2. Computer Aided Design¶
This week we learned about Computer-Aided Design (CAD). We are supposed to experiment and try out two 2D software and two 3D software to gain experience in different programs in order to identify which one suits us best.
Cuttle¶
Cuttle.xyz is a simple and free-to-use web-based 2D vector graphic software that can be used to make .png, .svg, .pdf, and .dxf files. The .dxf file format is important to us since it is the one that will be used for laser cutting.
- Vector graphic software refers to software that is used to create imagery and graphics using vector commands. This means that the images are created using commands and mathematical statements. This results in scalable design that can have it’s size changed without a loss in quality. Vector files such as .svg and .xml can be easily converted to raster files.
- Raster files on the other hand are made of pixels, which are tiny squares. This means that the quality, size, and file size of an image are directly correlated to each other, this makes scaling these images result in losses in quality. Raster files such as .jpg and .png are difficult to convert to vector files.
- I will not be exploring Raster design software because my requirement of 2D CAD software in FabLab is mainly for sketching ideas and for 3D printing. Both of which are more appropriate for vector graphics.
The UI of Cuttle is simple. When you create a new project a blank canvas appears. You can drag objects from tab on the left onto this canvas to add them.
After adding an object, you can move, resize and rotate it around by clicking on it and dragging in certain places in the transform box that appears. Precise size changes can also be done by clicking on the object dimensions and typing in the desired value.
You can also edit the object by using the panel on the right. This allows you to change parameters such as location, size, fill, and other object specific parameters such as font and spacing.
The default units are in inches, to change them go to the Units & Settings tab on the left. You can also set the fractions to be in decimal here.
You can go back to the canvas by clicking on components.
Cuttle’s free version only allows for 5 projects for one user at the same time, a simple workaround is to simply use different components in one project, effectively giving infinite projects to work with.
Another limitation of the free version is only 10 exports per month, for this reason you must be mindful to export only finished designs that you are sure you want.
To learn about the software I followed this wonderful guide by our instructor Nour Suwaidan.
And in the end I made this keychain with my name on it:
You can download it as an svg file here
I also experimented and made other designs.
Captain America’s Shield:
The Avengers Logo:
Repeat Functions
A feature of this program are the repeats functions. They are used to basically copy objects in certain patterns. This is similar to other features present in many design softwares.
Boolean Union
This feature is used to basically combine several objects into one. This is important because the files made in Cuttle can be used for laser cutting, and having overlapping lines in this scenario can ruin the end result.
Before:
Using the feature:
After:
Convert to Path
To get even greater control when designing something, Cuttle has a function to convert something to a path. This means that you can add anchors and edit the individual vectors defining an object.
By right clicking on an object and converting to path:
Then when you double click on the object you can see the individual anchors and vectors defining it.
You can then edit the vectors, or double click to add another anchor to allow for more customization freedom:
Parameters
You can also set custom Parameters in Cuttle by pressing the plus sign either under the project name or component name, this will allow you to use a Parameter with a customizable value in the project or only in the component.
You can use this parameter in the transform tab for any object:
Fusion¶
Autodesk Fusion is a CAD software with CAM and PCB Design capabilities. It can also be used for 2D vector design because it can export sketches as .dxf files.
Normally Fusion costs money, but because I am a college student I was able to get 1 year free access of the education version. Alternatively, Fusion also has a limited but free edition available for non-commercial use.
To start using Fusion you have to create a sketch:
Then you have to select the plane you want to sketch on. After doing so, the sketch menu appears, from here you can select a tool you want to use and click on the workspace to start sketching.
For example, to create a rectangle I selected the 2-Point Rectangle tool, clicked on the point in the center to define the starting point, and then to finish drawing the rectangle I have to simply click again.
You can define dimension by using the sketch dimensions tool, alternatively, the cursor will automatically snap to the grid according to the level of zoom. You can stop the grid snapping for more precise control by going to the grid and snaps button on the bottom.
There are shortcuts to use the different tools, but I did not bother learning them because I felt that learning different shortcuts for every software would be too tedious.
Fusion also has a timeline on the bottom so you can see your changes, you can drag the line to basically go back and forth to see the effect of your changes, or you can right click on each action to edit or delete.
2D Design¶
You can continue in the sketch mode to create more complex vector graphics, and even export them as .dxf by right clicking on the sketch from the project file browser on the left:
Useful tools for vector graphic design in Fusion include geometrical constraints, these are important when you are trying to make a realistic or uniform shape.
I recommend the following video for anyone without a background in engineering or any who simply needs a refresher in how constraints work:
3D Design¶
Fusion can be used to make 3D solid models based on 2D sketches. To do so, the extrude tool is used:
After making a sketch and using the extrude tool, the 2D shape can be extended in one or two directions to make it 3D.
If the sketch does not get selected automatically or you want to select only certain areas to be extruded, you can define this desired area from the selected profiles by clicking on profiles in the left menu and clicking on the sketch area you want.
Using these features I made a simple model of my phone and a stand:
I used two bodies to make this model, so, to upload the design to Sketchfab as a single file, I simply used the combine tool to combine the two bodies into a new component:
Making the bodies a component allows us to export the model as a single file. We can do this by right clicking on the model from the browser on the left:
The .usdz format seems to be the best option that fusion can do in terms of file formats uploadable to Sketchfab.
SOLIDWORKS¶
As a Bahrain Polytechnic Mechanical Engineering student I have a lot of experience using SOLIDWORKS, I am even a Certified SOLIDWORKS Associate. But it is the only CAD software I have experience in so I am trying to use this opportunity to learn and try out different softwares.
For comparison I tried making the same phone stand from Fusion in SOLIDWORKS. It took approximately half the time.
Tinkercad¶
Tinkercad is a simple web-based 3D modelling software that is child friendly yet still allows for rapid prototyping of ideas.
To model in this software you only need to drag objects from the right panel onto the workspace.
Tinkercad also has a microcontroller circuit designer and simulator, I don’t have any experience with microcontrollers yet so I don’t know what I am doing with it. Hopefully, in the coming weeks I will learn more and be able to utilize this tool more effectively.