The following is an easy to make Stirling engine that I built using a tomato paste can. It was made using the clear and simple instructions from Koichi Hirata's wonderful website.
Some tips in getting this Stirling engine to work.
A key point I found to get it working was to make sure there was a large enough temperature difference between the area of the balloon and the bottom of the can. I built and first tried it when it was relatively cool in my living room (air conditioner was on). It worked right away. I next played with it during the hot days during that north eastern North America 3-day power outage (no power, no air conditioner). It didn't work at all. There was not enough temperature difference between the area of the balloon and the bottom of the can. It also failed to work outside on a cool evening because the alcohol burner I'd put under it heated up more area than just the bottom of the can. So this is something to look for if it doesn't work right away.
Matching the heat energy input to the balloon and crank shaft
The air inside the can expands as it heats up and it's this expansion that pushes up on the balloon and the two connecting rods which then turns the crankshaft. But if the bends in the crankshaft require the balloon to inflate more than it can then it won't work.
As you can see below, I made three other crankshafts before I had one that worked. Each time I had to reduce the size of the bends so that the balloon wouldn't have to inflate as much.
Video of how to make a can stirling engine and how it works
Here's a video I made of it again a few years after the above original one. It includes an explanation of how it works and step-by-step demonstration of me making it.
Can Stirling engines made by others
The follow are can Stirling engines made by others using the the information from this webpage and/or video. If you've made one too and would like it shared here, contact me using the email address at the bottom of this page. I'd love to include it here!
JV Guglielmetti's can Stirling engine
Here's a candle-powered one by JV Guglielmetti () with just a length of wire for the flywheel. JV sent a video which I've seen and it works great.