Ok, so I'm to lazy to weed through a search here!

[whitezin65]

Hi: I'm new to this site & have just discovered stirling engines. I've looked into purchasing several to sit on top of my wood stove to move the hot air around, but I don't have $175+! We heat with wood 6-7 months a year. Although I only have basic power tools (no welder or metal lathe), I'm pretty handy & an avid "tinkerer". I'd like to try to build a couple stirling engines wood stove fans. Can someone please direct me to a thread here or elsewhere that is a good DIY tutorial on how to make one that's sturdy, reliable, & actually moves a good bit of air around? Which design should I use? How do I figure out the size of the cylinders I'll need? What are the best repurposed materials to use?
I'm sure I'll have many more questions as I go LOL.
Thanks in advance, & have a great day!

[Tom Booth]

review
The Vulcan is the only commercially available stove top Stirling I know of. Some DIY plans are available for a "beer bottle" wood stove fan from James Eckert for a few dollars ($2,75 currently). The download page claims: "This Stirling engine has running on my wood stove every winter since 2010,", Though the plans actually state: "Warning: Never leave unattended engine on heat source!", which, I suppose is to avoid liability for whatever. It is just a beer bottle (glass) so could break if subject to excess heat I suppose. I have not had any experience with either of these stove top engines, but have downloaded the plans, which, IMO, look rather good. I'm sure this engine could be made more robust and reliable. The beer bottle displacer chamber for instance, is more for novelty than necessity.

https://youtu.be/2hi2SB3IciI

[Tom Booth]

This old circa 1913 apparently "free displacer" type engine might be adapted to run on a wood stove, to operate a fan, or whatever.:

http://builddoityourselfprojects.blogsp ... g.html?m=1

While also serving to add some humidity to the air.

Being water cooled, it might have less tendency to overheat than some engines running directly over the stove, at least until the water runs dry.

[whitezin65]

Thank you both for your replies! Greatly appreciated. How do I figure out the sizes of cylinder, chamber, piston sizes I need? For instance, I've found & cut a glass candle jar that is 5 inches across & 4 inches tall, & I've found a tin can that slides smoothly, but snugly inside of that for a displacement piston. But, how long should I make it, & what size should my power piston be? Is there a formula or ratio I should use?

[Tom Booth]

I don't know of any proven formula. There are so many possible variables.

Depending on your type and design, "snugly" might still be too tight for a displacer. Generally, air should be able to flow freely and easily around the displacer.

In most cases the power piston would be much smaller than the displacer.

A long time ago in this forum someone said that to determine such details they build the engine, apply the heat with the linkage to the piston detached from the crank and see by actual observation, how far the piston moves in the cylinder, by turning the engine, or moving the displacer, by hand, then make adjustments accordingly.

I think the throw of the piston should be adjusted so that the flywheel carries the piston slightly further than it would travel "naturally" by air expansion alone.

[Tom Booth]

This stove fan seems to be no longer available, but the diagram on this site might be of some use to help with a DIY project.

https://www.gyroscope.com/d.asp?product=THERMALENGINE

This image, apparently taken from the downloadable pdf manual, does not appear to bear any copyright. So, in case the page disappears:

Stove Fan diagram

stirlingfandiagram.gif (11.08 KiB) Viewed 3791 times

https://www.gyroscope.com/images/stirli ... sguide.pdf

[whitezin65]

Thanks for the help Tom Booth. Appreciate the diagram as well. I don't mean any offence, but I feel that this technology has been around for nearly 150 years, & someone who wants to build it for themselves shouldn't have to resort to trial & error to get it right. Maybe I should look elsewhere for the information I'm seeking. I work in the medical field. I have no schooling in engineering. But as I said in my original post, I'm good with my hands. I can also follow instructions & improvise pretty well.
Thanks again.

[Tom Booth]

Thanks for the help Tom Booth. Appreciate the diagram as well. I don't mean any offence, but I feel that this technology has been around for nearly 150 years, & someone who wants to build it for themselves shouldn't have to resort to trial & error to get it right. Maybe I should look elsewhere for the information I'm seeking. I work in the medical field. I have no schooling in engineering. But as I said in my original post, I'm good with my hands. I can also follow instructions & improvise pretty well.
Thanks again.

No offense taken. I generally agree as far as how it SHOULD be, however, I think the reality is that the Stirling engine is a technology that has largely been neglected and forgotten for the past 150 years.