This inchworm drive can move your contraption forward and backwards in a compact form factor. The order of operations is:

1. Stick the rear Sticker
2. Toggle rear Gearshift direction to extend piston
3. Unstick the rear Sticker
4. Toggle rear Gearshift direction to retract piston
4. Stick the front Sticker
5. Reverse front Gearshift direction to extend piston
6. Reverse front Gearshift direction to retract piston
7. Unstick front Sticker

"Rear" and "Front" are relative to the direction you're moving. Here I've used Creative Motors but you can attach separate 16-sail Windmills to each Gearshift with a Speed Controller to move each head of the inchworm drive at 256 RPM.