Air Powered Steam Engine

thingiverse

Working model of a steam engine powered by compressed air. Tolerances between pistons and engine housing are tight but will loosen with use, possibly requiring a gasket between top and bottom blocks depending on flatness and tolerances. M5 bolts, nuts, and washers are required for all connections; locknuts are suggested for linkage arms. This is an excellent teaching aid to demonstrate steam engine components and mechanisms, converting linear motion into rotary motion. It's a basic model of the James Watt engine. Students and teachers can learn more at study.com/academy/lesson/james-watts-steam-engine-facts-lesson-for-kids.html, www.bbc.com/teach/class-clips-video/the-invention-of-the-steam-engine/zkvygwx, and medium.com/@badeekhoury/the-father-of-all-engines-the-steam-engine-9f53053e870. Assembly notes recommend using a strong filament like ABS or Nylon for a working model, but PLA will also work. Use minimal air pressure to create movement – less than 10PSI is sufficient. It's better to hand-start the movement than to use too much air pressure. The shafts of the Drive Piston and Valve Piston are intentionally larger than corresponding inlet holes in the engine body, shaped as polygons instead of tubes. This allows for sanding to match printer tolerances. A tight but moveable fit is necessary to avoid undesired pressure loss, requiring manual tuning. Dry lubricant is recommended on shafts and internal moving components. The engine body may need elevation on a small platform to create horizontal alignment with the crank assembly. In theory, double-jointed shaft assemblies allow for height variance like actual steel/iron engine components, but plastics may not provide metal's rigidity. Raising the engine block minimizes undesired torque on shaft assemblies and improves performance. Additional assembly notes regarding the valve shaft are included in pictures.