Algodoo

Uses right and left arrow keys. Differential Winch using chain in place of wire rope. In real life wire rope works better. Good for developing high force or large speed reduction with just a few sprockets (or pulleys). I like Phun. The "No Phun" symbol is to prevent Phun users from expecting this to work OK in Phun. This scene is an oversimplification and the chain gets slack at the ends of travel.