Algodoo

Something I threw together for the heck of it. The motor uses arms that extend/retract, so gravity can power it. There's also a draggable clutch force slider, because why not?

The motor needs a very slight push to start, and will run in either direction. It also produces almost no power, but that's beside the point. I'm not sure which way it runs best, but I think counter clockwise gives you a little more speed than clockwise.

Keyboard Controls:

1 - Clutch (Hold for functionality)
2 - Ratchet release (Hold for functionality)

Set to run @960Hz, but could probably run at 30 if you wanted. I just finally have the equipment to run at high frequencies, so I set it super high nowadays.
If you want to change the frequency, head to your Algodoo options, and click the Simulation tab. 60Hz is default, but 100-120 is more stable, with little drop in PC performance.