A cool Science Fair project Plans page now FREE: http://comptune.com/tincan.php (Your donations will go to needy children, however.)
These plans offer more than just the design and diagrams. They explain the technique I use for making many small projects out of recycled metal cans.
Stirling engines are easy to build. These plans can be put together in just a few hours using simple hand tools. It took me a lot longer to write the plans and draw all the sketches than it did to build it. As a kid, I once thought "Sterling" was the correct spelling but I later learned that these engines are named after Robert Sterling, a clever clergyman in the 1800"e;s, who added a "regenerator" to a regular heat engine to improve efficiency. Today, with modern materials, Stirling engines are getting another look because of their ability to use any heat / cold source for power! I have run a model like this one on liquid nitrogen as well as ice.