# Miniature Sterling Engine



## John281 (Dec 11, 2020)

I just finished my first attempt at a Sterling engine.  Since I got into this hobby five years ago I've spent a lot of time making fixtures and tooling and upgrades to the machines but not many projects just for the fun of it.  When my family members all drew names for Christmas gifts this year I drew my son's name.  He's an engineer so I think he'll like this little desk ornament from ole dad's workshop.
  It's a type of Sterling engine called a "Ringbom" where there is no mechanical connection between the displacer and the crankshaft.  It's powered by a small alcohol flame.  The entire engine is particularly small and it's very sensitive to fit and friction.  In fact, the piston and displacer sleeve are machined from solid graphite to keep friction at the bare minimum.  Machining the graphite was an interesting task in itself.  Most of the lathe was wrapped in aluminum foil to keep the graphite dust contained.  The little engine didn't want to run initially and I was beginning to worry that I wouldn't figure it out in time but a little more polishing and checking for leaks and that did the trick.  I'm not exactly sure what the problem was but I don't care at this point.
  I think I'll make a little wood base for it just for added bling.  I hope he likes it.  I know I had a lot of fun making it.


  The description and plans for this engine came from a book called "Miniature Ringbom Engines" by James R. Senft, Moriya Press.


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## rock_breaker (Dec 11, 2020)

Impressive work!


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## Boswell (Dec 11, 2020)

I bet everyone hopes you will get their name next year.


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## hman (Dec 11, 2020)

Mighty pretty!  I guess that's what's called a "quarter scale" engine


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## francist (Dec 11, 2020)

Wow, great job! I’m still trying to get me head around just how “not big” that little engine is. Very nicely done 

-frank


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