I made this ringbom engine using JB weld(for the piston and displacer rod, sanded lightly for a loose fit), some clear epoxy, the top of a Hoody’s plastic peanut container, some brass tubing bought from hobbytown, a rear mounted propeller, a plastic racing wheel, 2 small bearings, some .020 music wire, 1/2 inch white styrofoam, a plastic screw, and some aluminum sheet to make this engine. The only tools I used were pliers, an cordless drill, a knife and tin snips. Update: Ok, I’m full of it, I forgot that I needed to use a drill press to get the holes in the 1/4″ aluminum straight, and a hacksaw to rough cut the aluminum sheeting. I recently changed out the displacer to a lighter one and the stroke is smaller, it runs a bit faster. With just a flywheel instead of the prop, it will run about 600-700rpms on boiling water and ice.