Flywheel Diameter (Both Flywheels): 2.5" / 64mm
Product Weight: 9 lbs. / 3.5Kg
Integral Arch Main Supports: Corrosion Resistant Surface Treated Steel
Power Cylinders and Pistons: SUJ2 Hardened Steel
Flywheel and Piston Vents: CNC Aluminum
Cylinder Ports: Brass
Heating Head: 304 Stainless Steel
Axle Joints: Sealed high-precision miniature ball bearings. No lubrication required.
Background & Concept
The Stirling engine is a high-efficiency heat engine invented by Reverend Robert Stirling of Scotland in 1816. Since its invention, there have been thousands of variations, all stemming from Stirling's original patent in the 1800's. The term hot air engine is a catch-all for any heat engine that uses the expansion and contraction of air under the influence of a temperature change to convert thermal energy into mechanical work. The engine is fired using the included denatured alcohol burner. Heat from the alcohol burner is applied to the end of an air-tight glass cylinder. The air in the cylinder is permanently sealed inside the engine. This fixed amount of air is heated and cooled, causing it to expand and contract, thus driving the piston. As the displacer moves up, the air in the cylinder moves down to the hot side, so the air pressure inside the cylinder increases, causing it to push up on the piston. Alternatively, as the displacer moves down, the air in the cylinder moves up to the cool side, causing the pressure inside the cylinder to decrease, and pulling the piston down. This process repeats over and over again, setting the wheel in motion.