3 foot LTD Stirling Engine

Discussion on Stirling or "hot air" engines (all types)
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Just Ron
Posts: 5
Joined: Mon Nov 28, 2011 9:08 am

3 foot LTD Stirling Engine

Post by Just Ron »

Seen this 3 foot or so engine, and looks like two lawnmower heads for cooling fins, on youtube and I sent the poster of the video a email to see if he know who built it, so far no response. The video is a little strange but the engine is great. Does anyone know who built it? The video say's 2009, Portland Show.
Here is the link: http://www.youtube.com/watch?v=6g0FHZzP ... re=related
Thank you for any help. Would like to see him join and see what else he has.
Just Ron.
Ian S C
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Joined: Thu Dec 02, 2010 5:15 am
Location: New Zealand

Re: 3 foot LTD Stirling Engine

Post by Ian S C »

Might be a project in that, I'd say nearer to 4ft dia. I'll have to look around and see whats available, think the top and bottom plates may slow me down. Neat vidio, I have people looking at my engines at shows just like that, until I explain the workings. Ian S C
Doogle
Posts: 22
Joined: Tue Apr 05, 2011 2:18 am
Location: London, England

Re: 3 foot LTD Stirling Engine

Post by Doogle »

That is a nice LTD engine. I hope you can find the builder of the engine and perhaps he can give us the plans. Is it too low an output to do useful work?
Ian S C
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Joined: Thu Dec 02, 2010 5:15 am
Location: New Zealand

Re: 3 foot LTD Stirling Engine

Post by Ian S C »

There's enough info in the vidio to construct some thing similar. I'm quite sure that it uses diaphrams instead of pistons, so virtually no friction there. The only things I'd have difficulty finding are the top and bottom plates, and deciding what too use. Ian S C
Doogle
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Joined: Tue Apr 05, 2011 2:18 am
Location: London, England

Re: 3 foot LTD Stirling Engine

Post by Doogle »

Hi Ian, Yes I have been looking at it and agree regarding the piston. What do you think the displacer is made of? The design is as a model LTD engine. Rather than being an attractive curiosity (as the youtube video maker wonders what it is) I would like to think of an application for it. I have long wanted to scale up an LTD engine but have been concerned whether the output would be effective for any usage.

It certainly is a great display piece and inspires me to make one.
Doogle
Posts: 22
Joined: Tue Apr 05, 2011 2:18 am
Location: London, England

Re: 3 foot LTD Stirling Engine

Post by Doogle »

The annoying thing is there is a sign right next to the engine. I wish he had included that in the video.
Just Ron
Posts: 5
Joined: Mon Nov 28, 2011 9:08 am

Re: 3 foot LTD Stirling Engine

Post by Just Ron »

I have found another video of the LTD Stirling Engine, it is 4 feet. and this one did video the sign but does not really help. I have sent the person a email to see if he might have any information on who might have built it. Here is the link for the other video. http://www.youtube.com/watch?v=6UF_jHMDdKM This one was at 2009 Greenville Farm Power of the Past show in Greenville, OH. Now I am not sure but it looks like pistons to me, not diaphragms, I could be wrong, am most of the time. :mrgreen: . Will post if I here anything.
Just Ron
jimlarsen
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Joined: Sat Apr 17, 2010 11:04 am

Re: 3 foot LTD Stirling Engine

Post by jimlarsen »

I think the displacer might be made of Owens-Corning pink closed cell insulation foam sheets. It also looks as if there is air space sealed in plexiglas over the top plate to act as a solar collector and raise the temperature of the top plate. That's not a bad idea.
Ian S C
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Joined: Thu Dec 02, 2010 5:15 am
Location: New Zealand

Re: 3 foot LTD Stirling Engine

Post by Ian S C »

Just Ron, your right, they look as though they are graphite. I'v got one cylinder, it came from a damaged Chinese compressor. I agree that the displacer appears to be of some sort of foam. Ian S C
Just Ron
Posts: 5
Joined: Mon Nov 28, 2011 9:08 am

Re: 3 foot LTD Stirling Engine

Post by Just Ron »

A little more information on the 4 foot engine. I did find the nephew of the builder and he had a little information and he said that I could post his reply: "I took the time to look things up on the forum and can answer a few questions. The displacer is made of foam insulation. There are two small guide rods inside the displacer chamber to control how much it flexes as the foam isn't very rigid. The top and bottom plates are made of aluminum sheet. Unfortunately I don't know what gauge. The power pistons were turned out of graphite. The cylinders were cut off of an 18hp Briggs & Stratton opposed twin engine. My uncle also built one with a 2 foot diameter displacer a few years prior to building this one. I don't think the power output is significant enough to do anything meaningful. He built it mostly as a challenge to those who said it wasn't possible to scale a LTD engine up to that proportion."
Hope that if any one can or does build takes a lot of pictures and may be get Jim Larsen to put the plans in his next book. LOL :razz:
Just Ron
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