How To Make Your Own Model

Onshape is a rapidly improving cloud CAD program. A variety of things can be done, including sharing models, creating drawings, and making assemblies. In assemblies, you can get multiple models and put them together and even give each piece properties, such as gear relations and slider mates.

(Onshape can seem challenging at first, but once you get used to it, it's pretty simple!)

TinkerCAD is an easy to use CAD program that uses primitive shapes (spheres, cubes, etc.) to create desired figures and shapes.

BlocksCAD is a block-programmable website that creates figures and shapes. If you want to make a new version of a figure that you created, just change the desired variable and rerender the model to have the model become longer, skinnier, or even generate extra structures on it.