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?Chinese? Stirling Beam Engine

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klank:
My first post here - so hello to everyone.
I am very much a newbie to model engineering but have been "having a go at it" for the last 18 months.
I was retired early due to a back injury (Health and Safety rules) and decided to fulfill a boyhood dream of making something in metal and so bought my first lathe - never having had the opportunity to touch one before.
I have made a lot of mistakes but learned a great deal from reading what is posted on this site and others.

Anyway, I recently up-graded my lathe from a small Chester 7" (not a mini-lathe) to a larger Sieg C4 from a nearby machine tool supplier.
As part of the "deal" for the lathe, a "kit" of a Stirling engine was thrown in as a freebie. I have seen this kit advertised on Amazon and a couple of other places in the U.S., but never over here apart from the place I got the lathe from (not sure if you are allowed to "name names" on here).

Well, the comments on the Amazon site for this "kit" were not encouraging.
This is a "kit of materials" with detailed plans and some ?instructions? There is povided an Aluminium displacer piston and steel cylinder, plus a finished brass power piston. Everything else is Ally/Brass bar or hex stock, plus a length of stainless steel rod for the built up crankshaft.
To be fair, the materials are of good quality - each item individually labelled. The plans (one plan for each individual part) are excellent - over detailed in fact - showing tolerances etc.
The "instructions" are minimal in content and look as though they were translated from Chinese to Greek to Finnish and then to English. No instructions as to fitting, use of thread lock/silver solder or building up the crank and its main bearings.
Leaving their syntax aside, errors make them difficult to follow for a newbie - i.e. on one page it says the rotation from the "flying wheel" is clockwise, and on another it says it is anti clockwise. Go figure!

Anyhow, I finished it finally and after a lot of fettling/adjusting, got it to run freely.

Here is a pic. of the completed model - rigged up to a small ex. cassette recorder motor for "running in" purposes.




Has anyone else either seen this model or had any success in getting it to run?
Equally, if anybody has the kit and is struggling, I would be happy to pass on my trials and mods. in finishing it.

As at present, it does not run under heat - so trying a protracted "run-in" to see if it improves matters.

Just to add - I am amazed at the friendly nature that business is conducted here - I have gained so much from reading the posts. What a great site.

Best wishes to all

Peter

Brass_Machine:
Hi Peter,

Welcome to the collective!   :borg: Glad you like it here.

That kit had me scratching my head as to where I had seen it before. I just figured it out:



That is the same kit that Little Machine Shop Offers. As I have never built a Stirling (yet!), I don't have much advice. What I do know is there should be as little friction as possible.

One of the others may chime up with some more info.

Eric

bogstandard:
Welcome Peter,

So you have been going it alone, made a few mistake I suppose, and even then you still want to do more.

That is a sure sign of a wannabe model engineer.

Welcome to the bad back club, there are a few of us on here, but not of the type who can't get off it.

Even though this site looks like it is model engineering orientated, in fact it is for anyone who has some sort of project they either want to do, are doing, or just finding out about, so if you want to have a say in anything, just butt in. So really, as long as it is legal, we will discuss it.



--- Quote ---I am amazed at the friendly nature that business is conducted here
--- End quote ---

We really do want it to stay that way, so we just go about business as though we were down the pub with our mates, discussing things, with a bit of joking and leg pulling as well. But do be aware, sometimes serious stuff must be discussed as well.

Just pull up a seat and bide awhile.


Bogs

NickG:
I think a few companies seem to be stocking these models now. I know axminster and arc euro trade do them too.

I struggled for a while with my stirling. As well as the friction, ensure there are no leaks around the hot cap and the displacer rod gland.

If you get the friction down and the leaks down it'll work. It's achieving that that's the hard bit.

When I was having the problems with mine I spoke to many people including Jan Ridders, who nailed the problem down.

I think you can do the same thing on yours, or at least whittle potential issues down by the process of elimination.

Take your cylinder / hotcap / displacer / rod assembly off the rest of the engine, submerge it in a sink of water just with the power cylinder sticking out. Blow into the power cylinder. If there are any excessive bubbles around anywhere you need to seal these. There will be some around the displacer rod, unless you have a superb seal, in which case I could argue that it may be TOO tight. Bubbles from anywhere else are unacceptable!

The next thing to do is build the engine back together but take off the displacer cylinder to relieve any back pressure. With a flick of the flywheel it should rotate for at least 10 revolutions before coming to a stop. If it doesn't, something is too tight. Systematically take linkages off until you find the main contributer to friction, or start with just the flywheel in it's main bearings and gradually build up to the whole assembly.

Finally, make sure your displacement piston doesn't foul anywhere in the displacement cylinder or hot cap.

Another thing that improved the performance of mine dramatically was the wick believe it or not! I was using nylon shoe lace (couldn't find anything else) but then I changed to proper cotton wick and it ran at about 3 x the speed! Use some light oil such as sewing machine oil or 3 in 1.

Hope this helps, you will get it running, just persevere. The good thing about yours is that you know it's a tried and tested design so it will work if you can do the above. I was venturing into the unknown slightly with mine but got it working with a bit of theory and the above!

Nick

sbwhart:
Welcome aboard Peter.  :wave:

Stirling engines are something I've shyed away from I'll have to have a go at one someday thare I go getting  :proj:

You'd better watch out as its catching

Have Fun

Stew

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