Model Hot Air engines

Maybe there's something amongst this lot: Have you considered a Stirling engine instead of a hot air one? I keep meaning to build a large flat solar powered one, to see if I can get better watts/£ than a solar panel. Mark K.

Interesting. What would you use it for? Never built one myself, so am interested in your idea. Regards GeoffH Norfolk - UK

Maybe generating electricity. I could make a decent size Stirling engine but I can't make a solar panel.
I haven't built a stirling engine yet but loads of more complicated stuff.
Maybe you already know the basics of Sterling engines but I will repeat them anyway:
A Sterling engine gets it's motion from a fixed enclosed quantity of expanding and contracting gas. A displacer shifts the gas (air) back and forth between a heating and a cooling chamber. The displacer cylinder does not have any seal (or even be cylindrical in shape), it is purely an object that takes up space at either the hot or cold end while the air is displaced to the other. The working cylinder is the one that takes advantage of the expansion/contraction of the gas (I suppose it could also be a liquid) and converts it to motion.
You can use anything to heat a Stirling engine. My idea is to make the chamber flat enough for roof mounting and use the cooling end for heating domestic water. If the water heating capability is included in the calculation, it should easily beat a photovoltaic panel for overall energy efficiency.
Plenty of links to various configurations of conventional Stirling engines on google.
Regards, Mark

Hello Mark, Thanks for the explanation. I'm only familiar with hot air engines, but the principal sounds the same or similar. Latest issue of EIM, May 2004, is featuring a beginners series on Strirling-Cycle engines. This should be interesting. Camden also do quite a few books on the subject. Regards GeoffH

Here's a few links for you:
(Fairly easy to make rotary one:) animation, same site: I think the above might be what you are looking for? It's so simple and uncritical you don't really need plans.
Other links with animations: This one should become available soon for gas central heating to simultaneously generate electricity: Regards, Mark K.

What is the title of "EIM"
Thanks, Daniel

Engineering in Miniature. A monthly English publication, rival to Model Engineer magazine. Web site Some say better, but I like both. GeoffH
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