Astromedia is a German company that makes cardboard kits of scientific instruments, and this LTD(Low Temperature Differential) Stirling engine. It will get up to 228 rpm on boiling water, and will also run on ice, or vegetables cooked in boiling water. This is one of the cheapest Stirling engines I can find on the market, costing 21.90 Euros, around AU$44. Keep in mind if you get one that the instructions are in German only! Luckily, my sister knows German very well, and I could supply English copies of the instructions, since she translated the instructions for my engine.
