The pneumatic grabber
Engineers (Advanced), mission M7 Fluid Power, lesson 1 of 6.
Hook
Push air in, the claw closes. No motor, no gears. How?
Fair test
Count pump strokes to close the claw. Test grip on 3 objects of different weight.
Bonus challenge
Pick up a ping-pong ball without crushing it.
The build
Pneumatic Grabber: A hand pump pushes air into a cylinder that closes two claw fingers. Let the air out to drop the load.