This won't help you any but wanted to share.
I take a Catia (drafting program for DaimlerChrysler and others). So this semester I am in a Kinematics class (things in motion).
We get to model parts in 2D and 3D. Monday night we modeled (3d stuff) a machinest vise, a helicoptor rotor, shaft and drive gear. Some 2D stuff was a convertible top, metrodome, arbor press, plane landing gear(10 joints) and all these other 2D items.
it's pretty kewl as you select your different joints, you can place stops so it only goes so far. Then you pick a driving joint
put in your parameters and hit go and it will go through the motion.
gonna go back to lurking now
Pieter