Could I make an air engine made out of balsa wood or foam?
Very cool engine and very commendable for you to want to build one! As for the building materials the balsa wood would be a better option. Though it is fragile, each piece of the engine you build will be one solid piece of wood material. This is important for the valve components that are exposed to suction from the vacuum. The foam might blow apart into pieces, especially if it is Styrofoam, since that is nothing more than individual pieces of foam glued together. Balsa wood will also have less elasticity and will be able to take more force than foam; i.e. the push rods for the flywheel. And in this engine since some pieces do slide and rub against each other, the wood will not ware down as fast as the foam will, plus the wood has a much lower coefficient of friction and will slide much more easily and allow your engine to work better. One thing you want to keep in mind is since you will be using a more fragile material you really don’t want to apply as much force (air flow in this ca
