stirling engine

[daz]

While waiting on some bits turning up for the lathe my mind has been jumbled up with what I should make on it. A while ago I came accross "eco fans" that are sat on top of a wood burning stove and used to blow hot air about. After a wee while I managed to find out that they are driven by a stirling engine.
My problem is I can't find any drawings on the interweb that would suit, has anyone got experience of this? If you do I would love any info you may have.
My second question, and possibly a more important one, is this a bit ambitious for a first alreal" project? I have turned and milled loads of stuff but nothing ever as complex as this, but am I biting off more than I can chew?
Cheers
Daz

[woodguy]

Ecofans are not powered by stirling engines but by a small electric motor using power generated by a thermocouple.

There are a number of stirling based fans and you should be able to turn up some by searching this and other forums.

One can be found in the book Steam and Stirling engines you can build - I think Vol 1 but it could be Vol 2.

[daz]

Thanks for the info woodguy, its not the first time I have been wrong and it sure won't be the last! I have seen some stirling powered stove fans and will have to go and find the links now. The thermocouple idea intrigues me though, I am an electrical engineer to trade and its easier for me to understand the electrickery side of things. Some more investigation required methinks!

Cheers
Daz

[woodguy]

If you take a look on Ebay, you can find sellers of replacement thermocouples and motors for ecofans.

[daz]

cheers for that, I will take a look.
Here is a look for what I was looking at http://gyroscope.com/d.asp?product=VULCANSTOVEFAN
I Incorrectly assumed that the Ecofan worked the same way, what is it we all say about assumption?

daz

[DMIOM]

Ecofans are not powered by stirling engines but by a small electric motor using power generated by a thermocouple........

I've never seen an "Ecofan" but if they're operated by an electric motor, I suspect its not powered by a thermocouple.   Thermocouples/thermopiles can source a small voltage, but I think its more likely that they use a Peltier effect module.

Dave

[woodguy]

That's exactly what they are.

http://www.ebay.ca/itm/CARFAMO-ECOFAN-REPLACEMENT-THERMOELECTRIC-TEG-MODULE-/280435145417?pt=LH_DefaultDomain_0&hash=item414b3cbac9

[Brass_Machine]

I have a few of those down in the shop from when my nephew was into keeping CPUs as cool as possible.

hmmmm....

Eric

[David Morrow]

Google "Moriya stirling fan ".  I built one although I did make a bunch of changes to non-critical parts of the plan. Scroll down here and you'll see mine :

http://www.ldrider.ca/cnc/cnc-index.htm

[daz]

Nice looking stirling fan you have there, some really neat projects on your other pages too, I'm only dreaming of those standards at present. I managed to get some plans for the Moriya and have started the build. I like the idea of the round displacer body, it could save me a lot of machining as I only have 2.5" round aluminium and I wasn't looking forward to machining it all square!
What diameter is it?

cheers
daz

[David Morrow]

Nice looking stirling fan you have there, some really neat projects on your other pages too, I'm only dreaming of those standards at present. I managed to get some plans for the Moriya and have started the build. I like the idea of the round displacer body, it could save me a lot of machining as I only have 2.5" round aluminium and I wasn't looking forward to machining it all square!
What diameter is it?

cheers
daz

Mine is 2 inches in diameter.

I don't know why the original build is square. Maybe that's what he had on hand and left it there for aesthetic reasons.