The Stirling Engine Vortex

This is the external combustion Stirling engine that powers a marble machine. Made in Germany from machine-tooled aluminum and brass, the two-device apparatus is powered by a regenerative heat engine, put to its first practical use in 1818 by Robert Stirling. An alcohol burner in the engine’s rear heats a cylinder; a quick flip of its brass flywheel sets the engine’s displacement and working pistons into motion. The resulting expansion and contraction of heated and cooled air inside the piston operates a connecting rod which turns a second flywheel. This flywheel connects with a belt to the marble machine’s flywheel, which rotates to deposit eight marbles that each funnel down a brass spiral in sequence before each is reclaimed and deposited again. Non-toxic exhaust from a full burner of ethyl alcohol allows 15 minutes of operation. The apparatus and belt span requires a footprint of 15" W x 6" D.