This is a compressed air motor I built from stock. It was fun and frustrating machining the parts. As usual, being an online only student and not having access to any workshops (like the shop at AAU) I was required to purchase a lathe and mill along with a host of other items.

 

Below are images taken along the way from machining the parts to the completed motor. At the end is a video of the motor running on compressed air ranging from 20psi to 40psi.