Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines

I've often thought of trying to build one, and have decided that if I ever do, I shall make the pistons be essentially spheres. The reason being that to correctly make one of these elbow engines, the alignment of the 90 degree bend with two sets of cylinder bores must be essentially perfect or binding will result. Spherical pistons, while clearly providing a lessor seal, and thus less efficiency, will at least allow operation without requiring quite the same level of perfection.

Guess, I'm just thinking to take the cowards way out when it comes to precision machining.   ;c)