3D Printed Double-Acting Air Engine

3D Printed Double-Acting Single-Cylinder Air Engine This project is a fully working, 3D printed, double-acting single-cylinder air engine inspired by classic Watt-era steam engine architecture. It is designed as a functional desk model that demonstrates real reciprocating engine motion, not just a static display piece. Compressed air drives the piston on both strokes, giving smoother and more continuous rotation than a single-acting layout. The result is a model that is both educational and satisfying to watch in operation, with clear visual movement through the cylinder, linkage, crank, and flywheel. I designed this build to be printable on standard hobby FDM printers, with parts arranged for straightforward assembly and tuning. If you enjoy mechanisms, thermodynamic history, model engineering, or kinetic prints, this engine is a great weekend project. How It Works (simple overview) 1) Air admission: Pressurized air is directed by the valve system to one side of the piston. That press