simple stirling hot air engine made at home with simple tools ,2 cans a baloon welding rod steel angle grinder disc for flywheel ,steel wool for displacer and some electrical connectors ,fishing line Check out my cool time-lapse video of how to make your own http://www.youtube.com/watch?v=jJ3eq-91KYQ&feature=youtu.be The next level stirling engine with lights and fan blades http://www.youtube.com/watch?v=tQ5LWou5evY