# Project II, stirling done



## Pertsa (Jan 15, 2010)

Hello all!

My second model engine is done, except final polishing. 
I`m satisfied, it runs. Not well, but few minutes on boiling water. Smaller cylinter and piston is problem.
Cylinder is brass, and I have Teflon and aluminium piston, tested both. These have too much friction. 
But I`m searching better material, glass cylinder and graphite piston. It is just hard to find these , 
 I bought glass syringe, but it is not a round. 
And second weakest point is brass bars between hot and cold side, I think. These conduct heat too much.

Here is few pictures.


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## Deferr (Jan 15, 2010)

Very nice looking engine. You may try nylon washers between the brass spacers and the plates as well as between the screws and the plates.


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## Blogwitch (Jan 15, 2010)

Very nice indeed.

If you are using ball races in you main standard, if you haven't already done it, they should be cleaned out with spirits to remove all lubrication in there. Then either run with no lubricant or just a tiny amout of very, very thin oil.

That reduces the friction dramatically.

Sorry to mention it if you have already gone down that route.

Blogs


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## Pertsa (Jan 15, 2010)

Thanks to Deferr and Blogwitch. Nylon washers is good idea, I must try this. 
I use rc ballbearings on mainshaft, these are covered with metal shields, I can try remove these and
clean them. Very good notify!
What is proper angle of pistons timing? I set it by trying, displacer goes now about 90 degrees ahead.


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## hobby (Jan 15, 2010)

Very Nice work.

Nice craftsmanship overall...


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## peteski (Jan 15, 2010)

For a free sample of a very nice glass cylinder and a graphite piston go to Airpot website. I got a free sample which I am going to use on a Stirling Engine if I ever get time to do it. Their address is Airpot 35 Lois Street, Norwalk, Ct 06851. Great looking engine. 

Peteski


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## Deferr (Jan 16, 2010)

Pertsa  said:
			
		

> Thanks to Deferr and Blogwitch. Nylon washers is good idea, I must try this.
> I use rc ballbearings on mainshaft, these are covered with metal shields, I can try remove these and
> clean them. Very good notify!
> What is proper angle of pistons timing? I set it by trying, displacer goes now about 90 degrees ahead.




The standard setup for these sorts of engines is 90 degrees phase difference between the displacer and the power piston.


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## Orrin (Jan 17, 2010)

Wow! That is some beautiful craftsmanship. 

I believe you are correct; the metal between the warm and cold sides of the engine is providing a thermal short-circuit.

It also seems as though the displacer diameter could be greater. With a power piston of that size, the displacer should probably be 40 to 50-percent larger. 

Best regards, 

Orrin


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## Pertsa (Jan 17, 2010)

I cleaned bearings, and I found one problem, bad bearing. It makes terrible noise when runs dry.
I replace it another one, clean them carefully and put thin oil to these. It runs much faster and longer now.
I measured 10 and half minutes,with cup of boiling water. Aluminiumpiston is little problem, it makes vibrating noises.
Teflonpiston jams totally when warms. I ordered free sample from Airpot, and it`s bit smaller than current,
hope it comes. Thanks peteski and thanks for all!


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## kendo (Jan 17, 2010)

Hi Pertsa 
       Beautiful piece of craftman ship, love the flywheel was this done on a cnc.
       Great pictures too.
                       Ken


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