Algodoo

To create this gears I wrote program which calculates position of all points and allows to paste it values to phun saved file.

This machine have 4-speed gearbox and allows you to move it with 4 different speed. Backward move is not avalible, but you can do some tricks with the internal gear to move it.

Controls:
W to toogle gear platform position (raised or lowered)
S to start/stop engine.
D and A to move internal gear from one drive gear to another.

For better control, recommend you to move internal gear only in raised drive gear platform position (analog of netural in car), in other case it can be some unpleasant effects.