Author Topic: coffee cup stirling  (Read 1716 times)

Offline chucketn

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coffee cup stirling
« on: November 19, 2014, 08:39:42 PM »
I'm building the coffee cup stirling from www.scraptopower.com. The plan doesn't mention how much movement is needed in the displacer, just that less is better. I've got the displacer made and it has about 1/4" movement. Will that be enough?

Chuck

Offline b.lindsey

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Re: coffee cup stirling
« Reply #1 on: November 19, 2014, 08:43:38 PM »
Chuck, I am seeing a lot of links on that site but didn't see a reference to Coffee Cup Stirling by name. Maybe I missed it...is there a link that will go directly to the engine you are building?

Bill

Offline chucketn

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Re: coffee cup stirling
« Reply #2 on: November 19, 2014, 08:44:58 PM »
Sorry, Bill. I'll fix that in a moment.

Chuck

Offline chucketn

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Re: coffee cup stirling
« Reply #3 on: November 19, 2014, 08:54:28 PM »
A picture is here:

http://www.scraptopower.co.uk/pdf-downloads

Bottom most picture lableled Coffee cup LTD Stirling engine plans. I downloaded the plans and am working from them. I used the bottom s of 2 pull top vegtable cans and a strip of clear plastic to make the displacer. I epoxied a piece of 1/8" brass tube in the top of the displacer, a coke bottle cap  and baloon for the power cylinder.
I'll post pictures after my camera warms up, I left it out in my unheated garage for several days...

Chuck

Offline b.lindsey

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Re: coffee cup stirling
« Reply #4 on: November 19, 2014, 09:40:28 PM »
That helps a lot. It looks like he is shooting for 8mm total displacer movement, or an offset of 4mm in the crank X 2. Your 1/4" would be a little shy of that but may still be enough. 8mm would be right at 5/16". Looking forward to seeing more when your camera warms up :)

Bill