he added a rubber membrane and a clever valve system to create a diaphragm air engine. This GIF is worth 115 words A round rubber diaphragm with a hole in the center creates a seal with the piston ...

To fix this, he printed a larger diaphragm for the engine, so the lower air pressure had more to push against. This allowed the engine to run for a good while before the tank filled up.

A pneumatic motor (air motor), or compressed air engine, is a type of motor which does mechanical work by expanding compressed air. Pneumatic motors generally convert the compressed air energy to ...