Some specialized components and things like bearings and sprockets are
available from the FIRST CAD library at www.firstcadlibrary.com
these are in many different formats for autocad and Autodesk Inventor.
These parts are specific to the FIRST robotics competition kit of parts
but include many common components as well. In particular, the DC
gearhead motors used in FIRST come from standard off the shelf
automobile components such as car window, seat, and van door motors.