Longboy's STIRLING "Fantail" engine.
Longboy's STIRLING "Fantail" engine.
A Ross yoke drive with a horizontal diaphragm power piston. The power piston works without a guide supporting the connecting rod as it pushes the balloon in and out of the cylinder due to the Ross yoke imparting a very small angle to the con rod in reciprecation and the tension of the balloon self centering support on its end of con rod. The balloon was not ideal shape for the cylinder and its max diameter is more than the .625in. Pyrex cylinder used so there is more friction present. Adjustable con rod length connectors where attached to the Ross yoke to find the sweet spot for running. Lubricating the rubber with talc powder helps but is messy and short lasting. [youtube]http://www.youtube.com/watch?v=twyKNMj8bEQ[/youtube]