Alpha stirling displacement.

[Ian S C]

I try to get the weight fairly even. I find a set of digital scales is handy, but the thing is to make the pistons (and most every thing), as light as possible.
Ian S C

[aragusta]

how about the thickness of Heylandt crown ... ?
I plan to create 1 mm the thickness of Heylandt crown... is that okay ?

[Ian S C]

I'd go for .5 mm or less, I think my one is .4 mm, but my tame TIGGER does not like welding that thin, hope he gets new specs before the next welding job.
Ian S C

[aragusta]

how can you make that extremely thin Ian S C... i have try to make it , but the result is fail such as the shape is not circle anymore because of the press on a lathe..
and how can you weld the thin walls... thin walls can be damaged when welding such as the thin walls is not flat again or bumpy...
thanks for your response Ian S C..

[aragusta]

and what is the purpose of making a thin wall Ian S C...?

[Aviator168]

Better thermal penetration, and at the same time reduce thermal conductivity to the rest of the system so you don't get a "thermal short".

[Ian S C]

The method of thinning a tube requires a mandrel, this is just a steel bar/or reasonably heavy tube that will fit tightly inside the piece that you want to thin. It's best that you start with a bit of metal that is larger in diameter than you need, and turn it to size, DON"T remove it from the lathe chuck, put a drop or two of Loctite or similar retaining compound on the mandrel, and push the tube onto it(write down the reading of the last cut on the mandrel), now turn the tube to the mandrel diameter minus the thickness you require. Now you'll need a bit of heat to get the tube off the mandrel, I'll leave you to work that one out, just don't burn yourself too much, but that way you could get to .005", but .015" would be as thin as you need go.
Ian S C

[aragusta]

how to close a perforated tube if there is a hollow tube side? , by means of welding?

[Ian S C]

Do you mean the end? My first ones were made from solid stainless bar, I bored the out to size, put them on mandrels, and turned the out side. Newer ones have been made from thin walled stainless tube wit the hot end TIG welded on, this goes for the displacer, and the displacer cylinder. The cold end of the displacer gets an aluminium plug held in with Loctite retaining compound.
Ian S C

[aragusta]

I had designed this one...please kindly open this link.... http://i57.tinypic.com/259uxdc.jpg ...
All dimensions are in millimeters.... any advice?