For my high school senior project, I decided to build a steam engine. With only a drill press, a dremel, and a hacksaw, I built a crankshaft connecting a 45 lb flywheel to two pistons. I hand-sanded piston heads out of HDPE so that they were airtight with the aluminum piping I used to make my cylinders, and created a valve system to connect and disconnect the pistons to steam out of commercially available plumbing products. The valves were actuated by a rod that connected to the crankshaft.