Algodoo

So i was making a 2 gear garbox and i se a little movement
in "that circle", in a moment i think "What happens if i make that
gear bigger?" and this is the result

If you add spring constant you make circle get faster
If you quit spring constant the movement gets inverted
MAX=22 spring constant
MIN=0
Pros: Strange spring engine
fast and rare

Bads: "that circle" can runaway (it don't have special axle anti-runaway)