The piston is made of graphite. The connecting rod is .026" music wire. The yoke is a #4 threaded rod (cutoff from a screw) affixed to the piston by two nylon nuts. The connecting rod attaches to a small (loose fit) hole in a flat-filed area of the threaded rod. The piston end of the connecting rod is bend to a square U shape. The bearing end is bent around a drill bit. The cylinder is aluminum with a polished brass tube insert held in place with CA. A short section of the cylinder is threaded to 32 tpi on a Frog for connection to the cylinder plate
. Alternatives: The cylinder can be made of solid brass or bronze and lapped.