Category Archives: mechanical tinkering

The Stirling engine

the finished machine

As a gift I received in the winter of 2014 a kit for a model of a Stirling hot air machine. The design plans, as well as the largely prefabricated parts, come from Mr. Klaus Künneth, the operator of the website

To build and install only a little manual skill and a few gauges and tools are needed. (Stand drill, drill and tap, a grinding block with polishing wheels, at least a sliding calliper, a little clear coat and machine oil). On some parts holes of various diameters are to be made. For example, on the flywheel, the connecting rods. In the cylinder and head cover, the mounting holes are to drill and thread to cut.

drill the flywheel

After preparing all the items, everything is polished to a high gloss on the polishing machine. Then you can start with the assembly. All in all, one should take a few hours to have the model beautiful, meticulous and functional. From a few parts is then also quickly made a small spirit burner, which provides the necessary heat for operation under the working piston. Everything together is then mounted on the clear lacquer-sealed wooden base plate.

finished polished unit
The functioning of the Stirling engine is described by Mr. Künneth on his website as follows:
“The Stirling engine is also called a hot air engine and is a heat engine in which a closed working gas such as air (in this case) or helium is alternately heated and cooled from outside at two different areas (hot side and cold side) to generate mechanical energy. The Stirling engine works on the principle of a closed cycle and is an example of the energy conversion of a poorly usable form of energy (thermal energy) in the better usable form of energy of mechanical energy. The Stirling engine can be operated with any external source of heat (or cold) (solar, wood, gas, liquid fuels, in this model with spirit).”
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