Importing parts are pivotal in creating realistic designs that the team can implement properly!
FRC suppliers especially provide CAD files for parts
If you’re unable to find a CAD file try to look on open-source CAD repositories like: https://grabcad.com/ - be careful with these sites though. It’s possible you may find something similar but not exactly what you want
Example of a supplier providing CAD files
McMaster-Carr: Bolts - Click on your part and you should see a list of CAD file types use STEP
CAD files will usually be at the bottom of a product’s page
Import STEP file directly into an Onshape document
After you have your STEP file, importing parts in Onshape is easy!
Once you're in a part studio navigate to the bottom left of the screen:
Click the plus
Click import
This will open file explorer; choose the STEP file for your part - most likely in your downloads folder
That's how you import parts into a document directly, but what if you just want to import a part into an assembly and not modify it? That's where part libraries come in! You can import parts from other documents or from part library additions from the Onshape Store (for free!). Importing every part you need into a single document can slow down that document A LOT so there are many ways to more efficiently handle your assemblies.
But is there a way to easily get FRC specific parts? Why yes, yes there is. The MKCAD library! You can use it for free here: https://appstore.onshape.com/apps/Manufacturers%20Models/2ZT7X5D646R3LM3ZND7LGBTYRVM4SVH6CDDGM6I=/description and use it by heading to any document and importing parts to any assembly or part studio by first getting add-on from the link above. And then clicking the add-on on the right of the screen in any document.
The menu that pops up has a list for just about anything you'd need from VEX Robotics, REV Robotics, Andymark, thriftybot, and many more FRC specific vendors! The parts and assemblies are even configurable! See the videos below for more information how to use part libraries in other ways!