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Discussion on Stirling or "hot air" engines (all types)
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srt
Posts: 5
Joined: Fri Sep 21, 2012 6:19 pm

New Member

Post by srt »

Hi I am a new member. I have built my first stirling engin but can not get it to run can someone help me?
vamoose
Posts: 267
Joined: Tue Jul 03, 2012 12:16 am
Location: Australia

Re: New Member

Post by vamoose »

srt,
describe your engine and also link a working/(non-working) video, or at least some pictures. There are plenty of good people on this forum that will assist you if they can.

vamoose
srt
Posts: 5
Joined: Fri Sep 21, 2012 6:19 pm

Re: New Member

Post by srt »

I have included photos of my engine. The displacer cylinder bore is 1.000 the displacer piston O.D. is .972 the cold cylinder bore is .812 cold cylinder piston O.D. is .810 engine stroke is 1.000. The engine has very little friction, if I spin the flywheel by hand without the regenerator tube on it will freewheel for a good 12 seconds be for it stops. I hope someone can help me see why it will not run.
Last edited by srt on Sun Sep 23, 2012 6:03 pm, edited 1 time in total.
Ian S C
Posts: 2218
Joined: Thu Dec 02, 2010 5:15 am
Location: New Zealand

Re: New Member

Post by Ian S C »

srt, I can't get your pictures here (try tomorrow on Broadband), but the first thing I spotted is the gap you have in the displacer, I don't think .014" is quite enough, .020" to .030" gap/ .040" to .060" on diameter would be better. With the narrow gap maybe you are not getting enough air passing the displacer, might feel OK when its cold. I'll have to see the motor. Ian S C
Ian S C
Posts: 2218
Joined: Thu Dec 02, 2010 5:15 am
Location: New Zealand

Re: New Member

Post by Ian S C »

srt, sorry can't get your picts here either, just the little box, with image, and a red X, the way I get in with my pics is by opening a gallery, then transfering from there, works for me, and does'nt cost anything. I'd like to see what you have, even if I can't help. Ian S C
srt
Posts: 5
Joined: Fri Sep 21, 2012 6:19 pm

Re: New Member

Post by srt »

I have included photos of my engine. The displacer cylinder bore is 1.000 the displacer piston O.D. is .972 the cold cylinder bore is .812 cold cylinder piston O.D. is .810 engine stroke is 1.000. The engine has very little friction, if I spin the flywheel by hand without the regenerator tube on it will freewheel for a good 12 seconds be for it stops. I hope someone can help me see why it will not run.
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Ian S C
Posts: 2218
Joined: Thu Dec 02, 2010 5:15 am
Location: New Zealand

Re: New Member

Post by Ian S C »

srt,Thanks for the pics, looks good, nice to see some machined work. How is the the displacer sealed around the connecting rod, there should be minimal leakage. Have you checked the displacer its self for leaks. I still think you have too little gap for the displacer. How long is the displacer? It should be about 3" long, a little + or - won't hurt. I hav'nt worked it out, but the swept volumes ratio should be 1 for the power cylinder, to 1.5 for the displacer. I'v got a BETA type motor with a crankcase, and found that I have to have an air intake to balance things out, with it closed the air was being compressed in the crankcase.
What is the piston made of? How good is its fit in the bore, and what is the cylinder made of? Nuff for now, I might seem a bit picky, but we'v got to get that motor going.
Hot air/ Stirling Engines are not rocket science, that stuff is far too simple, no its usually, if it does not go first time, it might be hours, or days, and a sore wrist flicking it over. Ian S C
srt
Posts: 5
Joined: Fri Sep 21, 2012 6:19 pm

Re: New Member

Post by srt »

Thanks guys for info and suggestions, I need to do some more calculations and modifications. It may take me 2 or 3 weeks since I just do this in my spear time, which is very little. I will be back with results and more pictures when I am finished Thanks again.
Ian S C
Posts: 2218
Joined: Thu Dec 02, 2010 5:15 am
Location: New Zealand

Re: New Member

Post by Ian S C »

Thank you for asking, best of luck. Ian S C
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