Sterling Fan Build

[b.lindsey]

Finally over the last few weeks I have been able to spend some time making chips again and one of the back burner projects I have wanted to do is Jerry Howell's Mini Sterling Fan. Just though I would share a few photos of progress to date.

Here are the three displacer parts not yet assembled.

The power cylinder.

The gland for the displacer rod and power piston insert.

What will be the top of the stand once those 4 13 degree 5-40 holes are drilled and tapped (still pondering that setup).

The bottom side of the displacer cylinder.

The power cylinder again with the cold cap and bearing standards installed.

And finally all the parts so far shown on an 8 1/2 x 11 sheet for size reference.

The hot cap is nearly done and I hope to finish that and get a good start on the crankshaft today. If there is any interest I will post additional pictures as progress continues.

Regards,

Bill

 

[b.lindsey]

Just noticed after posting...the sixth picture should say "displacer" cylinder assembly rather than power cylinder.

Bill

 

[hitandmissman]

Of course there is interest. Please keep the build info and pictures coming. Great looking work.

 

[Divided He ad]

Well I'm watching and very interested Bill ;D
Nice neat parts you have there.... I always think it must be a bit interesting putting fins into square stock?!


Keep 'em coming



Ralph.

 

[carbide_burner]

Looking good! I'll definitely follow. My first project, a Laminar Flow, is nearing end, and I think my next project will be a Stirling fan. I'm looking for drawings - any suggestions?

 

[shred]

Nice work.

Btw, I skipped the angled holes and baseplate on mine: http://www.homemodelenginemachinist.com/index.php?topic=1146.0

Carbide, when looking a while ago I only found two sets of easily locatable Stirling fan plans-- Jerry Howell's (he has a couple sizes) and Senft's Moriya (published in Steam and Stirling book 1). Moriya has better step-by-step instructions if you like those.

Pretty much any Stirling motor (LTDs excepted) will run a fan instead of a flywheel, so you're not limited to those if you want to get creative.
The stirling plans in the downloads section is very similar to the Moriya core, though it has been somewhat Anglicized.

 

[Brass_Machine]

Bill

keep the pictures coming!

Eric

 

[wareagle]

It looks like you have one heck of a start there! Please take us along for the rest of the journey!

 

[JMI]

Very impressive and clean machining. It is what I strive for and sometimes get.

Questions about the power cylinder. The fins were done on a lathe with a "parting tool" type cutter? The material it is made from is ?

Thanks

Jim

 

[b.lindsey]

Thanks to all for the nice comments. As to the power cylinder it is made from round mild steel large enough to mill down the four flat edges which form the base leaving a slight radius on each corner. I just used some stock I had. the fin spaces were cut on the lathe with tailstock support. It just happes that the .040" fin space called for is the same as the cut off blade width on my Sherline lathe. All of that was done before parting off from the original round stock. One of my most used accessories is an eight sided adapter which allows the lathe chuck to be mounted to it and transferred to the mill vise to cut the flats and then transferred back to the lathe for cutting fins, parting off, boring, etc....all without ever having to re-chuck the work.

The fins on the displacer cylinder on the other hand were cut with an .040 slitting saw using the rotary table and mill.

Will try to post some pictures of the hot cap this evening. It was made similarly to the power cylinder (less the fins) but out of stainless. I was worried about the wall thickness while boring it out. It narrows down to .0125" at one point but it turned out well and seems plenty strong.

Bill

 

[b.lindsey]

Shred,

I gleaned several ideas from your previous build post so thanks for the link back to that, especially how you attached the blades to the fan hub. As for the base, I will probably stick with the original design but modifying the inner diameter of the base to be a close fit to the dummy doorknob from which the alcohol burner will be made. The 13 degree holes I will have to do on the bridgeport or either purchase a tilting table capable of holding the 4" rotary table at the same angle. Anyway...some things to ponder over the next few days.

Bill

 

[Brass_Machine]

O/T...

Hey Bill, you got a thread on the engine in your avatar?

Eric

 

[b.lindsey]

I just have the hot cap to add to the pictures tonight...unfortunately the day job gets in the way during the week. At any rate the stainless turned well even on the Sherline, it just took a lot of passes of about .005-.007 to reduce the diameter of the rod stock from 1.250 down to .700...pretty tough stuff!

With the hot cap done and the base squared off... time to bore out the inside

And the finished (almost) hot cap (still have the 4 mounting holes to drill.

Hopefully more to add tomorow night.

As to your question Eric, no there isn't a thread on the engine shown in the avitar, but i can post some pics if you wish or you can see a video of it running on the website or I can try to post the video here if that is easier. Even as I am working on the fan project I am also working on a half size version the that same engine just because I like 'em smaller...plays the devil on your eyesight though or is that just older age creeping up...lol.

Bill

 

[Powder keg]

Looking great!!!

Wes

 

[Brass_Machine]

...
As to your question Eric, no there isn't a thread on the engine shown in the avitar, but i can post some pics if you wish or you can see a video of it running on the website or I can try to post the video here if that is easier. Even as I am working on the fan project I am also working on a half size version the that same engine just because I like 'em smaller...plays the devil on your eyesight though or is that just older age creeping up...lol.

Bill

Absolutely... Please do a picture thread on the other engine. Please!

Eric

 

[b.lindsey]

Eric, I did post some pictures of the avitar engine in another thread in the photos and videos section. Should be lableled as OPV Engine. Hope to have more pics in this thread tonight.

Regards,
Bill

 

[b.lindsey]

Just a little progress in the last day or so. The fan blades are at least cut and edges smoothed but not finished or polished by any means.

Here is a picture of the sandwich...four brass blanks .015 thick and the paper template on top. This was after bandsawing the excess stock and sanding down to the template outline so they would be as identical as possible.

The after de-gluing, cleaning in lacquer thinner, and de-burring the sanded edges. Once the hub is made and the blades attached, the final diameter should be about 5".

 

[b.lindsey]

Made a little more progress over the weekend after losing several hours hunting for the fan blades (shown above) which I had inadvertantly thrown in the trash with some junk mail. Fortunately they were found !!!

Finished up the mounting holes in the power cylinder, hot cap, and displacer cylinder so now everything attaches as it should.

Then began work on the crankshaft and got that done other than the third crankdisk for the power piston.

Then I assembled all the main parts to get an idea of what it will all look like assembled. So far so good.

Next will be the fan blade hub, the remaining small parts (con rod bearings, links, etc.) and the base. Hopefully another weekend's work and it will be ready to try out.

 

[Powder keg]

That is turning out AWESOME!!!!!!

Wes

 

[JMI]

Made a little more progress over the weekend...

wlindiii,

Where did you get that chucking device shown it the photos? It looks very interesting.

Thanks

Jim

P.S. The engine looks great!