I've seen some amazing papercraft mechanisms, but I've never dreamt that someone would build a functional (for certain values of "functional") steam-engine out of paper.
This paper steam engine is based on his cad drawing of a Riches and Watts nominal 2 ½ horsepower vertical A-frame double acting simple slide-valve steam engine circa 1870-75. The original engine was used to drive a water pump to irrigate the fields of Norfolk. If this model had a scale, it would be roughly 1:19. I had to double the size of the eccentric and strap in order to make it buildable. Everything else is close to scale, but changed in design and apprearance because, well, paper isn't iron.
Everything will work on this engine, the flywheel turns, there really is a slide valve in the valve chest, the piston works, the cranks and the connecting rods, eccentric and strap all work if built carefully. This is the first version available. I am hoping that if you download it and build it, you will give me feedback, and help me to inprove the buildability, and correct any errors in the model. The final model stands about 12 inches high. I hope you have as much fun building it as I had designing it.
(via Paper Forest)