Just finished building my second steam engine! Scaled up a little bit from the first one. 6061 aluminum for the stand, cylinder, crank, and connecting rod end. 1018 steel (1.25" diameter, 1.25" stroke) for the piston and flywheel, stainless steel connecting rod. Precision-ground 8mm steel crankshaft (1045?) Brass connecting rod pin and pivot bushing. Oak base 5"x5"x1", finished with olive oil.