Stirlingengineforum.com

Hello everyone ,

I have build quite some stirling engines , but only a few did work.
The problem always seems to be that somewhere it's not airtight.

A video of my best engine :Video
The main air leaks are at the displacer rod seal.
I've only had succes with a fishing line and a small hole trough a balloon or something.
Whenever I try to make to make it with a rod, the air leaks out too much.
And when I get it airtight, the friction is to great...

How does everyone get it so well air tight and reasonable friction at the same time?

Thanks

One way to get enough of a seal for the displacer rod; instead of just a hole, make a guide out of a bit of tube that is a close fit on the rod, make it about 1" / 25 mm long, if you have some machinery you can get a bit fancy, other wise hold it in place with a suitable adhesive. Ian S C

Hey,

I am with Ian on this, length is the savior here, although I think you can get away with shorter than 25 mm, maybe even half of that. I found that a bicycle spoke makes an ok rod, with the bonus of threads on one side to attach it to something. The nut that goes on the spoke, once you file/drill out the threads, makes an ok gland for the air tightness. If your mechanical part is precise enough, you can add teflon lining to it (extracted, you guessed, from a bicycle cable housing). I also read about folks making a gland from epoxy (just oil your rod so epoxy dont stick to it)

cheers!

tomostre, thanks for the inspiration. The bicycle cable housing might be just the thing for something I'm doing.
Bumpkin