Why? Well for one it is a great way to visualize and present your ideas, especially if sketching isn’t your strongest skill. It also provides a sort of guide for when you actually start building. If you just build it with no model, sometimes you discover things you had overlooked, and so you have to take it all apart and try something else. But if you CAD your robots first, you discover such things before you’ve started building, and don’t need to take anything apart. You can also use CAD software to almost create a set of instructions for yourself. you can build everything exactly as the CAD model shows and you know it will work. Plus I find it enjoyable. Its like building a robot, but without actually building a robot! Its also great for engineering notebooks, judges love those CAD blueprints.
Examples of what you can do with CAD
I want to make a drivetrain, but it seems like every time I do I overlook something with the wheel spacing or motor placement and it messes up my entire plan. So I’ll CAD one in advance!
Now I have an exact model of my drive! I did it all with free software and no physical parts, and now I know I’ll be able to assemble it all according to plan once I start building.
(this isn’t actually my drive, I made this a while ago.)
And lots of highly competitive teams use CAD as part of their design process.
Take 240P for example
I highly recommend all teams that have access and time to CAD do, it ends up saving time and energy later on, and is a marvelous tool we have easy access to.
I use Autodesk Inventor, which is free for all students and competitors, and has a ton of updated part libraries for easy assembly. But there are other options as well, Solidworks, and Fusion are other common CAD programs.