Engine 2 was my first operating engine. I designed it to be simple and built it just with hand tools and a drill press. It doesn’t have a lot of power, but it can run from sunlight without mirrors or concentrating lenses. Typical operation is 60-150 RPM. Scale is difficult to tell in this photo. The displacer cylinder on top is a one-quart paint can. The flywheel is 5 inches in diameter.