www.BuildSomethingUseful.com Here's my next engine. This is the first hot air engine I've made that produces electricity. It's not a lot of electricity but I gotta start somewhere right? This engine uses a computer hard drive for the flywheel so it is also a generator. I'm going to make another video with details on the individual parts if you are interested in making your own. I'm using an actuator I got from Airpot.com as the piston cylinder set. The piston is made of graphite and the cylinder is Pyrex which is basically glass.