[doc1955]

Decided to build a Stirling Fan.
I also decided to make it a double build as I did with my last build.
The second one will again be a gift.











This is the first part the hot cap.
Here I start with a piece of stock long enough
For 2 parts plus enough to allow for parting tool.









Here are the 2 parts one end has been cut with the
End slots to help capture the heat during operation










I cut the slots using a hexagon collet block
Here I depart from the drawings this should be sufficient and easier to accomplish.










After finishing both ends I part into 2 pieces.











Here the 2 parts are split now load each and
Bring them to the proper length.










Face to length and rough drill inside diameter and finish bore.











Here I turned up a spud to slide part over the spud is a nice snug fit. I then turn down the under cut section of the hot cap. This section helps keep the heat at the end of the cylinder. I used the tail stock and a small scrap piece to pinch the material to turn.

[Deanofid]

These look nice, Doc. Is this one of Jerry Howell's projects?

You sure keeping in good with the family. Anyone would be thrilled to be on your "gift list"!

This should be another great build!

Dean

[doc1955]

Dean yes its Jerry's super Stirling I purchased the plans awhile back.

He's still showing all his friends the other engines I've built for him. He is fun to build things for. He gets so excited about them.

[doc1955]

Here are both part finished.




Next I worked on the displacer cylinder.


Picked out a scrap drop end piece of 7075 t6 aluminum.








Cut piece in half and layed out to rough mill out outside profile.






Rough milling part profile.





Pieces are cut to size.





Laid out the center and bore to aid centering in 4jaw on lathe.




Centering in lathe with dial indicator.






Parts have holes bored and ready to have cut cooling fins cut.


Next time turn up a mandrel to cut fins.

[Deanofid]

You're going at it, Doc. Double the parts count doesn't seem to slow you down much!

Dean

[SAM in LA]

Doc,

Looking good.

If I tried to make two engines at a time, I would scrap twice as many parts.

SAM

[Maryak]

Originally Posted by SAM in LA

Doc,

Looking good.

If I tried to make two engines at a time, I would scrap twice as many parts.

SAM

ME TOO

Best Regards
Bob

[doc1955]

Well got some time in the shop.
Turned up a mandrel to turn cooling fins everything went well during process.





Here is the mandrel noting special just fits snug slip fit to the bore in part and screw in end pinches it.



I used a part off blade with a full radius ground on the end and extended from holder just far enough to reach proper depth and clear the corners of the stock.














Here they are next the hole pattern for the hot cap and the power cylinder.


That will be next time.

[Deanofid]

Nice slim fins on these cylinders, Doc. Nicely spaced, too. That's something I always worry
about screwing up when I do fins.

Dean

[doc1955]

If you look closely you'll notice I did mess up the last fin isn't suppose to be there a .031 mistake. But the thing is it isn't the fins I messed up on but actually the base thickness. So after doing the fins on the first one I had to make the second the same. That's ok I'll adjust and it'll be ok.
What spooks me is the first few cuts with the part off blade keep picturing it grabbing the fin and ripping it off but honestly it has never happened (Knock on wood) but I have ruined a cylinder once when a parting tool grabbed and sucked in that happened in a 3 jaw. After that I take my time and make a mandrel and put it in a 5c collet.

Thanks for the comments Dean!