select the desired sketch plane. In the example above, YZ plane was selected. This is the plane which the 2D sketch will be created. You’ll notice the tool bar above has transformed to display sketch functions. Select “2-Point Rectangle” from the tool bar. Click on the origin of the sketch plane and drag to create a desired rectangle. The sketch features are defined with reference to the origin to position it in space. It is why it is recommended to have one vertex of the sketch to be defined as the origin. After the rectangle is drawn, you can define the dimensions of the 2 sides of the rectangle. You can toggle between the dimensions by using the “Tab” key on your keyboard. Press enter to confirm the sketch.
[[File:Fusion 360 Rectangle Sketch.png|center|600x600px]]
Next, the line tool will be introduced. Drawing a line is the most simple and versatile function of sketch. It will allow you to create any shapes you will need. Select the “Line” option from the tool bar. Hover your mouse over the rectangle, the mouse will be drawn to the line and an ‘X’ will appear. This means that one end of the line will intersect with the rectangle. Move the mouse towards the middle of the line on the rectangle until a triangle icon shows up. This signifies the midpoint of the line. Click to create the start of the line segment. Drag the mouse to create the line and click again to create the end of the line. You can also manipulate the dimension of the line manually by entering the value.
[[File:Fusion 360 Line Sketch.png|center|649x649px]]
To draw the line at an angle, drag the line out at an angle. At this point, there should be an angle dimension displayed. This value can be altered manually.

To create an arc, select “Create” -> “Arc” -> “Tangent Arc” from the tool bar. This will create an arc tangent to two other entities. Left click on the vertex of where you would like the arc to connect. Then click on the other vertex to connect. Alternative to create arcs include 3-point arcs where you select the two vertex and the middle point of the arc or center point arc when the arc is create<ins>d</ins> by finding the center of the arc.
[[File:Arc Sketch.png|center|648x648px]]

In order for a 2D sketch to be converted to 3D model, the 2D profile has to be a closed shape. This means all the lines and entities have to form a closed loop. This will be indicated with a light-blue shading inside the sketch.

=== Extrusion ===
The simplest way to create a 3D model is by extruding a 2D sketch, which adds a third dimension to the 2D sketch. Select “Extrude” from the toolbar. Hover the mouse over the sketch, closed shapes that can be extruded will be highlighted when hovered on. To select multiple shapes, left click on both shapes. In the extrusion settings that pops up on the right, enter the value for the third dimension of the sketch, the width. Click “OK” to confirm the extrusion.
[[File:Extrusion example.png|center|650x650px]]
You can select a new surface from the extruded object to sketch on. To do so, select “Create Sketch” and select the surface you would like to sketch on as the plane. Afterwards continue to sketch like normal.

Extrusion can also be used to cut. Sketch on the surface of the shape the geometry you would like to cut. Select “Extrude” tool and select the shapes you would like to cut. To remove material, enter a negative value in the dimension window. This indicates the direction you would like the extrusion to occur. On the screen, it will display a red region to indicate material removal. Press enter to confirm the operation.
[[File:Extrusion cut example.png|center|650x650px]]

=== Mirror ===
The mirror tool is an extremely powerful tool that can save the user a lot of time in creating the 3D models. This is especially useful when creating symmetrical objects. It allows users to mirror solid or small features. It does require the user to define the plane to mirror the features. There are many ways to create the plane. One of which is to “Offset Plane”
[[File:Mirror Example.png|center|650x650px]]

Under the “Construct” drop-down menu from the toolbar, select “Offset Plane”. Select a surface to offset from. This surface should be parallel from the plane you would like to create. Now enter the dimension you would like to offset the plane from the surface. Press enter when completed.

After the plane has been created, you can now mirror the features. Select “Mirror” under the drop<ins>-</ins> down menu from “Create” from the toolbar. Under “Type” parameter, you can select bodies, faces, features, or components. After the type has been selected, click on “Select” by Object and then the features you would like to mirror, you can also click on the features from the design history timeline. Then click on “Select” by Mirror Plane and the plane you would to mirror from. Now a preview will be displayed<ins>,</ins> to confirm press enter.

=== Fillet ===
Filleting the edges is a feature that is offered in Fusion 360 and not TinkerCAD. It can easily elevate your models. It creates rounded surfaces by adding or removing from a solid model.
[[File:Fillet Example.png|center|650x650px]]

# Select “Fillet” under the modify menu from the tool bar.
# Click on the edges you would like to round out.
# Enter a radius value to round the edges out to.
# Click “OK” to finalize.

== References ==
<references />

Digital technologies/3D printing/3D modeling- Intermediate

2023-08-25T19:27:33Z

Cecilial: /* Complex Shapes in TinkerCAD */

TinkerCAD is nice for smaller parts with very little complexity. However, since it is not [https://en.wikipedia.org/wiki/Non-uniform_rational_B-spline NURBS] based nor parametric, it lacks major functionality. It is strongly suggested at this stage that TinkerCAD, Blender, Cinema 4D or other [https://en.wikipedia.org/wiki/Polygonal_modeling polygonal modelling] (non-NURBS) applications be set aside for parametric CAD software, such as [https://www.autodesk.ca/en/products/fusion-360 Autodesk Fusion 360] ([https://www.autodesk.ca/en/products/fusion-360/students-teachers-educators free for students. teachers, and educators]), [https://www.solidworks.com/ Dassault Systèmes Solidworks] (available through Remote Apps) or [https://www.onshape.com/en/ PTC OnShape] (completely online, free for students and educators) be used for mechanical design, as models made with such software contain much richer data that allows going from CAD models to manufacturing data. Polygonal modelling remains, however, an important tool for Scan to CAD, and such the intermediate CAD user should have a complete understanding of polygonal modelling software such as TinkerCAD.

==[[Digital technologies/3D printing/3D modeling- Intermediate/TinkerCAD (contd.)|Complex Shapes in TinkerCAD]]==
[[File:Heart Button TinkerCAD.png|thumb|Heart button CAD model|200x200px|alt=]]
In the beginner section of 3D modeling, you learned how to group shapes together. In advanced TinkerCAD, you will use the skills you have gained to create more complex shapes. TinkerCAD provides you with basic geometries such as cubes and cylinders. You can combine these shapes to create more complex geometries such as a house using the group function. To create even more complicated designs, you can combine shapes to be used to create complex holes

<youtube>kVXkdLfK1kw</youtube>

The example below will walk you through the making of a heart button. It will involve grouping shapes together in order to create a more complex shape and feature
[[File:Heart_Button_Construction.png|alt=|thumb|351x351px|Combining simple shapes like cylinders and cubes to create heart shape. ]]
# Add a box shape to the workspace. Make sure the dimension of the box has the thickness of the desired button. This will serve as the point of the heart.
# Add two cylinders with the same thickness as the box to two edges of the box. Set the diameter of the cylinder as the width of the box. This will create the humps of the heart.
# Using the round roof object, size it to the appropriate dimension for the button hoop.
# Copy and paste<s>r</s> a second round roof object and make it slightly smaller to be used to create the hole for the button hoop.
# Turn the object into a hole and position it accordingly.
# Finally, group the shapes together and the button is completed.

== [[Digital technologies/3D printing/3D modeling- Intermediate/Design for 3D Printing|Design for 3D Printing]] ==
There are some important things to note when modeling for 3D printing. It is important to optimize the print by decreasing print time and material while ensuring accuracy and strength of the part.

# Divide your model into smaller more manageable parts. There are many designs with complex details or large dimensions that would be more manageable prints if split into multiple parts. [[File:Multiple parts 3D print.png|center|thumb|599x599px|3D printed hand built with multiple parts. Finger is attached afterwards. ]]
# Try to ensure that there is one flat surface on the print. This will allow easier print set-up. The flat side can adhere to the build plate, minimizing the need for additional build plate adhesion.[[File:Prints in different orientation.png|center|thumb|300x300px|Traffic cone printed in two different orientations. It demonstrates the optimal orientation with the least amount of supports. ]]
# Avoid floating parts. All aspect of the model should be connected to the main model. Minimize overhangs in the model as well. This will prevent wasted time and material to print supports.[[File:Supports under floating parts.png|center|thumb|480x480px|Printed gearbox with floating parts with supports under them. ]]
# FDM printing has limited capabilities with dimensional accuracy. It is recommended to prevent printing horizontally oriented holes of the smaller size. These holes are often deformed and printed with difficult to remove supports.[[File:Holes printed vertically and horizontally..png|center|thumb|500x500px|Holes printed vertically on the left and horizontally with the layers on the right. ]]
# Printed parts are stronger in one direction than another. It is important to keep this in mind when designing. Prints will be weaker in the areas where the layers meet. This means that printed parts have low tensile strength along the Z-axis. The prints will be the strongest in planes parallel to the build surface.[[File:Layers printed in different axis.png|center|thumb|500x500px]]
# Exaggerate the details of your designs. This is an important thing to keep in mind. In order for details to show up on small designs, you should make your cuts deeper and bigger. It can also be helpful to make slender designs thicker.[[File:Details on 3D prints.png|center|thumb|450x450px|Details on CAD on the left with the same details printed on the right. ]]
# Round surfaces will not show up smoothly. Since FDM prints in layers, it will cause the rounded surfaces to look jagged. To achieve a smooth surface, additional processing will be required. [[File:3D printed surface .png|center|thumb|449x449px|3D printed surface with all the layers before and after additional processing. ]]

If your design is to be used in (electro-)mechanical assemblies in which there are interfacing components, it is important that you understand three basic tolerancing concepts and to keep them in the back of your mind when modeling or more generally designing these assemblies.

# Form: The form of a part refers to the overall dimensions and the shape of the exterior surfaces of a component. Think of a flaw referring to form as a print that ended up not matching the base geometry that was used to create it in CAD due to adverse physical variables during the printing process. Examples follow:
## A ''sphere'' may end up slightly ''oval'' once printed due to improper cooling, etc.;
## A pillar might end up tilted to one side due to improper belt tension between the belt axes, etc.;
## A pin feature might end up too large to fit its mating hole due to the printer outputting too much material when producing the outer walls of the feature (the inverse can also be true).
# Position: Position refers to the distance separating a feature and an (ideally) meaningful reference (i.e.: the distance between a hole and the side of a part, or between two holes). Thankfully, flaws pertaining to position are rare on a properly tuned printer, as the printer does not have any information about existing references other than the build plate. If tuned properly, the printer will always print a feature at a position (X,Y,Z) distance relative to another feature, because that is what the gCode will tell it to do. You can imagine, however, that if the part is warped, the 'build plate reference' is no longer valid, and such, warped parts almost always have features out of position ''unless the meaningful reference (interfacing feature) used in the design is not the build plate''. However, since the build plate reference is such an important one to define the Z position of features (for the printer, that is), making your meaningful reference something other than the build plate does not always guarantee you good positional tolerance independent of warping.
# Surface: The surface finish of a part is a rather complex subject. In 3D printing, and for typical applications of 3D printed parts, it mostly refers to the mean (statistical) difference between the height of cusps and valleys on a part and their deviation from that mean, at a macroscopic level. The most important consideration is that when 3D printing, most surface finishes are quite rough (deviate significantly from the mean), and thus are sanded down considerably to knock out the cusps left by the printer. This post processing can negatively affect the form of the final part.

Note that ''a proper mechanical fit between components demands a good tolerance on form, feature position, and surface finish'', such that it is typically impossible to obtain a proper fit when 3D printing, and that if you are considering the 3D printing of critically interfacing components, 3D printing should not be used unless post processing ''is built into the design''. For mechanical designs, you will notice that a main application is brackets. This is because brackets only need good positional tolerance on holes and mating faces, which 3D printing can almost always provide (the tolerance on form for holes is not that important since they are typically clearance holes). However, since some brackets are easily laser cut, 3D printing brackets is only done under certain specific conditions. It certainly has shown its commercial use in cost cutting by replacing intricate multi-part assemblies by ''generatively designed'' (we'll say computer generated for now) parts, as shown in the picture below.
[[File:Design for 3D Printing Generatively Designed Bracket.jpg|center|thumb|600x600px|A metal 3D printed generatively designed bracket (computer generated from load data, using Finite Element Analysis), likely replacing a multitude of other parts that would have been manufactured using traditional manufacturing methods which would lead to a heavier and more expensive bracket.<ref>CarrusHome (2021). GM Explores 3D printing, generative design for next gen parts. Consulted on 05-05-2022 at <nowiki>https://www.carrushome.com/en/gm-explores-3d-printing-generative-design-for-next-gen-parts/</nowiki></ref>]]

==[[Digital technologies/3D printing/3D modeling- Intermediate/CAD Extensions|CAD File Formats]] ==
In the beginner section of 3D modeling, you were introduced to TinkerCAD. In the instructions, you were instructed to export your 3D designs as a STL or OBJ file. In this section, the differences between different CAD file formats will be discussed.

=== [https://en.wikipedia.org/wiki/STL_(file_format) Standard Triangle Language (*.STL)] ===
[[File:STL format.png|thumb|Facets used to represent a cube and a sphere.]]
[[File:Vector coordinates of STL format.png|thumb|305x305px|Visual representation of the vertices and the normal vector.]]
STL files are the most used file format in 3D printing and 3D modeling. Most 3D printers support the file format. Many of the 3D printable models online are also found in STL file format. STL stands for stereolithography, a 3D printing process created at 3D Systems in <ins>the </ins>1980s. STL file format encodes the surface geometry of a 3D object. This is done through tessellation, a process of tiling a surface with one or more geometric shapes so there are no overlaps or gaps. The basic method of tessellating the outer surface of 3D models is through the use of tiny triangles (called “facets”) and store information about the facets in a file. For example, in the figure below, it shows how a cube can be represented by 12 triangles while 17000+ triangles are needed to represent a sphere. Since triangles consist of three straight edges, it can be difficult to approximate curved geometries. To do so, mesh density is increased, and individual triangle’s size is decreased.

STL file format stores the information as the coordinates of the vertices and the components of the unit normal vector to the triangle. The normal vector point outwards of the 3D model.
[[File:STL tessellation .png|left|thumb|Invalid tessellation on the left, acceptable tessellation on the right]]
There are a couple of rules for tessellation and storing information. The vertex rule states that each triangle must share two vertices with its neighbouring triangles.

The orientation rule states that the orientation of the facet must be specified in two ways. The direction of the normal should point outwards, and the vertices are listed in counter-clockwise when looking at the object from the outside.

The all-positive octant rule states that the coordinates of the triangle vertices must all be positive. This ensures that all coordinates stored would be in the positive which would save space in the file. Finally, the triangle sorting rule recommends that the triangles appear in ascending z-value order. This is a recommendation rather than a rule as it helps the software slice the models faster.
[[File:STL orientation rule.png|center|thumb|525x525px|Visual representation of the orientation rule.]]

=== [https://en.wikipedia.org/wiki/Wavefront_.obj_file Wavefront OBJ (*.OBJ)] ===
OBJ is a crucial file format in 3D printing. It is generally preferred for multi-colour 3D printing. Often, it is used a s an interchange format for non-animated 3D models. OBJ file format stores information about 3D models by encoding the surface geometry of the model. It also stores information about its colour and texture. It does not store any data about animations or scene. It is open source and neutral. Therefore, it is often used to share 3D models since many CAD software supports the format.
[[File:OBJ file .png|thumb|Freeform curves on 3D model surface]]
It differs from STL since it stores colour and texture information. STL is an older file format that is missing modern features. It does not support multi colour printing or high resolution prints. OBJ can approximate surface geometry well without drastically increasing the file size. It also supports multiple colours and textures in the same model.

OBJ encodes surface geometry of a 3D object in many different methods: Tessellation with polygonal faces, freeform curves and freeform surfaces. Similar to STL, OBJ allows tessellation of the surfaces with simple geometric shapes like triangles or more complex polygon. This is the simplest way to describe surface geometry. However, approximating curved surfaces with polygons will introduce coarseness and geometric deviation from the model. The size of the polygons can be decreased to increase the quality of the prints. However, this can lead to giant file sizes which can be difficult for 3D printers to handle. It is important to find the right balance between print quality and file sizes.

The surface geometry can also be defined using freeform curves. The user defines a collection of free form curves that runs along the surface of the model. The surface is then approximated using the collection of curves. It is more complicated than polygonal faces, but it allows for fewer data to describe the same surface. The curved lines can be described using freeform curves with a few mathematical parameters. It allows for higher quality encoding without drastically increasing the file size.

=== DS Solidworks Parts (*.SLDPRT) and DS Solidworks Assemblies (*.SLDASM) ===
Sldprt file formats are native SolidWorks file extensions. It provides details on specific parts within a system. This is a software specific file format. Opening SolidWorks files in slicers and other software may cause some corruption of your designs. However, because it is software specific, it contains the most information about your models. As such, you should do all your modeling while the files are in native format

=== [https://en.wikipedia.org/wiki/ISO_10303 ISO10303 - Standard for the Exchange of Product model data (*.STP, *.STEP)] ===
STEP file format is a neutral file format. It is the most common file format used to share 3D designs. This allows users to open others’ designs using the software of their choice. It stores 3D images in an ASCII format. While STEP files can be opened with most CAD software. It is not easily edited. The model will display as a finalized object. Users cannot edit specific dimensions or features of the model.

===Polygonal Formats===

*[https://en.wikipedia.org/wiki/STL_(file_format) Standard Triangle Language (*.STL)]
*[https://en.wikipedia.org/wiki/Wavefront_.obj_file Wavefront OBJ (*.OBJ)]
*[https://en.wikipedia.org/wiki/3D_Manufacturing_Format 3D Manufacturing Format (*.3MF)]

===NURBS Formats===

====Standard====

*[https://en.wikipedia.org/wiki/ISO_10303 ISO10303 - Standard for the Exchange of Product model data (*.STP, *.STEP)]
*[https://en.wikipedia.org/wiki/AutoCAD_DXF AutoCAD Drawing Exchange Format (*.DXF/*.DWG)]
*[https://en.wikipedia.org/wiki/IGES Initial Graphics Exchange Specification (*.IGES)] (standard last updated 1996)

====Software-Specific====

*DS Solidworks Parts (*.SLDPRT)
*DS Solidworks Assemblies (*.SLDASM)
*DS CATIA V5 Parts (*.CGR/*.CATPart)
*DS CATIA V5 Assemblies (*.CGR/*.CATProduct)
*PTC Creo Parts (*.PRT)
*PTC Creo Assemblies (*.ASM)

*Fusion 360 (*.F3D)

It should be noted that Fusion360 stores files on the cloud, such that locally saved .f3d files are not commonly encountered. It should also be noted that OnShape does not have a file format given it is hosted entirely on the cloud.

==[[Digital technologies/3D printing/3D modeling- Intermediate/Using Parametric NURBS Software|Introduction to Fusion360]]==
TinkerCAD is known for its simplicity, meaning it is easy to learn and use. However, its capabilities are limited. It uses a drag and drop method to create basic geometries. Theses shapes can be grouped to create more complex geometries but it takes more time to design something complex and has less flexibility. Fusion<ins> </ins>360 is a sketch-based CAD modeling software that allows for users to completely customize their design. It allows users to design 3D objects using 2D sketches.

Fusion 360 offers 3D CAD modeling, PCB design, and 3D simulation capabilities. It is a fee-based subscription software, however, a free version is offered for personal use. The free version has some limited capabilities but most of the 3D CAD features are offered. Even with the limited features it offers more design options than TinkerCAD. To download the software, you can use your AutoCAD account and follow the link below: <nowiki>https://www.autodesk.ca/en/products/fusion-360/personal</nowiki>

Just like TinkerCAD, and with any CAD modeling software you choose to use<ins>,</ins><s>. Y</s><ins> y</ins>ou can export your part designs as an STL file. Using this file format, you can use any slicer of your choice to slice the design into a gcode file to print.

=== Fusion 360 User Interface ===
[[File:User Interface of Fusion 360.png|center|959x959px]]
There are 5 main areas of the user interface. When the software is first launched, you should be seeing the screen above.

# Data Panel: On the left is the data panel. It displays pinned and recent projects, providing easy access to these projects for the users. It will also display sample projects that corresponds to the tutorials offered by AutoCAD. Users can also upload their projects to be shared with others for collaboration.
# Tool Bar: On the top of the screen sits the tool bar. Through this, you can use any of the features displayed to manipulate the 3D model you create. The shortcuts can be customized to display the ones you favour.
# Browser: Located at the top left of the main screen. It displays the model design with a file tree structure listing all the components, bodies and constructing plane. The files can be navigated through by clicking on their names. They can also be renamed by double clicking. The files can be collapsed using the triangles. The visibility of the bodies and planes can be toggled by clicking on the lightbulb.
# Timeline: The timeline of the design history is displayed at the bottom of the screen. This is a special feature of Fusion<ins> </ins>360 that is different from other CAD software. It keeps a record of the construction of the 3D model allowing the users to playback the building of the model. This feature also allow<ins>s</ins> users to add to the model from a previous state of the model.
# Navigation bar: The navigation bard allows users to change the view of the model. These features exist<s>s</s> as shortcuts when used with a mouse. For this reason, it is recommended to create CAD models using a physical mouse instead of a track pad. Some features include:
#* Zoom In/Out by scrolling up/down with the mouse.
#* Pan the model by holding down the wheel of the mouse.
#* Orbit the model by holding down control + wheel.

=== Sketching ===
The sketch function is the most important feature of a CAD program. It allows users to sketch 2D drawings as the base to create 3D objects.
[[File:Sketch Interface.png|center|650x650px]]
To create a rectangle, first click on “Create Sketch” from the tool bar above. Select the desired sketch plane. In the example above, YZ plane was selected. This is the plane which the 2D sketch will be created. You’ll notice the tool bar above has transformed to display sketch functions. Select “2-Point Rectangle” from the tool bar. Click on the origin of the sketch plane and drag to create a desired rectangle. The sketch features are defined with reference to the origin to position it in space. It is why it is recommended to have one vertex of the sketch to be defined as the origin. After the rectangle is drawn, you can define the dimensions of the 2 sides of the rectangle. You can toggle between the dimensions by using the “Tab” key on your keyboard. Press enter to confirm the sketch.
[[File:Fusion 360 Rectangle Sketch.png|center|600x600px]]
Next, the line tool will be introduced. Drawing a line is the most simple and versatile function of sketch. It will allow you to create any shapes you will need. Select the “Line” option from the tool bar. Hover your mouse over the rectangle, the mouse will be drawn to the line and an ‘X’ will appear. This means that one end of the line will intersect with the rectangle. Move the mouse towards the middle of the line on the rectangle until a triangle icon shows up. This signifies the midpoint of the line. Click to create the start of the line segment. Drag the mouse to create the line and click again to create the end of the line. You can also manipulate the dimension of the line manually by entering the value.
[[File:Fusion 360 Line Sketch.png|center|649x649px]]
To draw the line at an angle, drag the line out at an angle. At this point, there should be an angle dimension displayed. This value can be altered manually.

To create an arc, select “Create” -> “Arc” -> “Tangent Arc” from the tool bar. This will create an arc tangent to two other entities. Left click on the vertex of where you would like the arc to connect. Then click on the other vertex to connect. Alternative to create arcs include 3-point arcs where you select the two vertex and the middle point of the arc or center point arc when the arc is create<ins>d</ins> by finding the center of the arc.
[[File:Arc Sketch.png|center|648x648px]]

In order for a 2D sketch to be converted to 3D model, the 2D profile has to be a closed shape. This means all the lines and entities have to form a closed loop. This will be indicated with a light-blue shading inside the sketch.

=== Extrusion ===
The simplest way to create a 3D model is by extruding a 2D sketch, which adds a third dimension to the 2D sketch. Select “Extrude” from the toolbar. Hover the mouse over the sketch, closed shapes that can be extruded will be highlighted when hovered on. To select multiple shapes, left click on both shapes. In the extrusion settings that pops up on the right, enter the value for the third dimension of the sketch, the width. Click “OK” to confirm the extrusion.
[[File:Extrusion example.png|center|650x650px]]
You can select a new surface from the extruded object to sketch on. To do so, select “Create Sketch” and select the surface you would like to sketch on as the plane. Afterwards continue to sketch like normal.

Extrusion can also be used to cut. Sketch on the surface of the shape the geometry you would like to cut. Select “Extrude” tool and select the shapes you would like to cut. To remove material, enter a negative value in the dimension window. This indicates the direction you would like the extrusion to occur. On the screen, it will display a red region to indicate material removal. Press enter to confirm the operation.
[[File:Extrusion cut example.png|center|650x650px]]

=== Mirror ===
The mirror tool is an extremely powerful tool that can save the user a lot of time in creating the 3D models. This is especially useful when creating symmetrical objects. It allows users to mirror solid or small features. It does require the user to define the plane to mirror the features. There are many ways to create the plane. One of which is to “Offset Plane”
[[File:Mirror Example.png|center|650x650px]]

Under the “Construct” drop-down menu from the toolbar, select “Offset Plane”. Select a surface to offset from. This surface should be parallel from the plane you would like to create. Now enter the dimension you would like to offset the plane from the surface. Press enter when completed.

After the plane has been created, you can now mirror the features. Select “Mirror” under the drop<ins>-</ins> down menu from “Create” from the toolbar. Under “Type” parameter, you can select bodies, faces, features, or components. After the type has been selected, click on “Select” by Object and then the features you would like to mirror, you can also click on the features from the design history timeline. Then click on “Select” by Mirror Plane and the plane you would to mirror from. Now a preview will be displayed<ins>,</ins> to confirm press enter.

=== Fillet ===
Filleting the edges is a feature that is offered in Fusion 360 and not TinkerCAD. It can easily elevate your models. It creates rounded surfaces by adding or removing from a solid model.
[[File:Fillet Example.png|center|650x650px]]

# Select “Fillet” under the modify menu from the tool bar.
# Click on the edges you would like to round out.
# Enter a radius value to round the edges out to.
# Click “OK” to finalize.

== References ==
<references />

Digital technologies/3D printing/3D modeling- Intermediate

2023-08-25T19:27:00Z

Cecilial:

TinkerCAD is nice for smaller parts with very little complexity. However, since it is not [https://en.wikipedia.org/wiki/Non-uniform_rational_B-spline NURBS] based nor parametric, it lacks major functionality. It is strongly suggested at this stage that TinkerCAD, Blender, Cinema 4D or other [https://en.wikipedia.org/wiki/Polygonal_modeling polygonal modelling] (non-NURBS) applications be set aside for parametric CAD software, such as [https://www.autodesk.ca/en/products/fusion-360 Autodesk Fusion 360] ([https://www.autodesk.ca/en/products/fusion-360/students-teachers-educators free for students. teachers, and educators]), [https://www.solidworks.com/ Dassault Systèmes Solidworks] (available through Remote Apps) or [https://www.onshape.com/en/ PTC OnShape] (completely online, free for students and educators) be used for mechanical design, as models made with such software contain much richer data that allows going from CAD models to manufacturing data. Polygonal modelling remains, however, an important tool for Scan to CAD, and such the intermediate CAD user should have a complete understanding of polygonal modelling software such as TinkerCAD.

==[[Digital technologies/3D printing/3D modeling- Intermediate/TinkerCAD (contd.)|Complex Shapes in TinkerCAD]]==
[[File:Heart Button TinkerCAD.png|left|thumb|Heart button CAD model|200x200px]]
In the beginner section of 3D modeling, you learned how to group shapes together. In advanced TinkerCAD, you will use the skills you have gained to create more complex shapes. TinkerCAD provides you with basic geometries such as cubes and cylinders. You can combine these shapes to create more complex geometries such as a house using the group function. To create even more complicated designs, you can combine shapes to be used to create complex holes

<youtube>kVXkdLfK1kw</youtube>

The example below will walk you through the making of a heart button. It will involve grouping shapes together in order to create a more complex shape and feature
[[File:Heart_Button_Construction.png|alt=|thumb|351x351px|Combining simple shapes like cylinders and cubes to create heart shape. ]]
# Add a box shape to the workspace. Make sure the dimension of the box has the thickness of the desired button. This will serve as the point of the heart.
# Add two cylinders with the same thickness as the box to two edges of the box. Set the diameter of the cylinder as the width of the box. This will create the humps of the heart.
# Using the round roof object, size it to the appropriate dimension for the button hoop.
# Copy and paste<s>r</s> a second round roof object and make it slightly smaller to be used to create the hole for the button hoop.
# Turn the object into a hole and position it accordingly.
# Finally, group the shapes together and the button is completed.

== [[Digital technologies/3D printing/3D modeling- Intermediate/Design for 3D Printing|Design for 3D Printing]] ==
There are some important things to note when modeling for 3D printing. It is important to optimize the print by decreasing print time and material while ensuring accuracy and strength of the part.

# Divide your model into smaller more manageable parts. There are many designs with complex details or large dimensions that would be more manageable prints if split into multiple parts. [[File:Multiple parts 3D print.png|center|thumb|599x599px|3D printed hand built with multiple parts. Finger is attached afterwards. ]]
# Try to ensure that there is one flat surface on the print. This will allow easier print set-up. The flat side can adhere to the build plate, minimizing the need for additional build plate adhesion.[[File:Prints in different orientation.png|center|thumb|300x300px|Traffic cone printed in two different orientations. It demonstrates the optimal orientation with the least amount of supports. ]]
# Avoid floating parts. All aspect of the model should be connected to the main model. Minimize overhangs in the model as well. This will prevent wasted time and material to print supports.[[File:Supports under floating parts.png|center|thumb|480x480px|Printed gearbox with floating parts with supports under them. ]]
# FDM printing has limited capabilities with dimensional accuracy. It is recommended to prevent printing horizontally oriented holes of the smaller size. These holes are often deformed and printed with difficult to remove supports.[[File:Holes printed vertically and horizontally..png|center|thumb|500x500px|Holes printed vertically on the left and horizontally with the layers on the right. ]]
# Printed parts are stronger in one direction than another. It is important to keep this in mind when designing. Prints will be weaker in the areas where the layers meet. This means that printed parts have low tensile strength along the Z-axis. The prints will be the strongest in planes parallel to the build surface.[[File:Layers printed in different axis.png|center|thumb|500x500px]]
# Exaggerate the details of your designs. This is an important thing to keep in mind. In order for details to show up on small designs, you should make your cuts deeper and bigger. It can also be helpful to make slender designs thicker.[[File:Details on 3D prints.png|center|thumb|450x450px|Details on CAD on the left with the same details printed on the right. ]]
# Round surfaces will not show up smoothly. Since FDM prints in layers, it will cause the rounded surfaces to look jagged. To achieve a smooth surface, additional processing will be required. [[File:3D printed surface .png|center|thumb|449x449px|3D printed surface with all the layers before and after additional processing. ]]

If your design is to be used in (electro-)mechanical assemblies in which there are interfacing components, it is important that you understand three basic tolerancing concepts and to keep them in the back of your mind when modeling or more generally designing these assemblies.

# Form: The form of a part refers to the overall dimensions and the shape of the exterior surfaces of a component. Think of a flaw referring to form as a print that ended up not matching the base geometry that was used to create it in CAD due to adverse physical variables during the printing process. Examples follow:
## A ''sphere'' may end up slightly ''oval'' once printed due to improper cooling, etc.;
## A pillar might end up tilted to one side due to improper belt tension between the belt axes, etc.;
## A pin feature might end up too large to fit its mating hole due to the printer outputting too much material when producing the outer walls of the feature (the inverse can also be true).
# Position: Position refers to the distance separating a feature and an (ideally) meaningful reference (i.e.: the distance between a hole and the side of a part, or between two holes). Thankfully, flaws pertaining to position are rare on a properly tuned printer, as the printer does not have any information about existing references other than the build plate. If tuned properly, the printer will always print a feature at a position (X,Y,Z) distance relative to another feature, because that is what the gCode will tell it to do. You can imagine, however, that if the part is warped, the 'build plate reference' is no longer valid, and such, warped parts almost always have features out of position ''unless the meaningful reference (interfacing feature) used in the design is not the build plate''. However, since the build plate reference is such an important one to define the Z position of features (for the printer, that is), making your meaningful reference something other than the build plate does not always guarantee you good positional tolerance independent of warping.
# Surface: The surface finish of a part is a rather complex subject. In 3D printing, and for typical applications of 3D printed parts, it mostly refers to the mean (statistical) difference between the height of cusps and valleys on a part and their deviation from that mean, at a macroscopic level. The most important consideration is that when 3D printing, most surface finishes are quite rough (deviate significantly from the mean), and thus are sanded down considerably to knock out the cusps left by the printer. This post processing can negatively affect the form of the final part.

Note that ''a proper mechanical fit between components demands a good tolerance on form, feature position, and surface finish'', such that it is typically impossible to obtain a proper fit when 3D printing, and that if you are considering the 3D printing of critically interfacing components, 3D printing should not be used unless post processing ''is built into the design''. For mechanical designs, you will notice that a main application is brackets. This is because brackets only need good positional tolerance on holes and mating faces, which 3D printing can almost always provide (the tolerance on form for holes is not that important since they are typically clearance holes). However, since some brackets are easily laser cut, 3D printing brackets is only done under certain specific conditions. It certainly has shown its commercial use in cost cutting by replacing intricate multi-part assemblies by ''generatively designed'' (we'll say computer generated for now) parts, as shown in the picture below.
[[File:Design for 3D Printing Generatively Designed Bracket.jpg|center|thumb|600x600px|A metal 3D printed generatively designed bracket (computer generated from load data, using Finite Element Analysis), likely replacing a multitude of other parts that would have been manufactured using traditional manufacturing methods which would lead to a heavier and more expensive bracket.<ref>CarrusHome (2021). GM Explores 3D printing, generative design for next gen parts. Consulted on 05-05-2022 at <nowiki>https://www.carrushome.com/en/gm-explores-3d-printing-generative-design-for-next-gen-parts/</nowiki></ref>]]

==[[Digital technologies/3D printing/3D modeling- Intermediate/CAD Extensions|CAD File Formats]] ==
In the beginner section of 3D modeling, you were introduced to TinkerCAD. In the instructions, you were instructed to export your 3D designs as a STL or OBJ file. In this section, the differences between different CAD file formats will be discussed.

=== [https://en.wikipedia.org/wiki/STL_(file_format) Standard Triangle Language (*.STL)] ===
[[File:STL format.png|thumb|Facets used to represent a cube and a sphere.]]
[[File:Vector coordinates of STL format.png|thumb|305x305px|Visual representation of the vertices and the normal vector.]]
STL files are the most used file format in 3D printing and 3D modeling. Most 3D printers support the file format. Many of the 3D printable models online are also found in STL file format. STL stands for stereolithography, a 3D printing process created at 3D Systems in <ins>the </ins>1980s. STL file format encodes the surface geometry of a 3D object. This is done through tessellation, a process of tiling a surface with one or more geometric shapes so there are no overlaps or gaps. The basic method of tessellating the outer surface of 3D models is through the use of tiny triangles (called “facets”) and store information about the facets in a file. For example, in the figure below, it shows how a cube can be represented by 12 triangles while 17000+ triangles are needed to represent a sphere. Since triangles consist of three straight edges, it can be difficult to approximate curved geometries. To do so, mesh density is increased, and individual triangle’s size is decreased.

STL file format stores the information as the coordinates of the vertices and the components of the unit normal vector to the triangle. The normal vector point outwards of the 3D model.
[[File:STL tessellation .png|left|thumb|Invalid tessellation on the left, acceptable tessellation on the right]]
There are a couple of rules for tessellation and storing information. The vertex rule states that each triangle must share two vertices with its neighbouring triangles.

The orientation rule states that the orientation of the facet must be specified in two ways. The direction of the normal should point outwards, and the vertices are listed in counter-clockwise when looking at the object from the outside.

The all-positive octant rule states that the coordinates of the triangle vertices must all be positive. This ensures that all coordinates stored would be in the positive which would save space in the file. Finally, the triangle sorting rule recommends that the triangles appear in ascending z-value order. This is a recommendation rather than a rule as it helps the software slice the models faster.
[[File:STL orientation rule.png|center|thumb|525x525px|Visual representation of the orientation rule.]]

=== [https://en.wikipedia.org/wiki/Wavefront_.obj_file Wavefront OBJ (*.OBJ)] ===
OBJ is a crucial file format in 3D printing. It is generally preferred for multi-colour 3D printing. Often, it is used a s an interchange format for non-animated 3D models. OBJ file format stores information about 3D models by encoding the surface geometry of the model. It also stores information about its colour and texture. It does not store any data about animations or scene. It is open source and neutral. Therefore, it is often used to share 3D models since many CAD software supports the format.
[[File:OBJ file .png|thumb|Freeform curves on 3D model surface]]
It differs from STL since it stores colour and texture information. STL is an older file format that is missing modern features. It does not support multi colour printing or high resolution prints. OBJ can approximate surface geometry well without drastically increasing the file size. It also supports multiple colours and textures in the same model.

OBJ encodes surface geometry of a 3D object in many different methods: Tessellation with polygonal faces, freeform curves and freeform surfaces. Similar to STL, OBJ allows tessellation of the surfaces with simple geometric shapes like triangles or more complex polygon. This is the simplest way to describe surface geometry. However, approximating curved surfaces with polygons will introduce coarseness and geometric deviation from the model. The size of the polygons can be decreased to increase the quality of the prints. However, this can lead to giant file sizes which can be difficult for 3D printers to handle. It is important to find the right balance between print quality and file sizes.

The surface geometry can also be defined using freeform curves. The user defines a collection of free form curves that runs along the surface of the model. The surface is then approximated using the collection of curves. It is more complicated than polygonal faces, but it allows for fewer data to describe the same surface. The curved lines can be described using freeform curves with a few mathematical parameters. It allows for higher quality encoding without drastically increasing the file size.

=== DS Solidworks Parts (*.SLDPRT) and DS Solidworks Assemblies (*.SLDASM) ===
Sldprt file formats are native SolidWorks file extensions. It provides details on specific parts within a system. This is a software specific file format. Opening SolidWorks files in slicers and other software may cause some corruption of your designs. However, because it is software specific, it contains the most information about your models. As such, you should do all your modeling while the files are in native format

=== [https://en.wikipedia.org/wiki/ISO_10303 ISO10303 - Standard for the Exchange of Product model data (*.STP, *.STEP)] ===
STEP file format is a neutral file format. It is the most common file format used to share 3D designs. This allows users to open others’ designs using the software of their choice. It stores 3D images in an ASCII format. While STEP files can be opened with most CAD software. It is not easily edited. The model will display as a finalized object. Users cannot edit specific dimensions or features of the model.

===Polygonal Formats===

*[https://en.wikipedia.org/wiki/STL_(file_format) Standard Triangle Language (*.STL)]
*[https://en.wikipedia.org/wiki/Wavefront_.obj_file Wavefront OBJ (*.OBJ)]
*[https://en.wikipedia.org/wiki/3D_Manufacturing_Format 3D Manufacturing Format (*.3MF)]

===NURBS Formats===

====Standard====

*[https://en.wikipedia.org/wiki/ISO_10303 ISO10303 - Standard for the Exchange of Product model data (*.STP, *.STEP)]
*[https://en.wikipedia.org/wiki/AutoCAD_DXF AutoCAD Drawing Exchange Format (*.DXF/*.DWG)]
*[https://en.wikipedia.org/wiki/IGES Initial Graphics Exchange Specification (*.IGES)] (standard last updated 1996)

====Software-Specific====

*DS Solidworks Parts (*.SLDPRT)
*DS Solidworks Assemblies (*.SLDASM)
*DS CATIA V5 Parts (*.CGR/*.CATPart)
*DS CATIA V5 Assemblies (*.CGR/*.CATProduct)
*PTC Creo Parts (*.PRT)
*PTC Creo Assemblies (*.ASM)

*Fusion 360 (*.F3D)

It should be noted that Fusion360 stores files on the cloud, such that locally saved .f3d files are not commonly encountered. It should also be noted that OnShape does not have a file format given it is hosted entirely on the cloud.

==[[Digital technologies/3D printing/3D modeling- Intermediate/Using Parametric NURBS Software|Introduction to Fusion360]]==
TinkerCAD is known for its simplicity, meaning it is easy to learn and use. However, its capabilities are limited. It uses a drag and drop method to create basic geometries. Theses shapes can be grouped to create more complex geometries but it takes more time to design something complex and has less flexibility. Fusion<ins> </ins>360 is a sketch-based CAD modeling software that allows for users to completely customize their design. It allows users to design 3D objects using 2D sketches.

Fusion 360 offers 3D CAD modeling, PCB design, and 3D simulation capabilities. It is a fee-based subscription software, however, a free version is offered for personal use. The free version has some limited capabilities but most of the 3D CAD features are offered. Even with the limited features it offers more design options than TinkerCAD. To download the software, you can use your AutoCAD account and follow the link below: <nowiki>https://www.autodesk.ca/en/products/fusion-360/personal</nowiki>

Just like TinkerCAD, and with any CAD modeling software you choose to use<ins>,</ins><s>. Y</s><ins> y</ins>ou can export your part designs as an STL file. Using this file format, you can use any slicer of your choice to slice the design into a gcode file to print.

=== Fusion 360 User Interface ===
[[File:User Interface of Fusion 360.png|center|959x959px]]
There are 5 main areas of the user interface. When the software is first launched, you should be seeing the screen above.

# Data Panel: On the left is the data panel. It displays pinned and recent projects, providing easy access to these projects for the users. It will also display sample projects that corresponds to the tutorials offered by AutoCAD. Users can also upload their projects to be shared with others for collaboration.
# Tool Bar: On the top of the screen sits the tool bar. Through this, you can use any of the features displayed to manipulate the 3D model you create. The shortcuts can be customized to display the ones you favour.
# Browser: Located at the top left of the main screen. It displays the model design with a file tree structure listing all the components, bodies and constructing plane. The files can be navigated through by clicking on their names. They can also be renamed by double clicking. The files can be collapsed using the triangles. The visibility of the bodies and planes can be toggled by clicking on the lightbulb.
# Timeline: The timeline of the design history is displayed at the bottom of the screen. This is a special feature of Fusion<ins> </ins>360 that is different from other CAD software. It keeps a record of the construction of the 3D model allowing the users to playback the building of the model. This feature also allow<ins>s</ins> users to add to the model from a previous state of the model.
# Navigation bar: The navigation bard allows users to change the view of the model. These features exist<s>s</s> as shortcuts when used with a mouse. For this reason, it is recommended to create CAD models using a physical mouse instead of a track pad. Some features include:
#* Zoom In/Out by scrolling up/down with the mouse.
#* Pan the model by holding down the wheel of the mouse.
#* Orbit the model by holding down control + wheel.

=== Sketching ===
The sketch function is the most important feature of a CAD program. It allows users to sketch 2D drawings as the base to create 3D objects.
[[File:Sketch Interface.png|center|650x650px]]
To create a rectangle, first click on “Create Sketch” from the tool bar above. Select the desired sketch plane. In the example above, YZ plane was selected. This is the plane which the 2D sketch will be created. You’ll notice the tool bar above has transformed to display sketch functions. Select “2-Point Rectangle” from the tool bar. Click on the origin of the sketch plane and drag to create a desired rectangle. The sketch features are defined with reference to the origin to position it in space. It is why it is recommended to have one vertex of the sketch to be defined as the origin. After the rectangle is drawn, you can define the dimensions of the 2 sides of the rectangle. You can toggle between the dimensions by using the “Tab” key on your keyboard. Press enter to confirm the sketch.
[[File:Fusion 360 Rectangle Sketch.png|center|600x600px]]
Next, the line tool will be introduced. Drawing a line is the most simple and versatile function of sketch. It will allow you to create any shapes you will need. Select the “Line” option from the tool bar. Hover your mouse over the rectangle, the mouse will be drawn to the line and an ‘X’ will appear. This means that one end of the line will intersect with the rectangle. Move the mouse towards the middle of the line on the rectangle until a triangle icon shows up. This signifies the midpoint of the line. Click to create the start of the line segment. Drag the mouse to create the line and click again to create the end of the line. You can also manipulate the dimension of the line manually by entering the value.
[[File:Fusion 360 Line Sketch.png|center|649x649px]]
To draw the line at an angle, drag the line out at an angle. At this point, there should be an angle dimension displayed. This value can be altered manually.

To create an arc, select “Create” -> “Arc” -> “Tangent Arc” from the tool bar. This will create an arc tangent to two other entities. Left click on the vertex of where you would like the arc to connect. Then click on the other vertex to connect. Alternative to create arcs include 3-point arcs where you select the two vertex and the middle point of the arc or center point arc when the arc is create<ins>d</ins> by finding the center of the arc.
[[File:Arc Sketch.png|center|648x648px]]

In order for a 2D sketch to be converted to 3D model, the 2D profile has to be a closed shape. This means all the lines and entities have to form a closed loop. This will be indicated with a light-blue shading inside the sketch.

=== Extrusion ===
The simplest way to create a 3D model is by extruding a 2D sketch, which adds a third dimension to the 2D sketch. Select “Extrude” from the toolbar. Hover the mouse over the sketch, closed shapes that can be extruded will be highlighted when hovered on. To select multiple shapes, left click on both shapes. In the extrusion settings that pops up on the right, enter the value for the third dimension of the sketch, the width. Click “OK” to confirm the extrusion.
[[File:Extrusion example.png|center|650x650px]]
You can select a new surface from the extruded object to sketch on. To do so, select “Create Sketch” and select the surface you would like to sketch on as the plane. Afterwards continue to sketch like normal.

Extrusion can also be used to cut. Sketch on the surface of the shape the geometry you would like to cut. Select “Extrude” tool and select the shapes you would like to cut. To remove material, enter a negative value in the dimension window. This indicates the direction you would like the extrusion to occur. On the screen, it will display a red region to indicate material removal. Press enter to confirm the operation.
[[File:Extrusion cut example.png|center|650x650px]]

=== Mirror ===
The mirror tool is an extremely powerful tool that can save the user a lot of time in creating the 3D models. This is especially useful when creating symmetrical objects. It allows users to mirror solid or small features. It does require the user to define the plane to mirror the features. There are many ways to create the plane. One of which is to “Offset Plane”
[[File:Mirror Example.png|center|650x650px]]

Under the “Construct” drop-down menu from the toolbar, select “Offset Plane”. Select a surface to offset from. This surface should be parallel from the plane you would like to create. Now enter the dimension you would like to offset the plane from the surface. Press enter when completed.

After the plane has been created, you can now mirror the features. Select “Mirror” under the drop<ins>-</ins> down menu from “Create” from the toolbar. Under “Type” parameter, you can select bodies, faces, features, or components. After the type has been selected, click on “Select” by Object and then the features you would like to mirror, you can also click on the features from the design history timeline. Then click on “Select” by Mirror Plane and the plane you would to mirror from. Now a preview will be displayed<ins>,</ins> to confirm press enter.

=== Fillet ===
Filleting the edges is a feature that is offered in Fusion 360 and not TinkerCAD. It can easily elevate your models. It creates rounded surfaces by adding or removing from a solid model.
[[File:Fillet Example.png|center|650x650px]]

# Select “Fillet” under the modify menu from the tool bar.
# Click on the edges you would like to round out.
# Enter a radius value to round the edges out to.
# Click “OK” to finalize.

== References ==
<references />

Digital technologies/3D printing/3D modeling- Intermediate

2023-08-25T19:24:56Z

Cecilial: /* Sketching */

TinkerCAD is nice for smaller parts with very little complexity. However, since it is not [https://en.wikipedia.org/wiki/Non-uniform_rational_B-spline NURBS] based nor parametric, it lacks major functionality. It is strongly suggested at this stage that TinkerCAD, Blender, Cinema 4D or other [https://en.wikipedia.org/wiki/Polygonal_modeling polygonal modelling] (non-NURBS) applications be set aside for parametric CAD software, such as [https://www.autodesk.ca/en/products/fusion-360 Autodesk Fusion 360] ([https://www.autodesk.ca/en/products/fusion-360/students-teachers-educators free for students. teachers, and educators]), [https://www.solidworks.com/ Dassault Systèmes Solidworks] (available through Remote Apps) or [https://www.onshape.com/en/ PTC OnShape] (completely online, free for students and educators) be used for mechanical design, as models made with such software contain much richer data that allows going from CAD models to manufacturing data. Polygonal modelling remains, however, an important tool for Scan to CAD, and such the intermediate CAD user should have a complete understanding of polygonal modelling software such as TinkerCAD.

==[[Digital technologies/3D printing/3D modeling- Intermediate/TinkerCAD (contd.)|Complex Shapes in TinkerCAD]]==
[[File:Heart Button TinkerCAD.png|left|thumb|Heart button CAD model|200x200px]]
In the beginner section of 3D modeling, you learned how to group shapes together. In advanced TinkerCAD, you will use the skills you have gained to create more complex shapes. TinkerCAD provides you with basic geometries such as cubes and cylinders. You can combine these shapes to create more complex geometries such as a house using the group function. To create even more complicated designs, you can combine shapes to be used to create complex holes

The example below will walk you through the making of a heart button. It will involve grouping shapes together in order to create a more complex shape and feature
[[File:Heart_Button_Construction.png|alt=|thumb|351x351px|Combining simple shapes like cylinders and cubes to create heart shape. ]]
# Add a box shape to the workspace. Make sure the dimension of the box has the thickness of the desired button. This will serve as the point of the heart.
# Add two cylinders with the same thickness as the box to two edges of the box. Set the diameter of the cylinder as the width of the box. This will create the humps of the heart.
# Using the round roof object, size it to the appropriate dimension for the button hoop.
# Copy and paste<s>r</s> a second round roof object and make it slightly smaller to be used to create the hole for the button hoop.
# Turn the object into a hole and position it accordingly.
# Finally, group the shapes together and the button is completed.

== [[Digital technologies/3D printing/3D modeling- Intermediate/Design for 3D Printing|Design for 3D Printing]] ==
There are some important things to note when modeling for 3D printing. It is important to optimize the print by decreasing print time and material while ensuring accuracy and strength of the part.

# Divide your model into smaller more manageable parts. There are many designs with complex details or large dimensions that would be more manageable prints if split into multiple parts. [[File:Multiple parts 3D print.png|center|thumb|599x599px|3D printed hand built with multiple parts. Finger is attached afterwards. ]]
# Try to ensure that there is one flat surface on the print. This will allow easier print set-up. The flat side can adhere to the build plate, minimizing the need for additional build plate adhesion.[[File:Prints in different orientation.png|center|thumb|300x300px|Traffic cone printed in two different orientations. It demonstrates the optimal orientation with the least amount of supports. ]]
# Avoid floating parts. All aspect of the model should be connected to the main model. Minimize overhangs in the model as well. This will prevent wasted time and material to print supports.[[File:Supports under floating parts.png|center|thumb|480x480px|Printed gearbox with floating parts with supports under them. ]]
# FDM printing has limited capabilities with dimensional accuracy. It is recommended to prevent printing horizontally oriented holes of the smaller size. These holes are often deformed and printed with difficult to remove supports.[[File:Holes printed vertically and horizontally..png|center|thumb|500x500px|Holes printed vertically on the left and horizontally with the layers on the right. ]]
# Printed parts are stronger in one direction than another. It is important to keep this in mind when designing. Prints will be weaker in the areas where the layers meet. This means that printed parts have low tensile strength along the Z-axis. The prints will be the strongest in planes parallel to the build surface.[[File:Layers printed in different axis.png|center|thumb|500x500px]]
# Exaggerate the details of your designs. This is an important thing to keep in mind. In order for details to show up on small designs, you should make your cuts deeper and bigger. It can also be helpful to make slender designs thicker.[[File:Details on 3D prints.png|center|thumb|450x450px|Details on CAD on the left with the same details printed on the right. ]]
# Round surfaces will not show up smoothly. Since FDM prints in layers, it will cause the rounded surfaces to look jagged. To achieve a smooth surface, additional processing will be required. [[File:3D printed surface .png|center|thumb|449x449px|3D printed surface with all the layers before and after additional processing. ]]

If your design is to be used in (electro-)mechanical assemblies in which there are interfacing components, it is important that you understand three basic tolerancing concepts and to keep them in the back of your mind when modeling or more generally designing these assemblies.

# Form: The form of a part refers to the overall dimensions and the shape of the exterior surfaces of a component. Think of a flaw referring to form as a print that ended up not matching the base geometry that was used to create it in CAD due to adverse physical variables during the printing process. Examples follow:
## A ''sphere'' may end up slightly ''oval'' once printed due to improper cooling, etc.;
## A pillar might end up tilted to one side due to improper belt tension between the belt axes, etc.;
## A pin feature might end up too large to fit its mating hole due to the printer outputting too much material when producing the outer walls of the feature (the inverse can also be true).
# Position: Position refers to the distance separating a feature and an (ideally) meaningful reference (i.e.: the distance between a hole and the side of a part, or between two holes). Thankfully, flaws pertaining to position are rare on a properly tuned printer, as the printer does not have any information about existing references other than the build plate. If tuned properly, the printer will always print a feature at a position (X,Y,Z) distance relative to another feature, because that is what the gCode will tell it to do. You can imagine, however, that if the part is warped, the 'build plate reference' is no longer valid, and such, warped parts almost always have features out of position ''unless the meaningful reference (interfacing feature) used in the design is not the build plate''. However, since the build plate reference is such an important one to define the Z position of features (for the printer, that is), making your meaningful reference something other than the build plate does not always guarantee you good positional tolerance independent of warping.
# Surface: The surface finish of a part is a rather complex subject. In 3D printing, and for typical applications of 3D printed parts, it mostly refers to the mean (statistical) difference between the height of cusps and valleys on a part and their deviation from that mean, at a macroscopic level. The most important consideration is that when 3D printing, most surface finishes are quite rough (deviate significantly from the mean), and thus are sanded down considerably to knock out the cusps left by the printer. This post processing can negatively affect the form of the final part.

Note that ''a proper mechanical fit between components demands a good tolerance on form, feature position, and surface finish'', such that it is typically impossible to obtain a proper fit when 3D printing, and that if you are considering the 3D printing of critically interfacing components, 3D printing should not be used unless post processing ''is built into the design''. For mechanical designs, you will notice that a main application is brackets. This is because brackets only need good positional tolerance on holes and mating faces, which 3D printing can almost always provide (the tolerance on form for holes is not that important since they are typically clearance holes). However, since some brackets are easily laser cut, 3D printing brackets is only done under certain specific conditions. It certainly has shown its commercial use in cost cutting by replacing intricate multi-part assemblies by ''generatively designed'' (we'll say computer generated for now) parts, as shown in the picture below.
[[File:Design for 3D Printing Generatively Designed Bracket.jpg|center|thumb|600x600px|A metal 3D printed generatively designed bracket (computer generated from load data, using Finite Element Analysis), likely replacing a multitude of other parts that would have been manufactured using traditional manufacturing methods which would lead to a heavier and more expensive bracket.<ref>CarrusHome (2021). GM Explores 3D printing, generative design for next gen parts. Consulted on 05-05-2022 at <nowiki>https://www.carrushome.com/en/gm-explores-3d-printing-generative-design-for-next-gen-parts/</nowiki></ref>]]

==[[Digital technologies/3D printing/3D modeling- Intermediate/CAD Extensions|CAD File Formats]] ==
In the beginner section of 3D modeling, you were introduced to TinkerCAD. In the instructions, you were instructed to export your 3D designs as a STL or OBJ file. In this section, the differences between different CAD file formats will be discussed.

=== [https://en.wikipedia.org/wiki/STL_(file_format) Standard Triangle Language (*.STL)] ===
[[File:STL format.png|thumb|Facets used to represent a cube and a sphere.]]
[[File:Vector coordinates of STL format.png|thumb|305x305px|Visual representation of the vertices and the normal vector.]]
STL files are the most used file format in 3D printing and 3D modeling. Most 3D printers support the file format. Many of the 3D printable models online are also found in STL file format. STL stands for stereolithography, a 3D printing process created at 3D Systems in <ins>the </ins>1980s. STL file format encodes the surface geometry of a 3D object. This is done through tessellation, a process of tiling a surface with one or more geometric shapes so there are no overlaps or gaps. The basic method of tessellating the outer surface of 3D models is through the use of tiny triangles (called “facets”) and store information about the facets in a file. For example, in the figure below, it shows how a cube can be represented by 12 triangles while 17000+ triangles are needed to represent a sphere. Since triangles consist of three straight edges, it can be difficult to approximate curved geometries. To do so, mesh density is increased, and individual triangle’s size is decreased.

STL file format stores the information as the coordinates of the vertices and the components of the unit normal vector to the triangle. The normal vector point outwards of the 3D model.
[[File:STL tessellation .png|left|thumb|Invalid tessellation on the left, acceptable tessellation on the right]]
There are a couple of rules for tessellation and storing information. The vertex rule states that each triangle must share two vertices with its neighbouring triangles.

The orientation rule states that the orientation of the facet must be specified in two ways. The direction of the normal should point outwards, and the vertices are listed in counter-clockwise when looking at the object from the outside.

The all-positive octant rule states that the coordinates of the triangle vertices must all be positive. This ensures that all coordinates stored would be in the positive which would save space in the file. Finally, the triangle sorting rule recommends that the triangles appear in ascending z-value order. This is a recommendation rather than a rule as it helps the software slice the models faster.
[[File:STL orientation rule.png|center|thumb|525x525px|Visual representation of the orientation rule.]]

=== [https://en.wikipedia.org/wiki/Wavefront_.obj_file Wavefront OBJ (*.OBJ)] ===
OBJ is a crucial file format in 3D printing. It is generally preferred for multi-colour 3D printing. Often, it is used a s an interchange format for non-animated 3D models. OBJ file format stores information about 3D models by encoding the surface geometry of the model. It also stores information about its colour and texture. It does not store any data about animations or scene. It is open source and neutral. Therefore, it is often used to share 3D models since many CAD software supports the format.
[[File:OBJ file .png|thumb|Freeform curves on 3D model surface]]
It differs from STL since it stores colour and texture information. STL is an older file format that is missing modern features. It does not support multi colour printing or high resolution prints. OBJ can approximate surface geometry well without drastically increasing the file size. It also supports multiple colours and textures in the same model.

OBJ encodes surface geometry of a 3D object in many different methods: Tessellation with polygonal faces, freeform curves and freeform surfaces. Similar to STL, OBJ allows tessellation of the surfaces with simple geometric shapes like triangles or more complex polygon. This is the simplest way to describe surface geometry. However, approximating curved surfaces with polygons will introduce coarseness and geometric deviation from the model. The size of the polygons can be decreased to increase the quality of the prints. However, this can lead to giant file sizes which can be difficult for 3D printers to handle. It is important to find the right balance between print quality and file sizes.

The surface geometry can also be defined using freeform curves. The user defines a collection of free form curves that runs along the surface of the model. The surface is then approximated using the collection of curves. It is more complicated than polygonal faces, but it allows for fewer data to describe the same surface. The curved lines can be described using freeform curves with a few mathematical parameters. It allows for higher quality encoding without drastically increasing the file size.

=== DS Solidworks Parts (*.SLDPRT) and DS Solidworks Assemblies (*.SLDASM) ===
Sldprt file formats are native SolidWorks file extensions. It provides details on specific parts within a system. This is a software specific file format. Opening SolidWorks files in slicers and other software may cause some corruption of your designs. However, because it is software specific, it contains the most information about your models. As such, you should do all your modeling while the files are in native format

=== [https://en.wikipedia.org/wiki/ISO_10303 ISO10303 - Standard for the Exchange of Product model data (*.STP, *.STEP)] ===
STEP file format is a neutral file format. It is the most common file format used to share 3D designs. This allows users to open others’ designs using the software of their choice. It stores 3D images in an ASCII format. While STEP files can be opened with most CAD software. It is not easily edited. The model will display as a finalized object. Users cannot edit specific dimensions or features of the model.

===Polygonal Formats===

*[https://en.wikipedia.org/wiki/STL_(file_format) Standard Triangle Language (*.STL)]
*[https://en.wikipedia.org/wiki/Wavefront_.obj_file Wavefront OBJ (*.OBJ)]
*[https://en.wikipedia.org/wiki/3D_Manufacturing_Format 3D Manufacturing Format (*.3MF)]

===NURBS Formats===

====Standard====

*[https://en.wikipedia.org/wiki/ISO_10303 ISO10303 - Standard for the Exchange of Product model data (*.STP, *.STEP)]
*[https://en.wikipedia.org/wiki/AutoCAD_DXF AutoCAD Drawing Exchange Format (*.DXF/*.DWG)]
*[https://en.wikipedia.org/wiki/IGES Initial Graphics Exchange Specification (*.IGES)] (standard last updated 1996)

====Software-Specific====

*DS Solidworks Parts (*.SLDPRT)
*DS Solidworks Assemblies (*.SLDASM)
*DS CATIA V5 Parts (*.CGR/*.CATPart)
*DS CATIA V5 Assemblies (*.CGR/*.CATProduct)
*PTC Creo Parts (*.PRT)
*PTC Creo Assemblies (*.ASM)

*Fusion 360 (*.F3D)

It should be noted that Fusion360 stores files on the cloud, such that locally saved .f3d files are not commonly encountered. It should also be noted that OnShape does not have a file format given it is hosted entirely on the cloud.

==[[Digital technologies/3D printing/3D modeling- Intermediate/Using Parametric NURBS Software|Introduction to Fusion360]]==
TinkerCAD is known for its simplicity, meaning it is easy to learn and use. However, its capabilities are limited. It uses a drag and drop method to create basic geometries. Theses shapes can be grouped to create more complex geometries but it takes more time to design something complex and has less flexibility. Fusion<ins> </ins>360 is a sketch-based CAD modeling software that allows for users to completely customize their design. It allows users to design 3D objects using 2D sketches.

Fusion 360 offers 3D CAD modeling, PCB design, and 3D simulation capabilities. It is a fee-based subscription software, however, a free version is offered for personal use. The free version has some limited capabilities but most of the 3D CAD features are offered. Even with the limited features it offers more design options than TinkerCAD. To download the software, you can use your AutoCAD account and follow the link below: <nowiki>https://www.autodesk.ca/en/products/fusion-360/personal</nowiki>

Just like TinkerCAD, and with any CAD modeling software you choose to use<ins>,</ins><s>. Y</s><ins> y</ins>ou can export your part designs as an STL file. Using this file format, you can use any slicer of your choice to slice the design into a gcode file to print.

=== Fusion 360 User Interface ===
[[File:User Interface of Fusion 360.png|center|959x959px]]
There are 5 main areas of the user interface. When the software is first launched, you should be seeing the screen above.

# Data Panel: On the left is the data panel. It displays pinned and recent projects, providing easy access to these projects for the users. It will also display sample projects that corresponds to the tutorials offered by AutoCAD. Users can also upload their projects to be shared with others for collaboration.
# Tool Bar: On the top of the screen sits the tool bar. Through this, you can use any of the features displayed to manipulate the 3D model you create. The shortcuts can be customized to display the ones you favour.
# Browser: Located at the top left of the main screen. It displays the model design with a file tree structure listing all the components, bodies and constructing plane. The files can be navigated through by clicking on their names. They can also be renamed by double clicking. The files can be collapsed using the triangles. The visibility of the bodies and planes can be toggled by clicking on the lightbulb.
# Timeline: The timeline of the design history is displayed at the bottom of the screen. This is a special feature of Fusion<ins> </ins>360 that is different from other CAD software. It keeps a record of the construction of the 3D model allowing the users to playback the building of the model. This feature also allow<ins>s</ins> users to add to the model from a previous state of the model.
# Navigation bar: The navigation bard allows users to change the view of the model. These features exist<s>s</s> as shortcuts when used with a mouse. For this reason, it is recommended to create CAD models using a physical mouse instead of a track pad. Some features include:
#* Zoom In/Out by scrolling up/down with the mouse.
#* Pan the model by holding down the wheel of the mouse.
#* Orbit the model by holding down control + wheel.

=== Sketching ===
The sketch function is the most important feature of a CAD program. It allows users to sketch 2D drawings as the base to create 3D objects.
[[File:Sketch Interface.png|center|650x650px]]
To create a rectangle, first click on “Create Sketch” from the tool bar above. Select the desired sketch plane. In the example above, YZ plane was selected. This is the plane which the 2D sketch will be created. You’ll notice the tool bar above has transformed to display sketch functions. Select “2-Point Rectangle” from the tool bar. Click on the origin of the sketch plane and drag to create a desired rectangle. The sketch features are defined with reference to the origin to position it in space. It is why it is recommended to have one vertex of the sketch to be defined as the origin. After the rectangle is drawn, you can define the dimensions of the 2 sides of the rectangle. You can toggle between the dimensions by using the “Tab” key on your keyboard. Press enter to confirm the sketch.
[[File:Fusion 360 Rectangle Sketch.png|center|600x600px]]
Next, the line tool will be introduced. Drawing a line is the most simple and versatile function of sketch. It will allow you to create any shapes you will need. Select the “Line” option from the tool bar. Hover your mouse over the rectangle, the mouse will be drawn to the line and an ‘X’ will appear. This means that one end of the line will intersect with the rectangle. Move the mouse towards the middle of the line on the rectangle until a triangle icon shows up. This signifies the midpoint of the line. Click to create the start of the line segment. Drag the mouse to create the line and click again to create the end of the line. You can also manipulate the dimension of the line manually by entering the value.
[[File:Fusion 360 Line Sketch.png|center|649x649px]]
To draw the line at an angle, drag the line out at an angle. At this point, there should be an angle dimension displayed. This value can be altered manually.

To create an arc, select “Create” -> “Arc” -> “Tangent Arc” from the tool bar. This will create an arc tangent to two other entities. Left click on the vertex of where you would like the arc to connect. Then click on the other vertex to connect. Alternative to create arcs include 3-point arcs where you select the two vertex and the middle point of the arc or center point arc when the arc is create<ins>d</ins> by finding the center of the arc.
[[File:Arc Sketch.png|center|648x648px]]

In order for a 2D sketch to be converted to 3D model, the 2D profile has to be a closed shape. This means all the lines and entities have to form a closed loop. This will be indicated with a light-blue shading inside the sketch.

=== Extrusion ===
The simplest way to create a 3D model is by extruding a 2D sketch, which adds a third dimension to the 2D sketch. Select “Extrude” from the toolbar. Hover the mouse over the sketch, closed shapes that can be extruded will be highlighted when hovered on. To select multiple shapes, left click on both shapes. In the extrusion settings that pops up on the right, enter the value for the third dimension of the sketch, the width. Click “OK” to confirm the extrusion.
[[File:Extrusion example.png|center|650x650px]]
You can select a new surface from the extruded object to sketch on. To do so, select “Create Sketch” and select the surface you would like to sketch on as the plane. Afterwards continue to sketch like normal.

Extrusion can also be used to cut. Sketch on the surface of the shape the geometry you would like to cut. Select “Extrude” tool and select the shapes you would like to cut. To remove material, enter a negative value in the dimension window. This indicates the direction you would like the extrusion to occur. On the screen, it will display a red region to indicate material removal. Press enter to confirm the operation.
[[File:Extrusion cut example.png|center|650x650px]]

=== Mirror ===
The mirror tool is an extremely powerful tool that can save the user a lot of time in creating the 3D models. This is especially useful when creating symmetrical objects. It allows users to mirror solid or small features. It does require the user to define the plane to mirror the features. There are many ways to create the plane. One of which is to “Offset Plane”
[[File:Mirror Example.png|center|650x650px]]

Under the “Construct” drop-down menu from the toolbar, select “Offset Plane”. Select a surface to offset from. This surface should be parallel from the plane you would like to create. Now enter the dimension you would like to offset the plane from the surface. Press enter when completed.

After the plane has been created, you can now mirror the features. Select “Mirror” under the drop<ins>-</ins> down menu from “Create” from the toolbar. Under “Type” parameter, you can select bodies, faces, features, or components. After the type has been selected, click on “Select” by Object and then the features you would like to mirror, you can also click on the features from the design history timeline. Then click on “Select” by Mirror Plane and the plane you would to mirror from. Now a preview will be displayed<ins>,</ins> to confirm press enter.

=== Fillet ===
Filleting the edges is a feature that is offered in Fusion 360 and not TinkerCAD. It can easily elevate your models. It creates rounded surfaces by adding or removing from a solid model.
[[File:Fillet Example.png|center|650x650px]]

# Select “Fillet” under the modify menu from the tool bar.
# Click on the edges you would like to round out.
# Enter a radius value to round the edges out to.
# Click “OK” to finalize.

== References ==
<references />

File:Fillet Example.png

2023-08-25T19:24:21Z

Cecilial:

Fusion360 Fillet example

File:Mirror Example.png

2023-08-25T19:21:29Z

Cecilial:

Fusion360 Mirror Example

File:Extrusion cut example.png

2023-08-25T19:20:21Z

Cecilial:

Fusion360 Extrusion Cut Example

File:Extrusion example.png

2023-08-25T19:18:55Z

Cecilial:

Fusion360 extrusion example

File:Arc Sketch.png

2023-08-25T19:15:32Z

Cecilial:

Fusion360 Arc Sketch with fully defined sketch example

Digital technologies/3D printing/3D modeling- Intermediate

2023-08-25T19:14:35Z

Cecilial: /* Introduction to Fusion360 */

TinkerCAD is nice for smaller parts with very little complexity. However, since it is not [https://en.wikipedia.org/wiki/Non-uniform_rational_B-spline NURBS] based nor parametric, it lacks major functionality. It is strongly suggested at this stage that TinkerCAD, Blender, Cinema 4D or other [https://en.wikipedia.org/wiki/Polygonal_modeling polygonal modelling] (non-NURBS) applications be set aside for parametric CAD software, such as [https://www.autodesk.ca/en/products/fusion-360 Autodesk Fusion 360] ([https://www.autodesk.ca/en/products/fusion-360/students-teachers-educators free for students. teachers, and educators]), [https://www.solidworks.com/ Dassault Systèmes Solidworks] (available through Remote Apps) or [https://www.onshape.com/en/ PTC OnShape] (completely online, free for students and educators) be used for mechanical design, as models made with such software contain much richer data that allows going from CAD models to manufacturing data. Polygonal modelling remains, however, an important tool for Scan to CAD, and such the intermediate CAD user should have a complete understanding of polygonal modelling software such as TinkerCAD.

==[[Digital technologies/3D printing/3D modeling- Intermediate/TinkerCAD (contd.)|Complex Shapes in TinkerCAD]]==
[[File:Heart Button TinkerCAD.png|left|thumb|Heart button CAD model|200x200px]]
In the beginner section of 3D modeling, you learned how to group shapes together. In advanced TinkerCAD, you will use the skills you have gained to create more complex shapes. TinkerCAD provides you with basic geometries such as cubes and cylinders. You can combine these shapes to create more complex geometries such as a house using the group function. To create even more complicated designs, you can combine shapes to be used to create complex holes

The example below will walk you through the making of a heart button. It will involve grouping shapes together in order to create a more complex shape and feature
[[File:Heart_Button_Construction.png|alt=|thumb|351x351px|Combining simple shapes like cylinders and cubes to create heart shape. ]]
# Add a box shape to the workspace. Make sure the dimension of the box has the thickness of the desired button. This will serve as the point of the heart.
# Add two cylinders with the same thickness as the box to two edges of the box. Set the diameter of the cylinder as the width of the box. This will create the humps of the heart.
# Using the round roof object, size it to the appropriate dimension for the button hoop.
# Copy and paste<s>r</s> a second round roof object and make it slightly smaller to be used to create the hole for the button hoop.
# Turn the object into a hole and position it accordingly.
# Finally, group the shapes together and the button is completed.

== [[Digital technologies/3D printing/3D modeling- Intermediate/Design for 3D Printing|Design for 3D Printing]] ==
There are some important things to note when modeling for 3D printing. It is important to optimize the print by decreasing print time and material while ensuring accuracy and strength of the part.

# Divide your model into smaller more manageable parts. There are many designs with complex details or large dimensions that would be more manageable prints if split into multiple parts. [[File:Multiple parts 3D print.png|center|thumb|599x599px|3D printed hand built with multiple parts. Finger is attached afterwards. ]]
# Try to ensure that there is one flat surface on the print. This will allow easier print set-up. The flat side can adhere to the build plate, minimizing the need for additional build plate adhesion.[[File:Prints in different orientation.png|center|thumb|300x300px|Traffic cone printed in two different orientations. It demonstrates the optimal orientation with the least amount of supports. ]]
# Avoid floating parts. All aspect of the model should be connected to the main model. Minimize overhangs in the model as well. This will prevent wasted time and material to print supports.[[File:Supports under floating parts.png|center|thumb|480x480px|Printed gearbox with floating parts with supports under them. ]]
# FDM printing has limited capabilities with dimensional accuracy. It is recommended to prevent printing horizontally oriented holes of the smaller size. These holes are often deformed and printed with difficult to remove supports.[[File:Holes printed vertically and horizontally..png|center|thumb|500x500px|Holes printed vertically on the left and horizontally with the layers on the right. ]]
# Printed parts are stronger in one direction than another. It is important to keep this in mind when designing. Prints will be weaker in the areas where the layers meet. This means that printed parts have low tensile strength along the Z-axis. The prints will be the strongest in planes parallel to the build surface.[[File:Layers printed in different axis.png|center|thumb|500x500px]]
# Exaggerate the details of your designs. This is an important thing to keep in mind. In order for details to show up on small designs, you should make your cuts deeper and bigger. It can also be helpful to make slender designs thicker.[[File:Details on 3D prints.png|center|thumb|450x450px|Details on CAD on the left with the same details printed on the right. ]]
# Round surfaces will not show up smoothly. Since FDM prints in layers, it will cause the rounded surfaces to look jagged. To achieve a smooth surface, additional processing will be required. [[File:3D printed surface .png|center|thumb|449x449px|3D printed surface with all the layers before and after additional processing. ]]

If your design is to be used in (electro-)mechanical assemblies in which there are interfacing components, it is important that you understand three basic tolerancing concepts and to keep them in the back of your mind when modeling or more generally designing these assemblies.

# Form: The form of a part refers to the overall dimensions and the shape of the exterior surfaces of a component. Think of a flaw referring to form as a print that ended up not matching the base geometry that was used to create it in CAD due to adverse physical variables during the printing process. Examples follow:
## A ''sphere'' may end up slightly ''oval'' once printed due to improper cooling, etc.;
## A pillar might end up tilted to one side due to improper belt tension between the belt axes, etc.;
## A pin feature might end up too large to fit its mating hole due to the printer outputting too much material when producing the outer walls of the feature (the inverse can also be true).
# Position: Position refers to the distance separating a feature and an (ideally) meaningful reference (i.e.: the distance between a hole and the side of a part, or between two holes). Thankfully, flaws pertaining to position are rare on a properly tuned printer, as the printer does not have any information about existing references other than the build plate. If tuned properly, the printer will always print a feature at a position (X,Y,Z) distance relative to another feature, because that is what the gCode will tell it to do. You can imagine, however, that if the part is warped, the 'build plate reference' is no longer valid, and such, warped parts almost always have features out of position ''unless the meaningful reference (interfacing feature) used in the design is not the build plate''. However, since the build plate reference is such an important one to define the Z position of features (for the printer, that is), making your meaningful reference something other than the build plate does not always guarantee you good positional tolerance independent of warping.
# Surface: The surface finish of a part is a rather complex subject. In 3D printing, and for typical applications of 3D printed parts, it mostly refers to the mean (statistical) difference between the height of cusps and valleys on a part and their deviation from that mean, at a macroscopic level. The most important consideration is that when 3D printing, most surface finishes are quite rough (deviate significantly from the mean), and thus are sanded down considerably to knock out the cusps left by the printer. This post processing can negatively affect the form of the final part.

Note that ''a proper mechanical fit between components demands a good tolerance on form, feature position, and surface finish'', such that it is typically impossible to obtain a proper fit when 3D printing, and that if you are considering the 3D printing of critically interfacing components, 3D printing should not be used unless post processing ''is built into the design''. For mechanical designs, you will notice that a main application is brackets. This is because brackets only need good positional tolerance on holes and mating faces, which 3D printing can almost always provide (the tolerance on form for holes is not that important since they are typically clearance holes). However, since some brackets are easily laser cut, 3D printing brackets is only done under certain specific conditions. It certainly has shown its commercial use in cost cutting by replacing intricate multi-part assemblies by ''generatively designed'' (we'll say computer generated for now) parts, as shown in the picture below.
[[File:Design for 3D Printing Generatively Designed Bracket.jpg|center|thumb|600x600px|A metal 3D printed generatively designed bracket (computer generated from load data, using Finite Element Analysis), likely replacing a multitude of other parts that would have been manufactured using traditional manufacturing methods which would lead to a heavier and more expensive bracket.<ref>CarrusHome (2021). GM Explores 3D printing, generative design for next gen parts. Consulted on 05-05-2022 at <nowiki>https://www.carrushome.com/en/gm-explores-3d-printing-generative-design-for-next-gen-parts/</nowiki></ref>]]

==[[Digital technologies/3D printing/3D modeling- Intermediate/CAD Extensions|CAD File Formats]] ==
In the beginner section of 3D modeling, you were introduced to TinkerCAD. In the instructions, you were instructed to export your 3D designs as a STL or OBJ file. In this section, the differences between different CAD file formats will be discussed.

=== [https://en.wikipedia.org/wiki/STL_(file_format) Standard Triangle Language (*.STL)] ===
[[File:STL format.png|thumb|Facets used to represent a cube and a sphere.]]
[[File:Vector coordinates of STL format.png|thumb|305x305px|Visual representation of the vertices and the normal vector.]]
STL files are the most used file format in 3D printing and 3D modeling. Most 3D printers support the file format. Many of the 3D printable models online are also found in STL file format. STL stands for stereolithography, a 3D printing process created at 3D Systems in <ins>the </ins>1980s. STL file format encodes the surface geometry of a 3D object. This is done through tessellation, a process of tiling a surface with one or more geometric shapes so there are no overlaps or gaps. The basic method of tessellating the outer surface of 3D models is through the use of tiny triangles (called “facets”) and store information about the facets in a file. For example, in the figure below, it shows how a cube can be represented by 12 triangles while 17000+ triangles are needed to represent a sphere. Since triangles consist of three straight edges, it can be difficult to approximate curved geometries. To do so, mesh density is increased, and individual triangle’s size is decreased.

STL file format stores the information as the coordinates of the vertices and the components of the unit normal vector to the triangle. The normal vector point outwards of the 3D model.
[[File:STL tessellation .png|left|thumb|Invalid tessellation on the left, acceptable tessellation on the right]]
There are a couple of rules for tessellation and storing information. The vertex rule states that each triangle must share two vertices with its neighbouring triangles.

The orientation rule states that the orientation of the facet must be specified in two ways. The direction of the normal should point outwards, and the vertices are listed in counter-clockwise when looking at the object from the outside.

The all-positive octant rule states that the coordinates of the triangle vertices must all be positive. This ensures that all coordinates stored would be in the positive which would save space in the file. Finally, the triangle sorting rule recommends that the triangles appear in ascending z-value order. This is a recommendation rather than a rule as it helps the software slice the models faster.
[[File:STL orientation rule.png|center|thumb|525x525px|Visual representation of the orientation rule.]]

=== [https://en.wikipedia.org/wiki/Wavefront_.obj_file Wavefront OBJ (*.OBJ)] ===
OBJ is a crucial file format in 3D printing. It is generally preferred for multi-colour 3D printing. Often, it is used a s an interchange format for non-animated 3D models. OBJ file format stores information about 3D models by encoding the surface geometry of the model. It also stores information about its colour and texture. It does not store any data about animations or scene. It is open source and neutral. Therefore, it is often used to share 3D models since many CAD software supports the format.
[[File:OBJ file .png|thumb|Freeform curves on 3D model surface]]
It differs from STL since it stores colour and texture information. STL is an older file format that is missing modern features. It does not support multi colour printing or high resolution prints. OBJ can approximate surface geometry well without drastically increasing the file size. It also supports multiple colours and textures in the same model.

OBJ encodes surface geometry of a 3D object in many different methods: Tessellation with polygonal faces, freeform curves and freeform surfaces. Similar to STL, OBJ allows tessellation of the surfaces with simple geometric shapes like triangles or more complex polygon. This is the simplest way to describe surface geometry. However, approximating curved surfaces with polygons will introduce coarseness and geometric deviation from the model. The size of the polygons can be decreased to increase the quality of the prints. However, this can lead to giant file sizes which can be difficult for 3D printers to handle. It is important to find the right balance between print quality and file sizes.

The surface geometry can also be defined using freeform curves. The user defines a collection of free form curves that runs along the surface of the model. The surface is then approximated using the collection of curves. It is more complicated than polygonal faces, but it allows for fewer data to describe the same surface. The curved lines can be described using freeform curves with a few mathematical parameters. It allows for higher quality encoding without drastically increasing the file size.

=== DS Solidworks Parts (*.SLDPRT) and DS Solidworks Assemblies (*.SLDASM) ===
Sldprt file formats are native SolidWorks file extensions. It provides details on specific parts within a system. This is a software specific file format. Opening SolidWorks files in slicers and other software may cause some corruption of your designs. However, because it is software specific, it contains the most information about your models. As such, you should do all your modeling while the files are in native format

=== [https://en.wikipedia.org/wiki/ISO_10303 ISO10303 - Standard for the Exchange of Product model data (*.STP, *.STEP)] ===
STEP file format is a neutral file format. It is the most common file format used to share 3D designs. This allows users to open others’ designs using the software of their choice. It stores 3D images in an ASCII format. While STEP files can be opened with most CAD software. It is not easily edited. The model will display as a finalized object. Users cannot edit specific dimensions or features of the model.

===Polygonal Formats===

*[https://en.wikipedia.org/wiki/STL_(file_format) Standard Triangle Language (*.STL)]
*[https://en.wikipedia.org/wiki/Wavefront_.obj_file Wavefront OBJ (*.OBJ)]
*[https://en.wikipedia.org/wiki/3D_Manufacturing_Format 3D Manufacturing Format (*.3MF)]

===NURBS Formats===

====Standard====

*[https://en.wikipedia.org/wiki/ISO_10303 ISO10303 - Standard for the Exchange of Product model data (*.STP, *.STEP)]
*[https://en.wikipedia.org/wiki/AutoCAD_DXF AutoCAD Drawing Exchange Format (*.DXF/*.DWG)]
*[https://en.wikipedia.org/wiki/IGES Initial Graphics Exchange Specification (*.IGES)] (standard last updated 1996)

====Software-Specific====

*DS Solidworks Parts (*.SLDPRT)
*DS Solidworks Assemblies (*.SLDASM)
*DS CATIA V5 Parts (*.CGR/*.CATPart)
*DS CATIA V5 Assemblies (*.CGR/*.CATProduct)
*PTC Creo Parts (*.PRT)
*PTC Creo Assemblies (*.ASM)

*Fusion 360 (*.F3D)

It should be noted that Fusion360 stores files on the cloud, such that locally saved .f3d files are not commonly encountered. It should also be noted that OnShape does not have a file format given it is hosted entirely on the cloud.

==[[Digital technologies/3D printing/3D modeling- Intermediate/Using Parametric NURBS Software|Introduction to Fusion360]]==
TinkerCAD is known for its simplicity, meaning it is easy to learn and use. However, its capabilities are limited. It uses a drag and drop method to create basic geometries. Theses shapes can be grouped to create more complex geometries but it takes more time to design something complex and has less flexibility. Fusion<ins> </ins>360 is a sketch-based CAD modeling software that allows for users to completely customize their design. It allows users to design 3D objects using 2D sketches.

Fusion 360 offers 3D CAD modeling, PCB design, and 3D simulation capabilities. It is a fee-based subscription software, however, a free version is offered for personal use. The free version has some limited capabilities but most of the 3D CAD features are offered. Even with the limited features it offers more design options than TinkerCAD. To download the software, you can use your AutoCAD account and follow the link below: <nowiki>https://www.autodesk.ca/en/products/fusion-360/personal</nowiki>

Just like TinkerCAD, and with any CAD modeling software you choose to use<ins>,</ins><s>. Y</s><ins> y</ins>ou can export your part designs as an STL file. Using this file format, you can use any slicer of your choice to slice the design into a gcode file to print.

=== Fusion 360 User Interface ===
[[File:User Interface of Fusion 360.png|center|959x959px]]
There are 5 main areas of the user interface. When the software is first launched, you should be seeing the screen above.

# Data Panel: On the left is the data panel. It displays pinned and recent projects, providing easy access to these projects for the users. It will also display sample projects that corresponds to the tutorials offered by AutoCAD. Users can also upload their projects to be shared with others for collaboration.
# Tool Bar: On the top of the screen sits the tool bar. Through this, you can use any of the features displayed to manipulate the 3D model you create. The shortcuts can be customized to display the ones you favour.
# Browser: Located at the top left of the main screen. It displays the model design with a file tree structure listing all the components, bodies and constructing plane. The files can be navigated through by clicking on their names. They can also be renamed by double clicking. The files can be collapsed using the triangles. The visibility of the bodies and planes can be toggled by clicking on the lightbulb.
# Timeline: The timeline of the design history is displayed at the bottom of the screen. This is a special feature of Fusion<ins> </ins>360 that is different from other CAD software. It keeps a record of the construction of the 3D model allowing the users to playback the building of the model. This feature also allow<ins>s</ins> users to add to the model from a previous state of the model.
# Navigation bar: The navigation bard allows users to change the view of the model. These features exist<s>s</s> as shortcuts when used with a mouse. For this reason, it is recommended to create CAD models using a physical mouse instead of a track pad. Some features include:
#* Zoom In/Out by scrolling up/down with the mouse.
#* Pan the model by holding down the wheel of the mouse.
#* Orbit the model by holding down control + wheel.

=== Sketching ===
The sketch function is the most important feature of a CAD program. It allows users to sketch 2D drawings as the base to create 3D objects.
[[File:Sketch Interface.png|center|650x650px]]
To create a rectangle, first click on “Create Sketch” from the tool bar above. Select the desired sketch plane. In the example above, YZ plane was selected. This is the plane which the 2D sketch will be created. You’ll notice the tool bar above has transformed to display sketch functions. Select “2-Point Rectangle” from the tool bar. Click on the origin of the sketch plane and drag to create a desired rectangle. The sketch features are defined with reference to the origin to position it in space. It is why it is recommended to have one vertex of the sketch to be defined as the origin. After the rectangle is drawn, you can define the dimensions of the 2 sides of the rectangle. You can toggle between the dimensions by using the “Tab” key on your keyboard. Press enter to confirm the sketch.
[[File:Fusion 360 Rectangle Sketch.png|center|600x600px]]
Next, the line tool will be introduced. Drawing a line is the most simple and versatile function of sketch. It will allow you to create any shapes you will need. Select the “Line” option from the tool bar. Hover your mouse over the rectangle, the mouse will be drawn to the line and an ‘X’ will appear. This means that one end of the line will intersect with the rectangle. Move the mouse towards the middle of the line on the rectangle until a triangle icon shows up. This signifies the midpoint of the line. Click to create the start of the line segment. Drag the mouse to create the line and click again to create the end of the line. You can also manipulate the dimension of the line manually by entering the value.
[[File:Fusion 360 Line Sketch.png|center|649x649px]]
To draw the line at an angle, drag the line out at an angle. At this point, there should be an angle dimension displayed. This value can be altered manually.

To create an arc, select “Create” -> “Arc” -> “Tangent Arc” from the tool bar. This will create an arc tangent to two other entities. Left click on the vertex of where you would like the arc to connect. Then click on the other vertex to connect. Alternative to create arcs include 3-point arcs where you select the two vertex and the middle point of the arc or center point arc when the arc is create<ins>d</ins> by finding the center of the arc.

In order for a 2D sketch to be converted to 3D model, the 2D profile has to be a closed shape. This means all the lines and entities have to form a closed loop. This will be indicated with a light-blue shading inside the sketch.

=== Extrusion ===
The simplest way to create a 3D model is by extruding a 2D sketch, which adds a third dimension to the 2D sketch. Select “Extrude” from the toolbar. Hover the mouse over the sketch, closed shapes that can be extruded will be highlighted when hovered on. To select multiple shapes, left click on both shapes. In the extrusion settings that pops up on the right, enter the value for the third dimension of the sketch, the width. Click “OK” to confirm the extrusion.

You can select a new surface from the extruded object to sketch on. To do so, select “Create Sketch” and select the surface you would like to sketch on as the plane. Afterwards continue to sketch like normal.

Extrusion can also be used to cut. Sketch on the surface of the shape the geometry you would like to cut. Select “Extrude” tool and select the shapes you would like to cut. To remove material, enter a negative value in the dimension window. This indicates the direction you would like the extrusion to occur. On the screen, it will display a red region to indicate material removal. Press enter to confirm the operation.

=== Mirror ===
The mirror tool is an extremely powerful tool that can save the user a lot of time in creating the 3D models. This is especially useful when creating symmetrical objects. It allows users to mirror solid or small features. It does require the user to define the plane to mirror the features. There are many ways to create the plane. One of which is to “Offset Plane”

Under the “Construct” drop-down menu from the toolbar, select “Offset Plane”. Select a surface to offset from. This surface should be parallel from the plane you would like to create. Now enter the dimension you would like to offset the plane from the surface. Press enter when completed.

After the plane has been created, you can now mirror the features. Select “Mirror” under the drop<ins>-</ins> down menu from “Create” from the toolbar. Under “Type” parameter, you can select bodies, faces, features, or components. After the type has been selected, click on “Select” by Object and then the features you would like to mirror, you can also click on the features from the design history timeline. Then click on “Select” by Mirror Plane and the plane you would to mirror from. Now a preview will be displayed<ins>,</ins> to confirm press enter.

=== Fillet ===
Filleting the edges is a feature that is offered in Fusion 360 and not TinkerCAD. It can easily elevate your models. It creates rounded surfaces by adding or removing from a solid model.

# Select “Fillet” under the modify menu from the tool bar.
# Click on the edges you would like to round out.
# Enter a radius value to round the edges out to.
# Click “OK” to finalize.

== References ==
<references />

File:Fusion 360 Line Sketch.png

2023-08-25T16:46:10Z

Cecilial:

Fusion 360 Line Sketched at an angle

File:Fusion 360 Rectangle Sketch.png

2023-08-25T16:39:41Z

Cecilial:

Fusion360 Rectangle Sketch

File:Sketch Interface.png

2023-08-25T16:37:06Z

Cecilial:

Sketching

File:User Interface of Fusion 360.png

2023-08-25T16:35:55Z

Cecilial:

Digital technologies/3D printing/3D modeling- Intermediate

2023-08-25T16:32:10Z

Cecilial: /* Design for 3D Printing */

TinkerCAD is nice for smaller parts with very little complexity. However, since it is not [https://en.wikipedia.org/wiki/Non-uniform_rational_B-spline NURBS] based nor parametric, it lacks major functionality. It is strongly suggested at this stage that TinkerCAD, Blender, Cinema 4D or other [https://en.wikipedia.org/wiki/Polygonal_modeling polygonal modelling] (non-NURBS) applications be set aside for parametric CAD software, such as [https://www.autodesk.ca/en/products/fusion-360 Autodesk Fusion 360] ([https://www.autodesk.ca/en/products/fusion-360/students-teachers-educators free for students. teachers, and educators]), [https://www.solidworks.com/ Dassault Systèmes Solidworks] (available through Remote Apps) or [https://www.onshape.com/en/ PTC OnShape] (completely online, free for students and educators) be used for mechanical design, as models made with such software contain much richer data that allows going from CAD models to manufacturing data. Polygonal modelling remains, however, an important tool for Scan to CAD, and such the intermediate CAD user should have a complete understanding of polygonal modelling software such as TinkerCAD.

==[[Digital technologies/3D printing/3D modeling- Intermediate/TinkerCAD (contd.)|Complex Shapes in TinkerCAD]]==
[[File:Heart Button TinkerCAD.png|left|thumb|Heart button CAD model|200x200px]]
In the beginner section of 3D modeling, you learned how to group shapes together. In advanced TinkerCAD, you will use the skills you have gained to create more complex shapes. TinkerCAD provides you with basic geometries such as cubes and cylinders. You can combine these shapes to create more complex geometries such as a house using the group function. To create even more complicated designs, you can combine shapes to be used to create complex holes

The example below will walk you through the making of a heart button. It will involve grouping shapes together in order to create a more complex shape and feature
[[File:Heart_Button_Construction.png|alt=|thumb|351x351px|Combining simple shapes like cylinders and cubes to create heart shape. ]]
# Add a box shape to the workspace. Make sure the dimension of the box has the thickness of the desired button. This will serve as the point of the heart.
# Add two cylinders with the same thickness as the box to two edges of the box. Set the diameter of the cylinder as the width of the box. This will create the humps of the heart.
# Using the round roof object, size it to the appropriate dimension for the button hoop.
# Copy and paste<s>r</s> a second round roof object and make it slightly smaller to be used to create the hole for the button hoop.
# Turn the object into a hole and position it accordingly.
# Finally, group the shapes together and the button is completed.

== [[Digital technologies/3D printing/3D modeling- Intermediate/Design for 3D Printing|Design for 3D Printing]] ==
There are some important things to note when modeling for 3D printing. It is important to optimize the print by decreasing print time and material while ensuring accuracy and strength of the part.

# Divide your model into smaller more manageable parts. There are many designs with complex details or large dimensions that would be more manageable prints if split into multiple parts. [[File:Multiple parts 3D print.png|center|thumb|599x599px|3D printed hand built with multiple parts. Finger is attached afterwards. ]]
# Try to ensure that there is one flat surface on the print. This will allow easier print set-up. The flat side can adhere to the build plate, minimizing the need for additional build plate adhesion.[[File:Prints in different orientation.png|center|thumb|300x300px|Traffic cone printed in two different orientations. It demonstrates the optimal orientation with the least amount of supports. ]]
# Avoid floating parts. All aspect of the model should be connected to the main model. Minimize overhangs in the model as well. This will prevent wasted time and material to print supports.[[File:Supports under floating parts.png|center|thumb|480x480px|Printed gearbox with floating parts with supports under them. ]]
# FDM printing has limited capabilities with dimensional accuracy. It is recommended to prevent printing horizontally oriented holes of the smaller size. These holes are often deformed and printed with difficult to remove supports.[[File:Holes printed vertically and horizontally..png|center|thumb|500x500px|Holes printed vertically on the left and horizontally with the layers on the right. ]]
# Printed parts are stronger in one direction than another. It is important to keep this in mind when designing. Prints will be weaker in the areas where the layers meet. This means that printed parts have low tensile strength along the Z-axis. The prints will be the strongest in planes parallel to the build surface.[[File:Layers printed in different axis.png|center|thumb|500x500px]]
# Exaggerate the details of your designs. This is an important thing to keep in mind. In order for details to show up on small designs, you should make your cuts deeper and bigger. It can also be helpful to make slender designs thicker.[[File:Details on 3D prints.png|center|thumb|450x450px|Details on CAD on the left with the same details printed on the right. ]]
# Round surfaces will not show up smoothly. Since FDM prints in layers, it will cause the rounded surfaces to look jagged. To achieve a smooth surface, additional processing will be required. [[File:3D printed surface .png|center|thumb|449x449px|3D printed surface with all the layers before and after additional processing. ]]

If your design is to be used in (electro-)mechanical assemblies in which there are interfacing components, it is important that you understand three basic tolerancing concepts and to keep them in the back of your mind when modeling or more generally designing these assemblies.

# Form: The form of a part refers to the overall dimensions and the shape of the exterior surfaces of a component. Think of a flaw referring to form as a print that ended up not matching the base geometry that was used to create it in CAD due to adverse physical variables during the printing process. Examples follow:
## A ''sphere'' may end up slightly ''oval'' once printed due to improper cooling, etc.;
## A pillar might end up tilted to one side due to improper belt tension between the belt axes, etc.;
## A pin feature might end up too large to fit its mating hole due to the printer outputting too much material when producing the outer walls of the feature (the inverse can also be true).
# Position: Position refers to the distance separating a feature and an (ideally) meaningful reference (i.e.: the distance between a hole and the side of a part, or between two holes). Thankfully, flaws pertaining to position are rare on a properly tuned printer, as the printer does not have any information about existing references other than the build plate. If tuned properly, the printer will always print a feature at a position (X,Y,Z) distance relative to another feature, because that is what the gCode will tell it to do. You can imagine, however, that if the part is warped, the 'build plate reference' is no longer valid, and such, warped parts almost always have features out of position ''unless the meaningful reference (interfacing feature) used in the design is not the build plate''. However, since the build plate reference is such an important one to define the Z position of features (for the printer, that is), making your meaningful reference something other than the build plate does not always guarantee you good positional tolerance independent of warping.
# Surface: The surface finish of a part is a rather complex subject. In 3D printing, and for typical applications of 3D printed parts, it mostly refers to the mean (statistical) difference between the height of cusps and valleys on a part and their deviation from that mean, at a macroscopic level. The most important consideration is that when 3D printing, most surface finishes are quite rough (deviate significantly from the mean), and thus are sanded down considerably to knock out the cusps left by the printer. This post processing can negatively affect the form of the final part.

Note that ''a proper mechanical fit between components demands a good tolerance on form, feature position, and surface finish'', such that it is typically impossible to obtain a proper fit when 3D printing, and that if you are considering the 3D printing of critically interfacing components, 3D printing should not be used unless post processing ''is built into the design''. For mechanical designs, you will notice that a main application is brackets. This is because brackets only need good positional tolerance on holes and mating faces, which 3D printing can almost always provide (the tolerance on form for holes is not that important since they are typically clearance holes). However, since some brackets are easily laser cut, 3D printing brackets is only done under certain specific conditions. It certainly has shown its commercial use in cost cutting by replacing intricate multi-part assemblies by ''generatively designed'' (we'll say computer generated for now) parts, as shown in the picture below.
[[File:Design for 3D Printing Generatively Designed Bracket.jpg|center|thumb|600x600px|A metal 3D printed generatively designed bracket (computer generated from load data, using Finite Element Analysis), likely replacing a multitude of other parts that would have been manufactured using traditional manufacturing methods which would lead to a heavier and more expensive bracket.<ref>CarrusHome (2021). GM Explores 3D printing, generative design for next gen parts. Consulted on 05-05-2022 at <nowiki>https://www.carrushome.com/en/gm-explores-3d-printing-generative-design-for-next-gen-parts/</nowiki></ref>]]

==[[Digital technologies/3D printing/3D modeling- Intermediate/CAD Extensions|CAD File Formats]] ==
In the beginner section of 3D modeling, you were introduced to TinkerCAD. In the instructions, you were instructed to export your 3D designs as a STL or OBJ file. In this section, the differences between different CAD file formats will be discussed.

=== [https://en.wikipedia.org/wiki/STL_(file_format) Standard Triangle Language (*.STL)] ===
[[File:STL format.png|thumb|Facets used to represent a cube and a sphere.]]
[[File:Vector coordinates of STL format.png|thumb|305x305px|Visual representation of the vertices and the normal vector.]]
STL files are the most used file format in 3D printing and 3D modeling. Most 3D printers support the file format. Many of the 3D printable models online are also found in STL file format. STL stands for stereolithography, a 3D printing process created at 3D Systems in <ins>the </ins>1980s. STL file format encodes the surface geometry of a 3D object. This is done through tessellation, a process of tiling a surface with one or more geometric shapes so there are no overlaps or gaps. The basic method of tessellating the outer surface of 3D models is through the use of tiny triangles (called “facets”) and store information about the facets in a file. For example, in the figure below, it shows how a cube can be represented by 12 triangles while 17000+ triangles are needed to represent a sphere. Since triangles consist of three straight edges, it can be difficult to approximate curved geometries. To do so, mesh density is increased, and individual triangle’s size is decreased.

STL file format stores the information as the coordinates of the vertices and the components of the unit normal vector to the triangle. The normal vector point outwards of the 3D model.
[[File:STL tessellation .png|left|thumb|Invalid tessellation on the left, acceptable tessellation on the right]]
There are a couple of rules for tessellation and storing information. The vertex rule states that each triangle must share two vertices with its neighbouring triangles.

The orientation rule states that the orientation of the facet must be specified in two ways. The direction of the normal should point outwards, and the vertices are listed in counter-clockwise when looking at the object from the outside.

The all-positive octant rule states that the coordinates of the triangle vertices must all be positive. This ensures that all coordinates stored would be in the positive which would save space in the file. Finally, the triangle sorting rule recommends that the triangles appear in ascending z-value order. This is a recommendation rather than a rule as it helps the software slice the models faster.
[[File:STL orientation rule.png|center|thumb|525x525px|Visual representation of the orientation rule.]]

=== [https://en.wikipedia.org/wiki/Wavefront_.obj_file Wavefront OBJ (*.OBJ)] ===
OBJ is a crucial file format in 3D printing. It is generally preferred for multi-colour 3D printing. Often, it is used a s an interchange format for non-animated 3D models. OBJ file format stores information about 3D models by encoding the surface geometry of the model. It also stores information about its colour and texture. It does not store any data about animations or scene. It is open source and neutral. Therefore, it is often used to share 3D models since many CAD software supports the format.
[[File:OBJ file .png|thumb|Freeform curves on 3D model surface]]
It differs from STL since it stores colour and texture information. STL is an older file format that is missing modern features. It does not support multi colour printing or high resolution prints. OBJ can approximate surface geometry well without drastically increasing the file size. It also supports multiple colours and textures in the same model.

OBJ encodes surface geometry of a 3D object in many different methods: Tessellation with polygonal faces, freeform curves and freeform surfaces. Similar to STL, OBJ allows tessellation of the surfaces with simple geometric shapes like triangles or more complex polygon. This is the simplest way to describe surface geometry. However, approximating curved surfaces with polygons will introduce coarseness and geometric deviation from the model. The size of the polygons can be decreased to increase the quality of the prints. However, this can lead to giant file sizes which can be difficult for 3D printers to handle. It is important to find the right balance between print quality and file sizes.

The surface geometry can also be defined using freeform curves. The user defines a collection of free form curves that runs along the surface of the model. The surface is then approximated using the collection of curves. It is more complicated than polygonal faces, but it allows for fewer data to describe the same surface. The curved lines can be described using freeform curves with a few mathematical parameters. It allows for higher quality encoding without drastically increasing the file size.

=== DS Solidworks Parts (*.SLDPRT) and DS Solidworks Assemblies (*.SLDASM) ===
Sldprt file formats are native SolidWorks file extensions. It provides details on specific parts within a system. This is a software specific file format. Opening SolidWorks files in slicers and other software may cause some corruption of your designs. However, because it is software specific, it contains the most information about your models. As such, you should do all your modeling while the files are in native format

=== [https://en.wikipedia.org/wiki/ISO_10303 ISO10303 - Standard for the Exchange of Product model data (*.STP, *.STEP)] ===
STEP file format is a neutral file format. It is the most common file format used to share 3D designs. This allows users to open others’ designs using the software of their choice. It stores 3D images in an ASCII format. While STEP files can be opened with most CAD software. It is not easily edited. The model will display as a finalized object. Users cannot edit specific dimensions or features of the model.

===Polygonal Formats===

*[https://en.wikipedia.org/wiki/STL_(file_format) Standard Triangle Language (*.STL)]
*[https://en.wikipedia.org/wiki/Wavefront_.obj_file Wavefront OBJ (*.OBJ)]
*[https://en.wikipedia.org/wiki/3D_Manufacturing_Format 3D Manufacturing Format (*.3MF)]

===NURBS Formats===

====Standard====

*[https://en.wikipedia.org/wiki/ISO_10303 ISO10303 - Standard for the Exchange of Product model data (*.STP, *.STEP)]
*[https://en.wikipedia.org/wiki/AutoCAD_DXF AutoCAD Drawing Exchange Format (*.DXF/*.DWG)]
*[https://en.wikipedia.org/wiki/IGES Initial Graphics Exchange Specification (*.IGES)] (standard last updated 1996)

====Software-Specific====

*DS Solidworks Parts (*.SLDPRT)
*DS Solidworks Assemblies (*.SLDASM)
*DS CATIA V5 Parts (*.CGR/*.CATPart)
*DS CATIA V5 Assemblies (*.CGR/*.CATProduct)
*PTC Creo Parts (*.PRT)
*PTC Creo Assemblies (*.ASM)

*Fusion 360 (*.F3D)

It should be noted that Fusion360 stores files on the cloud, such that locally saved .f3d files are not commonly encountered. It should also be noted that OnShape does not have a file format given it is hosted entirely on the cloud.

==[[Digital technologies/3D printing/3D modeling- Intermediate/Using Parametric NURBS Software|Introduction to Fusion360]]==
TinkerCAD is known for its simplicity, meaning it is easy to learn and use. However, its capabilities are limited. It uses a drag and drop method to create basic geometries. Theses shapes can be grouped to create more complex geometries but it takes more time to design something complex and has less flexibility. Fusion<ins> </ins>360 is a sketch-based CAD modeling software that allows for users to completely customize their design. It allows users to design 3D objects using 2D sketches.

Fusion 360 offers 3D CAD modeling, PCB design, and 3D simulation capabilities. It is a fee-based subscription software, however, a free version is offered for personal use. The free version has some limited capabilities but most of the 3D CAD features are offered. Even with the limited features it offers more design options than TinkerCAD. To download the software, you can use your AutoCAD account and follow the link below: <nowiki>https://www.autodesk.ca/en/products/fusion-360/personal</nowiki>

Just like TinkerCAD, and with any CAD modeling software you choose to use<ins>,</ins><s>. Y</s><ins> y</ins>ou can export your part designs as an STL file. Using this file format, you can use any slicer of your choice to slice the design into a gcode file to print.

=== Fusion 360 User Interface ===
There are 5 main areas of the user interface. When the software is first launched, you should be seeing the screen above.

# Data Panel: On the left is the data panel. It displays pinned and recent projects, providing easy access to these projects for the users. It will also display sample projects that corresponds to the tutorials offered by AutoCAD. Users can also upload their projects to be shared with others for collaboration.
# Tool Bar: On the top of the screen sits the tool bar. Through this, you can use any of the features displayed to manipulate the 3D model you create. The shortcuts can be customized to display the ones you favour.
# Browser: Located at the top left of the main screen. It displays the model design with a file tree structure listing all the components, bodies and constructing plane. The files can be navigated through by clicking on their names. They can also be renamed by double clicking. The files can be collapsed using the triangles. The visibility of the bodies and planes can be toggled by clicking on the lightbulb.
# Timeline: The timeline of the design history is displayed at the bottom of the screen. This is a special feature of Fusion<ins> </ins>360 that is different from other CAD software. It keeps a record of the construction of the 3D model allowing the users to playback the building of the model. This feature also allow<ins>s</ins> users to add to the model from a previous state of the model.
# Navigation bar: The navigation bard allows users to change the view of the model. These features exist<s>s</s> as shortcuts when used with a mouse. For this reason, it is recommended to create CAD models using a physical mouse instead of a track pad. Some features include:
#* Zoom In/Out by scrolling up/down with the mouse.
#* Pan the model by holding down the wheel of the mouse.
#* Orbit the model by holding down control + wheel.

=== Sketching ===
The sketch function is the most important feature of a CAD program. It allows users to sketch 2D drawings as the base to create 3D objects.

To create a rectangle, first click on “Create Sketch” from the tool bar above. Select the desired sketch plane. In the example above, YZ plane was selected. This is the plane which the 2D sketch will be created. You’ll notice the tool bar above has transformed to display sketch functions. Select “2-Point Rectangle” from the tool bar. Click on the origin of the sketch plane and drag to create a desired rectangle. The sketch features are defined with reference to the origin to position it in space. It is why it is recommended to have one vertex of the sketch to be defined as the origin. After the rectangle is drawn, you can define the dimensions of the 2 sides of the rectangle. You can toggle between the dimensions by using the “Tab” key on your keyboard. Press enter to confirm the sketch.

Next, the line tool will be introduced. Drawing a line is the most simple and versatile function of sketch. It will allow you to create any shapes you will need. Select the “Line” option from the tool bar. Hover your mouse over the rectangle, the mouse will be drawn to the line and an ‘X’ will appear. This means that one end of the line will intersect with the rectangle. Move the mouse towards the middle of the line on the rectangle until a triangle icon shows up. This signifies the midpoint of the line. Click to create the start of the line segment. Drag the mouse to create the line and click again to create the end of the line. You can also manipulate the dimension of the line manually by entering the value.

To draw the line at an angle, drag the line out at an angle. At this point, there should be an angle dimension displayed. This value can be altered manually.

To create an arc, select “Create” -> “Arc” -> “Tangent Arc” from the tool bar. This will create an arc tangent to two other entities. Left click on the vertex of where you would like the arc to connect. Then click on the other vertex to connect. Alternative to create arcs include 3<ins>-</ins> point arcs where you select the two vertex and the middle point of the arc or center point arc when the arc is create<ins>d</ins> by finding the center of the arc.

In order for a 2D sketch to be converted to 3D model, the 2D profile has to be a closed shape. This means all the lines and entities have to form a closed loop. This will be indicated with a light-blue shading inside the sketch.

=== Extrusion ===
The simplest way to create a 3D model is by extruding a 2D sketch, which adds a third dimension to the 2D sketch. Select “Extrude” from the toolbar. Hover the mouse over the sketch, closed shapes that can be extruded will be highlighted when hovered on. To select multiple shapes, left click on both shapes. In the extrusion settings that pops up on the right, enter the value for the third dimension of the sketch, the width. Click “OK” to confirm the extrusion.

You can select a new surface from the extruded object to sketch on. To do so, select “Create Sketch” and select the surface you would like to sketch on as the plane. Afterwards continue to sketch like normal.

Extrusion can also be used to cut. Sketch on the surface of the shape the geometry you would like to cut. Select “Extrude” tool and select the shapes you would like to cut. To remove material, enter a negative value in the dimension window. This indicates the direction you would like the extrusion to occur. On the screen, it will display a red region to indicate material removal. Press enter to confirm the operation.

=== Mirror ===
The mirror tool is an extremely powerful tool that can save the user a lot of time in creating the 3D models. This is especially useful when creating symmetrical objects. It allows users to mirror solid or small features. It does require the user to define the plane to mirror the features. There are many ways to create the plane. One of which is to “Offset Plane”

Under the “Construct” drop-down menu from the toolbar, select “Offset Plane”. Select a surface to offset from. This surface should be parallel from the plane you would like to create. Now enter the dimension you would like to offset the plane from the surface. Press enter when completed.

After the plane has been created, you can now mirror the features. Select “Mirror” under the drop<ins>-</ins> down menu from “Create” from the toolbar. Under “Type” parameter, you can select bodies, faces, features, or components. After the type has been selected, click on “Select” by Object and then the features you would like to mirror, you can also click on the features from the design history timeline. Then click on “Select” by Mirror Plane and the plane you would to mirror from. Now a preview will be displayed<ins>,</ins> to confirm press enter.

=== Fillet ===
Filleting the edges is a feature that is offered in Fusion 360 and not TinkerCAD. It can easily elevate your models. It creates rounded surfaces by adding or removing from a solid model.

# Select “Fillet” under the modify menu from the tool bar.
# Click on the edges you would like to round out.
# Enter a radius value to round the edges out to.
# Click “OK” to finalize.

== References ==
<references />

File:OBJ file .png

2023-08-25T16:31:31Z

Cecilial:

OBJ files curves

File:STL orientation rule.png

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Cecilial:

STL orientation rule

File:STL tessellation .png

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Cecilial:

STL tessellation formats

File:Vector coordinates of STL format.png

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Cecilial:

STL vector

File:STL format.png

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Cecilial:

STL format

File:3D printed surface .png

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Cecilial:

3D printed surface

File:Details on 3D prints.png

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Cecilial:

Details on 3D prints

File:Layers printed in different axis.png

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Cecilial:

Layers strength

File:Holes printed vertically and horizontally..png

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Cecilial:

3D printed holes

File:Supports under floating parts.png

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Cecilial:

3D printed gears with supports

File:Prints in different orientation.png

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Cecilial:

Traffic cone printed in two different orientations

File:Multiple parts 3D print.png

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Cecilial:

3D print hand

File:Heart Button Hole.png

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Cecilial:

Heart Button Hole

Digital technologies/3D printing/3D modeling- Intermediate

2023-08-24T15:26:33Z

Cecilial: /* Complex Shapes in TinkerCAD */

TinkerCAD is nice for smaller parts with very little complexity. However, since it is not [https://en.wikipedia.org/wiki/Non-uniform_rational_B-spline NURBS] based nor parametric, it lacks major functionality. It is strongly suggested at this stage that TinkerCAD, Blender, Cinema 4D or other [https://en.wikipedia.org/wiki/Polygonal_modeling polygonal modelling] (non-NURBS) applications be set aside for parametric CAD software, such as [https://www.autodesk.ca/en/products/fusion-360 Autodesk Fusion 360] ([https://www.autodesk.ca/en/products/fusion-360/students-teachers-educators free for students. teachers, and educators]), [https://www.solidworks.com/ Dassault Systèmes Solidworks] (available through Remote Apps) or [https://www.onshape.com/en/ PTC OnShape] (completely online, free for students and educators) be used for mechanical design, as models made with such software contain much richer data that allows going from CAD models to manufacturing data. Polygonal modelling remains, however, an important tool for Scan to CAD, and such the intermediate CAD user should have a complete understanding of polygonal modelling software such as TinkerCAD.

==[[Digital technologies/3D printing/3D modeling- Intermediate/TinkerCAD (contd.)|Complex Shapes in TinkerCAD]]==
[[File:Heart Button TinkerCAD.png|left|thumb|Heart button CAD model|200x200px]]
In the beginner section of 3D modeling, you learned how to group shapes together. In advanced TinkerCAD, you will use the skills you have gained to create more complex shapes. TinkerCAD provides you with basic geometries such as cubes and cylinders. You can combine these shapes to create more complex geometries such as a house using the group function. To create even more complicated designs, you can combine shapes to be used to create complex holes

The example below will walk you through the making of a heart button. It will involve grouping shapes together in order to create a more complex shape and feature
[[File:Heart_Button_Construction.png|alt=|thumb|351x351px|Combining simple shapes like cylinders and cubes to create heart shape. ]]
# Add a box shape to the workspace. Make sure the dimension of the box has the thickness of the desired button. This will serve as the point of the heart.
# Add two cylinders with the same thickness as the box to two edges of the box. Set the diameter of the cylinder as the width of the box. This will create the humps of the heart.
# Using the round roof object, size it to the appropriate dimension for the button hoop.
# Copy and paste<s>r</s> a second round roof object and make it slightly smaller to be used to create the hole for the button hoop.
# Turn the object into a hole and position it accordingly.
# Finally, group the shapes together and the button is completed.

== [[Digital technologies/3D printing/3D modeling- Intermediate/Design for 3D Printing|Design for 3D Printing]] ==
There are some important things to note when modeling for 3D printing. It is important to optimize the print by decreasing print time and material while ensuring accuracy and strength of the part.

# Divide your model into smaller more manageable parts. There are many designs with complex details or large dimensions that would be more manageable prints if split into multiple parts
# Try to ensure that there is one flat surface on the print. This will allow easier print set-up. The flat side can adhere to the build plate, minimizing the need for additional build plate adhesion.
# Avoid floating parts. All aspect of the model should be connected to the main model. Minimize overhangs in the model as well. This will prevent wasted time and material to print supports.
# FDM printing has limited capabilities with dimensional accuracy. It is recommended to prevent printing horizontally oriented holes of the smaller size. These holes are often deformed and printed with difficult to remove supports.
# Printed parts are stronger in one direction than another. It is important to keep this in mind when designing. Prints will be weaker in the areas where the layers meet. This means that printed parts have low tensile strength along the Z-axis. The prints will be the strongest in planes parallel to the build surface.
# Exaggerate the details of your designs. This is an important thing to keep in mind. In order for details to show up on small designs, you should make your cuts deeper and bigger. It can also be helpful to make slender designs thicker.
# Exaggerate the details of your designs. This is an important thing to keep in mind. In order for details to show up on small designs, you should make your cuts deeper and bigger. It can also be helpful to make slender designs thicker.
#

If your design is to be used in (electro-)mechanical assemblies in which there are interfacing components, it is important that you understand three basic tolerancing concepts and to keep them in the back of your mind when modeling or more generally designing these assemblies.

# Form: The form of a part refers to the overall dimensions and the shape of the exterior surfaces of a component. Think of a flaw referring to form as a print that ended up not matching the base geometry that was used to create it in CAD due to adverse physical variables during the printing process. Examples follow:
## A ''sphere'' may end up slightly ''oval'' once printed due to improper cooling, etc.;
## A pillar might end up tilted to one side due to improper belt tension between the belt axes, etc.;
## A pin feature might end up too large to fit its mating hole due to the printer outputting too much material when producing the outer walls of the feature (the inverse can also be true).
# Position: Position refers to the distance separating a feature and an (ideally) meaningful reference (i.e.: the distance between a hole and the side of a part, or between two holes). Thankfully, flaws pertaining to position are rare on a properly tuned printer, as the printer does not have any information about existing references other than the build plate. If tuned properly, the printer will always print a feature at a position (X,Y,Z) distance relative to another feature, because that is what the gCode will tell it to do. You can imagine, however, that if the part is warped, the 'build plate reference' is no longer valid, and such, warped parts almost always have features out of position ''unless the meaningful reference (interfacing feature) used in the design is not the build plate''. However, since the build plate reference is such an important one to define the Z position of features (for the printer, that is), making your meaningful reference something other than the build plate does not always guarantee you good positional tolerance independent of warping.
# Surface: The surface finish of a part is a rather complex subject. In 3D printing, and for typical applications of 3D printed parts, it mostly refers to the mean (statistical) difference between the height of cusps and valleys on a part and their deviation from that mean, at a macroscopic level. The most important consideration is that when 3D printing, most surface finishes are quite rough (deviate significantly from the mean), and thus are sanded down considerably to knock out the cusps left by the printer. This post processing can negatively affect the form of the final part.

Note that ''a proper mechanical fit between components demands a good tolerance on form, feature position, and surface finish'', such that it is typically impossible to obtain a proper fit when 3D printing, and that if you are considering the 3D printing of critically interfacing components, 3D printing should not be used unless post processing ''is built into the design''. For mechanical designs, you will notice that a main application is brackets. This is because brackets only need good positional tolerance on holes and mating faces, which 3D printing can almost always provide (the tolerance on form for holes is not that important since they are typically clearance holes). However, since some brackets are easily laser cut, 3D printing brackets is only done under certain specific conditions. It certainly has shown its commercial use in cost cutting by replacing intricate multi-part assemblies by ''generatively designed'' (we'll say computer generated for now) parts, as shown in the picture below.
[[File:Design for 3D Printing Generatively Designed Bracket.jpg|center|thumb|600x600px|A metal 3D printed generatively designed bracket (computer generated from load data, using Finite Element Analysis), likely replacing a multitude of other parts that would have been manufactured using traditional manufacturing methods which would lead to a heavier and more expensive bracket.<ref>CarrusHome (2021). GM Explores 3D printing, generative design for next gen parts. Consulted on 05-05-2022 at <nowiki>https://www.carrushome.com/en/gm-explores-3d-printing-generative-design-for-next-gen-parts/</nowiki></ref>]]

==[[Digital technologies/3D printing/3D modeling- Intermediate/CAD Extensions|CAD File Formats]] ==
In the beginner section of 3D modeling, you were introduced to TinkerCAD. In the instructions, you were instructed to export your 3D designs as a STL or OBJ file. In this section, the differences between different CAD file formats will be discussed.

=== [https://en.wikipedia.org/wiki/STL_(file_format) Standard Triangle Language (*.STL)] ===
STL files are the most used file format in 3D printing and 3D modeling. Most 3D printers support the file format. Many of the 3D printable models online are also found in STL file format. STL stands for stereolithography, a 3D printing process created at 3D Systems in <ins>the </ins>1980s. STL file format encodes the surface geometry of a 3D object. This is done through tessellation, a process of tiling a surface with one or more geometric shapes so there are no overlaps or gaps. The basic method of tessellating the outer surface of 3D models is through the use of tiny triangles (called “facets”) and store information about the facets in a file. For example, in the figure below, it shows how a cube can be represented by 12 triangles while 17000+ triangles are needed to represent a sphere. Since triangles consist of three straight edges, it can be difficult to approximate curved geometries. To do so, mesh density is increased, and individual triangle’s size is decreased.

STL file format stores the information as the coordinates of the vertices and the components of the unit normal vector to the triangle. The normal vector point outwards of the 3D model.

There are a couple of rules for tessellation and storing information. The vertex rule states that each triangle must share two vertices with its neighbouring triangles.

The orientation rule states that the orientation of the facet must be specified in two ways. The direction of the normal should point outwards, and the vertices are listed in counter-clockwise when looking at the object from the outside.

The all-positive octant rule states that the coordinates of the triangle vertices must all be positive. This ensures that all coordinates stored would be in the positive which would save space in the file. Finally, the triangle sorting rule recommends that the triangles appear in ascending z-value order. This is a recommendation rather than a rule as it helps the software slice the models faster.

=== [https://en.wikipedia.org/wiki/Wavefront_.obj_file Wavefront OBJ (*.OBJ)] ===
OBJ is a crucial file format in 3D printing. It is generally preferred for multi-colour 3D printing. Often, it is used a s an interchange format for non-animated 3D models. OBJ file format stores information about 3D models by encoding the surface geometry of the model. It also stores information about its colour and texture. It does not store any data about animations or scene. It is open source and neutral. Therefore, it is often used to share 3D models since many CAD software supports the format.

It differs from STL since it stores colour and texture information. STL is an older file format that is missing modern features. It does not support multi colour printing or high resolution prints. OBJ can approximate surface geometry well without drastically increasing the file size. It also supports multiple colours and textures in the same model.

OBJ encodes surface geometry of a 3D object in many different methods: Tessellation with polygonal faces, freeform curves and freeform surfaces. Similar to STL, OBJ allows tessellation of the surfaces with simple geometric shapes like triangles or more complex polygon. This is the simplest way to describe surface geometry. However, approximating curved surfaces with polygons will introduce coarseness and geometric deviation from the model. The size of the polygons can be decreased to increase the quality of the prints. However, this can lead to giant file sizes which can be difficult for 3D printers to handle. It is important to find the right balance between print quality and file sizes.

The surface geometry can also be defined using freeform curves. The user defines a collection of free form curves that runs along the surface of the model. The surface is then approximated using the collection of curves. It is more complicated than polygonal faces, but it allows for fewer data to describe the same surface. The curved lines can be described using freeform curves with a few mathematical parameters. It allows for higher quality encoding without drastically increasing the file size.

=== DS Solidworks Parts (*.SLDPRT) and DS Solidworks Assemblies (*.SLDASM) ===
Sldprt file formats are native SolidWorks file extensions. It provides details on specific parts within a system. This is a software specific file format. Opening SolidWorks files in slicers and other software may cause some corruption of your designs. However, because it is software specific, it contains the most information about your models. As such, you should do all your modeling while the files are in native format

=== [https://en.wikipedia.org/wiki/ISO_10303 ISO10303 - Standard for the Exchange of Product model data (*.STP, *.STEP)] ===
STEP file format is a neutral file format. It is the most common file format used to share 3D designs. This allows users to open others’ designs using the software of their choice. It stores 3D images in an ASCII format. While STEP files can be opened with most CAD software. It is not easily edited. The model will display as a finalized object. Users cannot edit specific dimensions or features of the model.

===Polygonal Formats===

*[https://en.wikipedia.org/wiki/STL_(file_format) Standard Triangle Language (*.STL)]
*[https://en.wikipedia.org/wiki/Wavefront_.obj_file Wavefront OBJ (*.OBJ)]
*[https://en.wikipedia.org/wiki/3D_Manufacturing_Format 3D Manufacturing Format (*.3MF)]

===NURBS Formats===

====Standard====

*[https://en.wikipedia.org/wiki/ISO_10303 ISO10303 - Standard for the Exchange of Product model data (*.STP, *.STEP)]
*[https://en.wikipedia.org/wiki/AutoCAD_DXF AutoCAD Drawing Exchange Format (*.DXF/*.DWG)]
*[https://en.wikipedia.org/wiki/IGES Initial Graphics Exchange Specification (*.IGES)] (standard last updated 1996)

====Software-Specific====

*DS Solidworks Parts (*.SLDPRT)
*DS Solidworks Assemblies (*.SLDASM)
*DS CATIA V5 Parts (*.CGR/*.CATPart)
*DS CATIA V5 Assemblies (*.CGR/*.CATProduct)
*PTC Creo Parts (*.PRT)
*PTC Creo Assemblies (*.ASM)

*Fusion 360 (*.F3D)

It should be noted that Fusion360 stores files on the cloud, such that locally saved .f3d files are not commonly encountered. It should also be noted that OnShape does not have a file format given it is hosted entirely on the cloud.

==[[Digital technologies/3D printing/3D modeling- Intermediate/Using Parametric NURBS Software|Introduction to Fusion360]]==
TinkerCAD is known for its simplicity, meaning it is easy to learn and use. However, its capabilities are limited. It uses a drag and drop method to create basic geometries. Theses shapes can be grouped to create more complex geometries but it takes more time to design something complex and has less flexibility. Fusion<ins> </ins>360 is a sketch-based CAD modeling software that allows for users to completely customize their design. It allows users to design 3D objects using 2D sketches.

Fusion 360 offers 3D CAD modeling, PCB design, and 3D simulation capabilities. It is a fee-based subscription software, however, a free version is offered for personal use. The free version has some limited capabilities but most of the 3D CAD features are offered. Even with the limited features it offers more design options than TinkerCAD. To download the software, you can use your AutoCAD account and follow the link below: <nowiki>https://www.autodesk.ca/en/products/fusion-360/personal</nowiki>

Just like TinkerCAD, and with any CAD modeling software you choose to use<ins>,</ins><s>. Y</s><ins> y</ins>ou can export your part designs as an STL file. Using this file format, you can use any slicer of your choice to slice the design into a gcode file to print.

=== Fusion 360 User Interface ===
There are 5 main areas of the user interface. When the software is first launched, you should be seeing the screen above.

# Data Panel: On the left is the data panel. It displays pinned and recent projects, providing easy access to these projects for the users. It will also display sample projects that corresponds to the tutorials offered by AutoCAD. Users can also upload their projects to be shared with others for collaboration.
# Tool Bar: On the top of the screen sits the tool bar. Through this, you can use any of the features displayed to manipulate the 3D model you create. The shortcuts can be customized to display the ones you favour.
# Browser: Located at the top left of the main screen. It displays the model design with a file tree structure listing all the components, bodies and constructing plane. The files can be navigated through by clicking on their names. They can also be renamed by double clicking. The files can be collapsed using the triangles. The visibility of the bodies and planes can be toggled by clicking on the lightbulb.
# Timeline: The timeline of the design history is displayed at the bottom of the screen. This is a special feature of Fusion<ins> </ins>360 that is different from other CAD software. It keeps a record of the construction of the 3D model allowing the users to playback the building of the model. This feature also allow<ins>s</ins> users to add to the model from a previous state of the model.
# Navigation bar: The navigation bard allows users to change the view of the model. These features exist<s>s</s> as shortcuts when used with a mouse. For this reason, it is recommended to create CAD models using a physical mouse instead of a track pad. Some features include:
#* Zoom In/Out by scrolling up/down with the mouse.
#* Pan the model by holding down the wheel of the mouse.
#* Orbit the model by holding down control + wheel.

=== Sketching ===
The sketch function is the most important feature of a CAD program. It allows users to sketch 2D drawings as the base to create 3D objects.

To create a rectangle, first click on “Create Sketch” from the tool bar above. Select the desired sketch plane. In the example above, YZ plane was selected. This is the plane which the 2D sketch will be created. You’ll notice the tool bar above has transformed to display sketch functions. Select “2-Point Rectangle” from the tool bar. Click on the origin of the sketch plane and drag to create a desired rectangle. The sketch features are defined with reference to the origin to position it in space. It is why it is recommended to have one vertex of the sketch to be defined as the origin. After the rectangle is drawn, you can define the dimensions of the 2 sides of the rectangle. You can toggle between the dimensions by using the “Tab” key on your keyboard. Press enter to confirm the sketch.

Next, the line tool will be introduced. Drawing a line is the most simple and versatile function of sketch. It will allow you to create any shapes you will need. Select the “Line” option from the tool bar. Hover your mouse over the rectangle, the mouse will be drawn to the line and an ‘X’ will appear. This means that one end of the line will intersect with the rectangle. Move the mouse towards the middle of the line on the rectangle until a triangle icon shows up. This signifies the midpoint of the line. Click to create the start of the line segment. Drag the mouse to create the line and click again to create the end of the line. You can also manipulate the dimension of the line manually by entering the value.

To draw the line at an angle, drag the line out at an angle. At this point, there should be an angle dimension displayed. This value can be altered manually.

To create an arc, select “Create” -> “Arc” -> “Tangent Arc” from the tool bar. This will create an arc tangent to two other entities. Left click on the vertex of where you would like the arc to connect. Then click on the other vertex to connect. Alternative to create arcs include 3<ins>-</ins> point arcs where you select the two vertex and the middle point of the arc or center point arc when the arc is create<ins>d</ins> by finding the center of the arc.

In order for a 2D sketch to be converted to 3D model, the 2D profile has to be a closed shape. This means all the lines and entities have to form a closed loop. This will be indicated with a light-blue shading inside the sketch.

=== Extrusion ===
The simplest way to create a 3D model is by extruding a 2D sketch, which adds a third dimension to the 2D sketch. Select “Extrude” from the toolbar. Hover the mouse over the sketch, closed shapes that can be extruded will be highlighted when hovered on. To select multiple shapes, left click on both shapes. In the extrusion settings that pops up on the right, enter the value for the third dimension of the sketch, the width. Click “OK” to confirm the extrusion.

You can select a new surface from the extruded object to sketch on. To do so, select “Create Sketch” and select the surface you would like to sketch on as the plane. Afterwards continue to sketch like normal.

Extrusion can also be used to cut. Sketch on the surface of the shape the geometry you would like to cut. Select “Extrude” tool and select the shapes you would like to cut. To remove material, enter a negative value in the dimension window. This indicates the direction you would like the extrusion to occur. On the screen, it will display a red region to indicate material removal. Press enter to confirm the operation.

=== Mirror ===
The mirror tool is an extremely powerful tool that can save the user a lot of time in creating the 3D models. This is especially useful when creating symmetrical objects. It allows users to mirror solid or small features. It does require the user to define the plane to mirror the features. There are many ways to create the plane. One of which is to “Offset Plane”

Under the “Construct” drop-down menu from the toolbar, select “Offset Plane”. Select a surface to offset from. This surface should be parallel from the plane you would like to create. Now enter the dimension you would like to offset the plane from the surface. Press enter when completed.

After the plane has been created, you can now mirror the features. Select “Mirror” under the drop<ins>-</ins> down menu from “Create” from the toolbar. Under “Type” parameter, you can select bodies, faces, features, or components. After the type has been selected, click on “Select” by Object and then the features you would like to mirror, you can also click on the features from the design history timeline. Then click on “Select” by Mirror Plane and the plane you would to mirror from. Now a preview will be displayed<ins>,</ins> to confirm press enter.

=== Fillet ===
Filleting the edges is a feature that is offered in Fusion 360 and not TinkerCAD. It can easily elevate your models. It creates rounded surfaces by adding or removing from a solid model.

# Select “Fillet” under the modify menu from the tool bar.
# Click on the edges you would like to round out.
# Enter a radius value to round the edges out to.
# Click “OK” to finalize.

== References ==
<references />

Digital technologies/3D printing/3D modeling- Intermediate

2023-08-24T15:01:24Z

Cecilial: /* Complex Shapes in TinkerCAD */

TinkerCAD is nice for smaller parts with very little complexity. However, since it is not [https://en.wikipedia.org/wiki/Non-uniform_rational_B-spline NURBS] based nor parametric, it lacks major functionality. It is strongly suggested at this stage that TinkerCAD, Blender, Cinema 4D or other [https://en.wikipedia.org/wiki/Polygonal_modeling polygonal modelling] (non-NURBS) applications be set aside for parametric CAD software, such as [https://www.autodesk.ca/en/products/fusion-360 Autodesk Fusion 360] ([https://www.autodesk.ca/en/products/fusion-360/students-teachers-educators free for students. teachers, and educators]), [https://www.solidworks.com/ Dassault Systèmes Solidworks] (available through Remote Apps) or [https://www.onshape.com/en/ PTC OnShape] (completely online, free for students and educators) be used for mechanical design, as models made with such software contain much richer data that allows going from CAD models to manufacturing data. Polygonal modelling remains, however, an important tool for Scan to CAD, and such the intermediate CAD user should have a complete understanding of polygonal modelling software such as TinkerCAD.

==[[Digital technologies/3D printing/3D modeling- Intermediate/TinkerCAD (contd.)|Complex Shapes in TinkerCAD]]==
[[File:Heart Button TinkerCAD.png|left|thumb|Heart button CAD model|200x200px]]
In the beginner section of 3D modeling, you learned how to group shapes together. In advanced TinkerCAD, you will use the skills you have gained to create more complex shapes. TinkerCAD provides you with basic geometries such as cubes and cylinders. You can combine these shapes to create more complex geometries such as a house using the group function. To create even more complicated designs, you can combine shapes to be used to create complex holes

The example below will walk you through the making of a heart button. It will involve grouping shapes together in order to create a more complex shape and feature
[[File:Heart_Button_Construction.png|alt=|thumb|351x351px|Combining simple shapes like cylinders and cubes to create heart shape. ]]
# Add a box shape to the workspace. Make sure the dimension of the box has the thickness of the desired button. This will serve as the point of the heart.
# Add two cylinders with the same thickness as the box to two edges of the box. Set the diameter of the cylinder as the width of the box. This will create the humps of the heart.
# Using the round roof object, size it to the appropriate dimension for the button hoop.
# Copy and paste<s>r</s> a second round roof object and make it slightly smaller to be used to create the hole for the button hoop.
# Turn the object into a hole and position it accordingly.
# Finally, group the shapes together and the button is completed.

== [[Digital technologies/3D printing/3D modeling- Intermediate/Design for 3D Printing|Design for 3D Printing]] ==
There are some important things to note when modeling for 3D printing. It is important to optimize the print by decreasing print time and material while ensuring accuracy and strength of the part.

# Divide your model into smaller more manageable parts. There are many designs with complex details or large dimensions that would be more manageable prints if split into multiple parts
# Try to ensure that there is one flat surface on the print. This will allow easier print set-up. The flat side can adhere to the build plate, minimizing the need for additional build plate adhesion.
# Avoid floating parts. All aspect of the model should be connected to the main model. Minimize overhangs in the model as well. This will prevent wasted time and material to print supports.
# FDM printing has limited capabilities with dimensional accuracy. It is recommended to prevent printing horizontally oriented holes of the smaller size. These holes are often deformed and printed with difficult to remove supports.
# Printed parts are stronger in one direction than another. It is important to keep this in mind when designing. Prints will be weaker in the areas where the layers meet. This means that printed parts have low tensile strength along the Z-axis. The prints will be the strongest in planes parallel to the build surface.
# Exaggerate the details of your designs. This is an important thing to keep in mind. In order for details to show up on small designs, you should make your cuts deeper and bigger. It can also be helpful to make slender designs thicker.
# Exaggerate the details of your designs. This is an important thing to keep in mind. In order for details to show up on small designs, you should make your cuts deeper and bigger. It can also be helpful to make slender designs thicker.
#

If your design is to be used in (electro-)mechanical assemblies in which there are interfacing components, it is important that you understand three basic tolerancing concepts and to keep them in the back of your mind when modeling or more generally designing these assemblies.

# Form: The form of a part refers to the overall dimensions and the shape of the exterior surfaces of a component. Think of a flaw referring to form as a print that ended up not matching the base geometry that was used to create it in CAD due to adverse physical variables during the printing process. Examples follow:
## A ''sphere'' may end up slightly ''oval'' once printed due to improper cooling, etc.;
## A pillar might end up tilted to one side due to improper belt tension between the belt axes, etc.;
## A pin feature might end up too large to fit its mating hole due to the printer outputting too much material when producing the outer walls of the feature (the inverse can also be true).
# Position: Position refers to the distance separating a feature and an (ideally) meaningful reference (i.e.: the distance between a hole and the side of a part, or between two holes). Thankfully, flaws pertaining to position are rare on a properly tuned printer, as the printer does not have any information about existing references other than the build plate. If tuned properly, the printer will always print a feature at a position (X,Y,Z) distance relative to another feature, because that is what the gCode will tell it to do. You can imagine, however, that if the part is warped, the 'build plate reference' is no longer valid, and such, warped parts almost always have features out of position ''unless the meaningful reference (interfacing feature) used in the design is not the build plate''. However, since the build plate reference is such an important one to define the Z position of features (for the printer, that is), making your meaningful reference something other than the build plate does not always guarantee you good positional tolerance independent of warping.
# Surface: The surface finish of a part is a rather complex subject. In 3D printing, and for typical applications of 3D printed parts, it mostly refers to the mean (statistical) difference between the height of cusps and valleys on a part and their deviation from that mean, at a macroscopic level. The most important consideration is that when 3D printing, most surface finishes are quite rough (deviate significantly from the mean), and thus are sanded down considerably to knock out the cusps left by the printer. This post processing can negatively affect the form of the final part.

Note that ''a proper mechanical fit between components demands a good tolerance on form, feature position, and surface finish'', such that it is typically impossible to obtain a proper fit when 3D printing, and that if you are considering the 3D printing of critically interfacing components, 3D printing should not be used unless post processing ''is built into the design''. For mechanical designs, you will notice that a main application is brackets. This is because brackets only need good positional tolerance on holes and mating faces, which 3D printing can almost always provide (the tolerance on form for holes is not that important since they are typically clearance holes). However, since some brackets are easily laser cut, 3D printing brackets is only done under certain specific conditions. It certainly has shown its commercial use in cost cutting by replacing intricate multi-part assemblies by ''generatively designed'' (we'll say computer generated for now) parts, as shown in the picture below.
[[File:Design for 3D Printing Generatively Designed Bracket.jpg|center|thumb|600x600px|A metal 3D printed generatively designed bracket (computer generated from load data, using Finite Element Analysis), likely replacing a multitude of other parts that would have been manufactured using traditional manufacturing methods which would lead to a heavier and more expensive bracket.<ref>CarrusHome (2021). GM Explores 3D printing, generative design for next gen parts. Consulted on 05-05-2022 at <nowiki>https://www.carrushome.com/en/gm-explores-3d-printing-generative-design-for-next-gen-parts/</nowiki></ref>]]

==[[Digital technologies/3D printing/3D modeling- Intermediate/CAD Extensions|CAD File Formats]] ==
In the beginner section of 3D modeling, you were introduced to TinkerCAD. In the instructions, you were instructed to export your 3D designs as a STL or OBJ file. In this section, the differences between different CAD file formats will be discussed.

=== [https://en.wikipedia.org/wiki/STL_(file_format) Standard Triangle Language (*.STL)] ===
STL files are the most used file format in 3D printing and 3D modeling. Most 3D printers support the file format. Many of the 3D printable models online are also found in STL file format. STL stands for stereolithography, a 3D printing process created at 3D Systems in <ins>the </ins>1980s. STL file format encodes the surface geometry of a 3D object. This is done through tessellation, a process of tiling a surface with one or more geometric shapes so there are no overlaps or gaps. The basic method of tessellating the outer surface of 3D models is through the use of tiny triangles (called “facets”) and store information about the facets in a file. For example, in the figure below, it shows how a cube can be represented by 12 triangles while 17000+ triangles are needed to represent a sphere. Since triangles consist of three straight edges, it can be difficult to approximate curved geometries. To do so, mesh density is increased, and individual triangle’s size is decreased.

STL file format stores the information as the coordinates of the vertices and the components of the unit normal vector to the triangle. The normal vector point outwards of the 3D model.

There are a couple of rules for tessellation and storing information. The vertex rule states that each triangle must share two vertices with its neighbouring triangles.

The orientation rule states that the orientation of the facet must be specified in two ways. The direction of the normal should point outwards, and the vertices are listed in counter-clockwise when looking at the object from the outside.

The all-positive octant rule states that the coordinates of the triangle vertices must all be positive. This ensures that all coordinates stored would be in the positive which would save space in the file. Finally, the triangle sorting rule recommends that the triangles appear in ascending z-value order. This is a recommendation rather than a rule as it helps the software slice the models faster.

=== [https://en.wikipedia.org/wiki/Wavefront_.obj_file Wavefront OBJ (*.OBJ)] ===
OBJ is a crucial file format in 3D printing. It is generally preferred for multi-colour 3D printing. Often, it is used a s an interchange format for non-animated 3D models. OBJ file format stores information about 3D models by encoding the surface geometry of the model. It also stores information about its colour and texture. It does not store any data about animations or scene. It is open source and neutral. Therefore, it is often used to share 3D models since many CAD software supports the format.

It differs from STL since it stores colour and texture information. STL is an older file format that is missing modern features. It does not support multi colour printing or high resolution prints. OBJ can approximate surface geometry well without drastically increasing the file size. It also supports multiple colours and textures in the same model.

OBJ encodes surface geometry of a 3D object in many different methods: Tessellation with polygonal faces, freeform curves and freeform surfaces. Similar to STL, OBJ allows tessellation of the surfaces with simple geometric shapes like triangles or more complex polygon. This is the simplest way to describe surface geometry. However, approximating curved surfaces with polygons will introduce coarseness and geometric deviation from the model. The size of the polygons can be decreased to increase the quality of the prints. However, this can lead to giant file sizes which can be difficult for 3D printers to handle. It is important to find the right balance between print quality and file sizes.

The surface geometry can also be defined using freeform curves. The user defines a collection of free form curves that runs along the surface of the model. The surface is then approximated using the collection of curves. It is more complicated than polygonal faces, but it allows for fewer data to describe the same surface. The curved lines can be described using freeform curves with a few mathematical parameters. It allows for higher quality encoding without drastically increasing the file size.

=== DS Solidworks Parts (*.SLDPRT) and DS Solidworks Assemblies (*.SLDASM) ===
Sldprt file formats are native SolidWorks file extensions. It provides details on specific parts within a system. This is a software specific file format. Opening SolidWorks files in slicers and other software may cause some corruption of your designs. However, because it is software specific, it contains the most information about your models. As such, you should do all your modeling while the files are in native format

=== [https://en.wikipedia.org/wiki/ISO_10303 ISO10303 - Standard for the Exchange of Product model data (*.STP, *.STEP)] ===
STEP file format is a neutral file format. It is the most common file format used to share 3D designs. This allows users to open others’ designs using the software of their choice. It stores 3D images in an ASCII format. While STEP files can be opened with most CAD software. It is not easily edited. The model will display as a finalized object. Users cannot edit specific dimensions or features of the model.

===Polygonal Formats===

*[https://en.wikipedia.org/wiki/STL_(file_format) Standard Triangle Language (*.STL)]
*[https://en.wikipedia.org/wiki/Wavefront_.obj_file Wavefront OBJ (*.OBJ)]
*[https://en.wikipedia.org/wiki/3D_Manufacturing_Format 3D Manufacturing Format (*.3MF)]

===NURBS Formats===

====Standard====

*[https://en.wikipedia.org/wiki/ISO_10303 ISO10303 - Standard for the Exchange of Product model data (*.STP, *.STEP)]
*[https://en.wikipedia.org/wiki/AutoCAD_DXF AutoCAD Drawing Exchange Format (*.DXF/*.DWG)]
*[https://en.wikipedia.org/wiki/IGES Initial Graphics Exchange Specification (*.IGES)] (standard last updated 1996)

====Software-Specific====

*DS Solidworks Parts (*.SLDPRT)
*DS Solidworks Assemblies (*.SLDASM)
*DS CATIA V5 Parts (*.CGR/*.CATPart)
*DS CATIA V5 Assemblies (*.CGR/*.CATProduct)
*PTC Creo Parts (*.PRT)
*PTC Creo Assemblies (*.ASM)

*Fusion 360 (*.F3D)

It should be noted that Fusion360 stores files on the cloud, such that locally saved .f3d files are not commonly encountered. It should also be noted that OnShape does not have a file format given it is hosted entirely on the cloud.

==[[Digital technologies/3D printing/3D modeling- Intermediate/Using Parametric NURBS Software|Introduction to Fusion360]]==
TinkerCAD is known for its simplicity, meaning it is easy to learn and use. However, its capabilities are limited. It uses a drag and drop method to create basic geometries. Theses shapes can be grouped to create more complex geometries but it takes more time to design something complex and has less flexibility. Fusion<ins> </ins>360 is a sketch-based CAD modeling software that allows for users to completely customize their design. It allows users to design 3D objects using 2D sketches.

Fusion 360 offers 3D CAD modeling, PCB design, and 3D simulation capabilities. It is a fee-based subscription software, however, a free version is offered for personal use. The free version has some limited capabilities but most of the 3D CAD features are offered. Even with the limited features it offers more design options than TinkerCAD. To download the software, you can use your AutoCAD account and follow the link below: <nowiki>https://www.autodesk.ca/en/products/fusion-360/personal</nowiki>

Just like TinkerCAD, and with any CAD modeling software you choose to use<ins>,</ins><s>. Y</s><ins> y</ins>ou can export your part designs as an STL file. Using this file format, you can use any slicer of your choice to slice the design into a gcode file to print.

=== Fusion 360 User Interface ===
There are 5 main areas of the user interface. When the software is first launched, you should be seeing the screen above.

# Data Panel: On the left is the data panel. It displays pinned and recent projects, providing easy access to these projects for the users. It will also display sample projects that corresponds to the tutorials offered by AutoCAD. Users can also upload their projects to be shared with others for collaboration.
# Tool Bar: On the top of the screen sits the tool bar. Through this, you can use any of the features displayed to manipulate the 3D model you create. The shortcuts can be customized to display the ones you favour.
# Browser: Located at the top left of the main screen. It displays the model design with a file tree structure listing all the components, bodies and constructing plane. The files can be navigated through by clicking on their names. They can also be renamed by double clicking. The files can be collapsed using the triangles. The visibility of the bodies and planes can be toggled by clicking on the lightbulb.
# Timeline: The timeline of the design history is displayed at the bottom of the screen. This is a special feature of Fusion<ins> </ins>360 that is different from other CAD software. It keeps a record of the construction of the 3D model allowing the users to playback the building of the model. This feature also allow<ins>s</ins> users to add to the model from a previous state of the model.
# Navigation bar: The navigation bard allows users to change the view of the model. These features exist<s>s</s> as shortcuts when used with a mouse. For this reason, it is recommended to create CAD models using a physical mouse instead of a track pad. Some features include:
#* Zoom In/Out by scrolling up/down with the mouse.
#* Pan the model by holding down the wheel of the mouse.
#* Orbit the model by holding down control + wheel.

=== Sketching ===
The sketch function is the most important feature of a CAD program. It allows users to sketch 2D drawings as the base to create 3D objects.

To create a rectangle, first click on “Create Sketch” from the tool bar above. Select the desired sketch plane. In the example above, YZ plane was selected. This is the plane which the 2D sketch will be created. You’ll notice the tool bar above has transformed to display sketch functions. Select “2-Point Rectangle” from the tool bar. Click on the origin of the sketch plane and drag to create a desired rectangle. The sketch features are defined with reference to the origin to position it in space. It is why it is recommended to have one vertex of the sketch to be defined as the origin. After the rectangle is drawn, you can define the dimensions of the 2 sides of the rectangle. You can toggle between the dimensions by using the “Tab” key on your keyboard. Press enter to confirm the sketch.

Next, the line tool will be introduced. Drawing a line is the most simple and versatile function of sketch. It will allow you to create any shapes you will need. Select the “Line” option from the tool bar. Hover your mouse over the rectangle, the mouse will be drawn to the line and an ‘X’ will appear. This means that one end of the line will intersect with the rectangle. Move the mouse towards the middle of the line on the rectangle until a triangle icon shows up. This signifies the midpoint of the line. Click to create the start of the line segment. Drag the mouse to create the line and click again to create the end of the line. You can also manipulate the dimension of the line manually by entering the value.

To draw the line at an angle, drag the line out at an angle. At this point, there should be an angle dimension displayed. This value can be altered manually.

To create an arc, select “Create” -> “Arc” -> “Tangent Arc” from the tool bar. This will create an arc tangent to two other entities. Left click on the vertex of where you would like the arc to connect. Then click on the other vertex to connect. Alternative to create arcs include 3<ins>-</ins> point arcs where you select the two vertex and the middle point of the arc or center point arc when the arc is create<ins>d</ins> by finding the center of the arc.

In order for a 2D sketch to be converted to 3D model, the 2D profile has to be a closed shape. This means all the lines and entities have to form a closed loop. This will be indicated with a light-blue shading inside the sketch.

=== Extrusion ===
The simplest way to create a 3D model is by extruding a 2D sketch, which adds a third dimension to the 2D sketch. Select “Extrude” from the toolbar. Hover the mouse over the sketch, closed shapes that can be extruded will be highlighted when hovered on. To select multiple shapes, left click on both shapes. In the extrusion settings that pops up on the right, enter the value for the third dimension of the sketch, the width. Click “OK” to confirm the extrusion.

You can select a new surface from the extruded object to sketch on. To do so, select “Create Sketch” and select the surface you would like to sketch on as the plane. Afterwards continue to sketch like normal.

Extrusion can also be used to cut. Sketch on the surface of the shape the geometry you would like to cut. Select “Extrude” tool and select the shapes you would like to cut. To remove material, enter a negative value in the dimension window. This indicates the direction you would like the extrusion to occur. On the screen, it will display a red region to indicate material removal. Press enter to confirm the operation.

=== Mirror ===
The mirror tool is an extremely powerful tool that can save the user a lot of time in creating the 3D models. This is especially useful when creating symmetrical objects. It allows users to mirror solid or small features. It does require the user to define the plane to mirror the features. There are many ways to create the plane. One of which is to “Offset Plane”

Under the “Construct” drop-down menu from the toolbar, select “Offset Plane”. Select a surface to offset from. This surface should be parallel from the plane you would like to create. Now enter the dimension you would like to offset the plane from the surface. Press enter when completed.

After the plane has been created, you can now mirror the features. Select “Mirror” under the drop<ins>-</ins> down menu from “Create” from the toolbar. Under “Type” parameter, you can select bodies, faces, features, or components. After the type has been selected, click on “Select” by Object and then the features you would like to mirror, you can also click on the features from the design history timeline. Then click on “Select” by Mirror Plane and the plane you would to mirror from. Now a preview will be displayed<ins>,</ins> to confirm press enter.

=== Fillet ===
Filleting the edges is a feature that is offered in Fusion 360 and not TinkerCAD. It can easily elevate your models. It creates rounded surfaces by adding or removing from a solid model.

# Select “Fillet” under the modify menu from the tool bar.
# Click on the edges you would like to round out.
# Enter a radius value to round the edges out to.
# Click “OK” to finalize.

== References ==
<references />

Digital technologies/3D printing/3D modeling- Intermediate

2023-08-24T14:18:05Z

Cecilial:

TinkerCAD is nice for smaller parts with very little complexity. However, since it is not [https://en.wikipedia.org/wiki/Non-uniform_rational_B-spline NURBS] based nor parametric, it lacks major functionality. It is strongly suggested at this stage that TinkerCAD, Blender, Cinema 4D or other [https://en.wikipedia.org/wiki/Polygonal_modeling polygonal modelling] (non-NURBS) applications be set aside for parametric CAD software, such as [https://www.autodesk.ca/en/products/fusion-360 Autodesk Fusion 360] ([https://www.autodesk.ca/en/products/fusion-360/students-teachers-educators free for students. teachers, and educators]), [https://www.solidworks.com/ Dassault Systèmes Solidworks] (available through Remote Apps) or [https://www.onshape.com/en/ PTC OnShape] (completely online, free for students and educators) be used for mechanical design, as models made with such software contain much richer data that allows going from CAD models to manufacturing data. Polygonal modelling remains, however, an important tool for Scan to CAD, and such the intermediate CAD user should have a complete understanding of polygonal modelling software such as TinkerCAD.

==[[Digital technologies/3D printing/3D modeling- Intermediate/TinkerCAD (contd.)|Complex Shapes in TinkerCAD]]==
[[File:Heart Button TinkerCAD.png|left|thumb|Heart button CAD model ]]
In the beginner section of 3D modeling, you learned how to group shapes together. In advanced TinkerCAD, you will use the skills you have gained to create more complex shapes. TinkerCAD provides you with basic geometries such as cubes and cylinders. You can combine these shapes to create more complex geometries such as a house using the group function. To create even more complicated designs, you can combine shapes to be used to create complex holes

The example below will walk you through the making of a heart button. It will involve grouping shapes together in order to create a more complex shape and feature
[[File:Heart Button Construction.png|thumb|Combining simple shapes to create a heart shape.|alt=|left]]
# Add a box shape to the workspace. Make sure the dimension of the box has the thickness of the desired button. This will serve as the point of the heart.
# Add two cylinders with the same thickness as the box to two edges of the box. Set the diameter of the cylinder as the width of the box. This will create the humps of the heart.
# Using the round roof object, size it to the appropriate dimension for the button hoop.
# Copy and paste<s>r</s> a second round roof object and make it slightly smaller to be used to create the hole for the button hoop.
# Turn the object into a hole and position it accordingly.
# Finally, group the shapes together and the button is completed.

== [[Digital technologies/3D printing/3D modeling- Intermediate/Design for 3D Printing|Design for 3D Printing]] ==
There are some important things to note when modeling for 3D printing. It is important to optimize the print by decreasing print time and material while ensuring accuracy and strength of the part.

# Divide your model into smaller more manageable parts. There are many designs with complex details or large dimensions that would be more manageable prints if split into multiple parts
# Try to ensure that there is one flat surface on the print. This will allow easier print set-up. The flat side can adhere to the build plate, minimizing the need for additional build plate adhesion.
# Avoid floating parts. All aspect of the model should be connected to the main model. Minimize overhangs in the model as well. This will prevent wasted time and material to print supports.
# FDM printing has limited capabilities with dimensional accuracy. It is recommended to prevent printing horizontally oriented holes of the smaller size. These holes are often deformed and printed with difficult to remove supports.
# Printed parts are stronger in one direction than another. It is important to keep this in mind when designing. Prints will be weaker in the areas where the layers meet. This means that printed parts have low tensile strength along the Z-axis. The prints will be the strongest in planes parallel to the build surface.
# Exaggerate the details of your designs. This is an important thing to keep in mind. In order for details to show up on small designs, you should make your cuts deeper and bigger. It can also be helpful to make slender designs thicker.
# Exaggerate the details of your designs. This is an important thing to keep in mind. In order for details to show up on small designs, you should make your cuts deeper and bigger. It can also be helpful to make slender designs thicker.
#

If your design is to be used in (electro-)mechanical assemblies in which there are interfacing components, it is important that you understand three basic tolerancing concepts and to keep them in the back of your mind when modeling or more generally designing these assemblies.

# Form: The form of a part refers to the overall dimensions and the shape of the exterior surfaces of a component. Think of a flaw referring to form as a print that ended up not matching the base geometry that was used to create it in CAD due to adverse physical variables during the printing process. Examples follow:
## A ''sphere'' may end up slightly ''oval'' once printed due to improper cooling, etc.;
## A pillar might end up tilted to one side due to improper belt tension between the belt axes, etc.;
## A pin feature might end up too large to fit its mating hole due to the printer outputting too much material when producing the outer walls of the feature (the inverse can also be true).
# Position: Position refers to the distance separating a feature and an (ideally) meaningful reference (i.e.: the distance between a hole and the side of a part, or between two holes). Thankfully, flaws pertaining to position are rare on a properly tuned printer, as the printer does not have any information about existing references other than the build plate. If tuned properly, the printer will always print a feature at a position (X,Y,Z) distance relative to another feature, because that is what the gCode will tell it to do. You can imagine, however, that if the part is warped, the 'build plate reference' is no longer valid, and such, warped parts almost always have features out of position ''unless the meaningful reference (interfacing feature) used in the design is not the build plate''. However, since the build plate reference is such an important one to define the Z position of features (for the printer, that is), making your meaningful reference something other than the build plate does not always guarantee you good positional tolerance independent of warping.
# Surface: The surface finish of a part is a rather complex subject. In 3D printing, and for typical applications of 3D printed parts, it mostly refers to the mean (statistical) difference between the height of cusps and valleys on a part and their deviation from that mean, at a macroscopic level. The most important consideration is that when 3D printing, most surface finishes are quite rough (deviate significantly from the mean), and thus are sanded down considerably to knock out the cusps left by the printer. This post processing can negatively affect the form of the final part.

Note that ''a proper mechanical fit between components demands a good tolerance on form, feature position, and surface finish'', such that it is typically impossible to obtain a proper fit when 3D printing, and that if you are considering the 3D printing of critically interfacing components, 3D printing should not be used unless post processing ''is built into the design''. For mechanical designs, you will notice that a main application is brackets. This is because brackets only need good positional tolerance on holes and mating faces, which 3D printing can almost always provide (the tolerance on form for holes is not that important since they are typically clearance holes). However, since some brackets are easily laser cut, 3D printing brackets is only done under certain specific conditions. It certainly has shown its commercial use in cost cutting by replacing intricate multi-part assemblies by ''generatively designed'' (we'll say computer generated for now) parts, as shown in the picture below.
[[File:Design for 3D Printing Generatively Designed Bracket.jpg|center|thumb|600x600px|A metal 3D printed generatively designed bracket (computer generated from load data, using Finite Element Analysis), likely replacing a multitude of other parts that would have been manufactured using traditional manufacturing methods which would lead to a heavier and more expensive bracket.<ref>CarrusHome (2021). GM Explores 3D printing, generative design for next gen parts. Consulted on 05-05-2022 at <nowiki>https://www.carrushome.com/en/gm-explores-3d-printing-generative-design-for-next-gen-parts/</nowiki></ref>]]

==[[Digital technologies/3D printing/3D modeling- Intermediate/CAD Extensions|CAD File Formats]] ==
In the beginner section of 3D modeling, you were introduced to TinkerCAD. In the instructions, you were instructed to export your 3D designs as a STL or OBJ file. In this section, the differences between different CAD file formats will be discussed.

=== [https://en.wikipedia.org/wiki/STL_(file_format) Standard Triangle Language (*.STL)] ===
STL files are the most used file format in 3D printing and 3D modeling. Most 3D printers support the file format. Many of the 3D printable models online are also found in STL file format. STL stands for stereolithography, a 3D printing process created at 3D Systems in <ins>the </ins>1980s. STL file format encodes the surface geometry of a 3D object. This is done through tessellation, a process of tiling a surface with one or more geometric shapes so there are no overlaps or gaps. The basic method of tessellating the outer surface of 3D models is through the use of tiny triangles (called “facets”) and store information about the facets in a file. For example, in the figure below, it shows how a cube can be represented by 12 triangles while 17000+ triangles are needed to represent a sphere. Since triangles consist of three straight edges, it can be difficult to approximate curved geometries. To do so, mesh density is increased, and individual triangle’s size is decreased.

STL file format stores the information as the coordinates of the vertices and the components of the unit normal vector to the triangle. The normal vector point outwards of the 3D model.

There are a couple of rules for tessellation and storing information. The vertex rule states that each triangle must share two vertices with its neighbouring triangles.

The orientation rule states that the orientation of the facet must be specified in two ways. The direction of the normal should point outwards, and the vertices are listed in counter-clockwise when looking at the object from the outside.

The all-positive octant rule states that the coordinates of the triangle vertices must all be positive. This ensures that all coordinates stored would be in the positive which would save space in the file. Finally, the triangle sorting rule recommends that the triangles appear in ascending z-value order. This is a recommendation rather than a rule as it helps the software slice the models faster.

=== [https://en.wikipedia.org/wiki/Wavefront_.obj_file Wavefront OBJ (*.OBJ)] ===
OBJ is a crucial file format in 3D printing. It is generally preferred for multi-colour 3D printing. Often, it is used a s an interchange format for non-animated 3D models. OBJ file format stores information about 3D models by encoding the surface geometry of the model. It also stores information about its colour and texture. It does not store any data about animations or scene. It is open source and neutral. Therefore, it is often used to share 3D models since many CAD software supports the format.

It differs from STL since it stores colour and texture information. STL is an older file format that is missing modern features. It does not support multi colour printing or high resolution prints. OBJ can approximate surface geometry well without drastically increasing the file size. It also supports multiple colours and textures in the same model.

OBJ encodes surface geometry of a 3D object in many different methods: Tessellation with polygonal faces, freeform curves and freeform surfaces. Similar to STL, OBJ allows tessellation of the surfaces with simple geometric shapes like triangles or more complex polygon. This is the simplest way to describe surface geometry. However, approximating curved surfaces with polygons will introduce coarseness and geometric deviation from the model. The size of the polygons can be decreased to increase the quality of the prints. However, this can lead to giant file sizes which can be difficult for 3D printers to handle. It is important to find the right balance between print quality and file sizes.

The surface geometry can also be defined using freeform curves. The user defines a collection of free form curves that runs along the surface of the model. The surface is then approximated using the collection of curves. It is more complicated than polygonal faces, but it allows for fewer data to describe the same surface. The curved lines can be described using freeform curves with a few mathematical parameters. It allows for higher quality encoding without drastically increasing the file size.

=== DS Solidworks Parts (*.SLDPRT) and DS Solidworks Assemblies (*.SLDASM) ===
Sldprt file formats are native SolidWorks file extensions. It provides details on specific parts within a system. This is a software specific file format. Opening SolidWorks files in slicers and other software may cause some corruption of your designs. However, because it is software specific, it contains the most information about your models. As such, you should do all your modeling while the files are in native format

=== [https://en.wikipedia.org/wiki/ISO_10303 ISO10303 - Standard for the Exchange of Product model data (*.STP, *.STEP)] ===
STEP file format is a neutral file format. It is the most common file format used to share 3D designs. This allows users to open others’ designs using the software of their choice. It stores 3D images in an ASCII format. While STEP files can be opened with most CAD software. It is not easily edited. The model will display as a finalized object. Users cannot edit specific dimensions or features of the model.

===Polygonal Formats===

*[https://en.wikipedia.org/wiki/STL_(file_format) Standard Triangle Language (*.STL)]
*[https://en.wikipedia.org/wiki/Wavefront_.obj_file Wavefront OBJ (*.OBJ)]
*[https://en.wikipedia.org/wiki/3D_Manufacturing_Format 3D Manufacturing Format (*.3MF)]

===NURBS Formats===

====Standard====

*[https://en.wikipedia.org/wiki/ISO_10303 ISO10303 - Standard for the Exchange of Product model data (*.STP, *.STEP)]
*[https://en.wikipedia.org/wiki/AutoCAD_DXF AutoCAD Drawing Exchange Format (*.DXF/*.DWG)]
*[https://en.wikipedia.org/wiki/IGES Initial Graphics Exchange Specification (*.IGES)] (standard last updated 1996)

====Software-Specific====

*DS Solidworks Parts (*.SLDPRT)
*DS Solidworks Assemblies (*.SLDASM)
*DS CATIA V5 Parts (*.CGR/*.CATPart)
*DS CATIA V5 Assemblies (*.CGR/*.CATProduct)
*PTC Creo Parts (*.PRT)
*PTC Creo Assemblies (*.ASM)

*Fusion 360 (*.F3D)

It should be noted that Fusion360 stores files on the cloud, such that locally saved .f3d files are not commonly encountered. It should also be noted that OnShape does not have a file format given it is hosted entirely on the cloud.

==[[Digital technologies/3D printing/3D modeling- Intermediate/Using Parametric NURBS Software|Introduction to Fusion360]]==
TinkerCAD is known for its simplicity, meaning it is easy to learn and use. However, its capabilities are limited. It uses a drag and drop method to create basic geometries. Theses shapes can be grouped to create more complex geometries but it takes more time to design something complex and has less flexibility. Fusion<ins> </ins>360 is a sketch-based CAD modeling software that allows for users to completely customize their design. It allows users to design 3D objects using 2D sketches.

Fusion 360 offers 3D CAD modeling, PCB design, and 3D simulation capabilities. It is a fee-based subscription software, however, a free version is offered for personal use. The free version has some limited capabilities but most of the 3D CAD features are offered. Even with the limited features it offers more design options than TinkerCAD. To download the software, you can use your AutoCAD account and follow the link below: <nowiki>https://www.autodesk.ca/en/products/fusion-360/personal</nowiki>

Just like TinkerCAD, and with any CAD modeling software you choose to use<ins>,</ins><s>. Y</s><ins> y</ins>ou can export your part designs as an STL file. Using this file format, you can use any slicer of your choice to slice the design into a gcode file to print.

=== Fusion 360 User Interface ===
There are 5 main areas of the user interface. When the software is first launched, you should be seeing the screen above.

# Data Panel: On the left is the data panel. It displays pinned and recent projects, providing easy access to these projects for the users. It will also display sample projects that corresponds to the tutorials offered by AutoCAD. Users can also upload their projects to be shared with others for collaboration.
# Tool Bar: On the top of the screen sits the tool bar. Through this, you can use any of the features displayed to manipulate the 3D model you create. The shortcuts can be customized to display the ones you favour.
# Browser: Located at the top left of the main screen. It displays the model design with a file tree structure listing all the components, bodies and constructing plane. The files can be navigated through by clicking on their names. They can also be renamed by double clicking. The files can be collapsed using the triangles. The visibility of the bodies and planes can be toggled by clicking on the lightbulb.
# Timeline: The timeline of the design history is displayed at the bottom of the screen. This is a special feature of Fusion<ins> </ins>360 that is different from other CAD software. It keeps a record of the construction of the 3D model allowing the users to playback the building of the model. This feature also allow<ins>s</ins> users to add to the model from a previous state of the model.
# Navigation bar: The navigation bard allows users to change the view of the model. These features exist<s>s</s> as shortcuts when used with a mouse. For this reason, it is recommended to create CAD models using a physical mouse instead of a track pad. Some features include:
#* Zoom In/Out by scrolling up/down with the mouse.
#* Pan the model by holding down the wheel of the mouse.
#* Orbit the model by holding down control + wheel.

=== Sketching ===
The sketch function is the most important feature of a CAD program. It allows users to sketch 2D drawings as the base to create 3D objects.

To create a rectangle, first click on “Create Sketch” from the tool bar above. Select the desired sketch plane. In the example above, YZ plane was selected. This is the plane which the 2D sketch will be created. You’ll notice the tool bar above has transformed to display sketch functions. Select “2-Point Rectangle” from the tool bar. Click on the origin of the sketch plane and drag to create a desired rectangle. The sketch features are defined with reference to the origin to position it in space. It is why it is recommended to have one vertex of the sketch to be defined as the origin. After the rectangle is drawn, you can define the dimensions of the 2 sides of the rectangle. You can toggle between the dimensions by using the “Tab” key on your keyboard. Press enter to confirm the sketch.

Next, the line tool will be introduced. Drawing a line is the most simple and versatile function of sketch. It will allow you to create any shapes you will need. Select the “Line” option from the tool bar. Hover your mouse over the rectangle, the mouse will be drawn to the line and an ‘X’ will appear. This means that one end of the line will intersect with the rectangle. Move the mouse towards the middle of the line on the rectangle until a triangle icon shows up. This signifies the midpoint of the line. Click to create the start of the line segment. Drag the mouse to create the line and click again to create the end of the line. You can also manipulate the dimension of the line manually by entering the value.

To draw the line at an angle, drag the line out at an angle. At this point, there should be an angle dimension displayed. This value can be altered manually.

To create an arc, select “Create” -> “Arc” -> “Tangent Arc” from the tool bar. This will create an arc tangent to two other entities. Left click on the vertex of where you would like the arc to connect. Then click on the other vertex to connect. Alternative to create arcs include 3<ins>-</ins> point arcs where you select the two vertex and the middle point of the arc or center point arc when the arc is create<ins>d</ins> by finding the center of the arc.

In order for a 2D sketch to be converted to 3D model, the 2D profile has to be a closed shape. This means all the lines and entities have to form a closed loop. This will be indicated with a light-blue shading inside the sketch.

=== Extrusion ===
The simplest way to create a 3D model is by extruding a 2D sketch, which adds a third dimension to the 2D sketch. Select “Extrude” from the toolbar. Hover the mouse over the sketch, closed shapes that can be extruded will be highlighted when hovered on. To select multiple shapes, left click on both shapes. In the extrusion settings that pops up on the right, enter the value for the third dimension of the sketch, the width. Click “OK” to confirm the extrusion.

You can select a new surface from the extruded object to sketch on. To do so, select “Create Sketch” and select the surface you would like to sketch on as the plane. Afterwards continue to sketch like normal.

Extrusion can also be used to cut. Sketch on the surface of the shape the geometry you would like to cut. Select “Extrude” tool and select the shapes you would like to cut. To remove material, enter a negative value in the dimension window. This indicates the direction you would like the extrusion to occur. On the screen, it will display a red region to indicate material removal. Press enter to confirm the operation.

=== Mirror ===
The mirror tool is an extremely powerful tool that can save the user a lot of time in creating the 3D models. This is especially useful when creating symmetrical objects. It allows users to mirror solid or small features. It does require the user to define the plane to mirror the features. There are many ways to create the plane. One of which is to “Offset Plane”

Under the “Construct” drop-down menu from the toolbar, select “Offset Plane”. Select a surface to offset from. This surface should be parallel from the plane you would like to create. Now enter the dimension you would like to offset the plane from the surface. Press enter when completed.

After the plane has been created, you can now mirror the features. Select “Mirror” under the drop<ins>-</ins> down menu from “Create” from the toolbar. Under “Type” parameter, you can select bodies, faces, features, or components. After the type has been selected, click on “Select” by Object and then the features you would like to mirror, you can also click on the features from the design history timeline. Then click on “Select” by Mirror Plane and the plane you would to mirror from. Now a preview will be displayed<ins>,</ins> to confirm press enter.

=== Fillet ===
Filleting the edges is a feature that is offered in Fusion 360 and not TinkerCAD. It can easily elevate your models. It creates rounded surfaces by adding or removing from a solid model.

# Select “Fillet” under the modify menu from the tool bar.
# Click on the edges you would like to round out.
# Enter a radius value to round the edges out to.
# Click “OK” to finalize.

== References ==
<references />