Boehm Stirling HB11 "Heissluftmaschine" Stirling Engine

A brief running video of my Boehm Stirling "Heissluftmaschine" stirling engine. This engine operates by an internal piston pushing cool air into a metal chamber being heated by a flame, then moving the heated air into an expansion chamber where it can push an external piston to do work. The heated air cools and contracts, and the internal piston pushes the cooled air back into the heating chamber again. It was invented in the 1800's and is still used in rural areas to power well-pumps, because it can run on any source of heat (gas, coal, wood, even focused sunlight) unlike an internal-combustion engine.