by thedoctor, published
A 3D printable piston. This is my entry for the Makerbot giveaway. This is a single acting piston, air is forced in under the piston rod, which lifts it up. You then let the air out to make it go down. There is no top to the cylinder.
The piston must be printed in two parts, the cylinder and the piston rod, so you will need to move each part onto a separate document. once each part has been printed, you should use a file and a pair of calipers to adjust the cylinder so the piston rod has a tight fit.