Hot Air Engine

[Bogstandard]

I have just uploaded a set of plans for a hot air engine into the downloads section.

These are used for teaching students in basic engineering.
They are in imperial with metric conversion.
You might need to convert the BA sizes to nearest American equivalent.
No fancy exotic materials required and the crankshaft is loctited together.

John

 

[shred]

Thanks.. one of those is on my list as well. I'd forgotten there was a downloads section until now

(for anybody looking, scroll down and look over on the left side menu bar)

 

[Bogstandard]

Made a right bugger of the upload, I included the first picture in my post, but forgot to reduce it. But the plans are all ok.
I got onto my friend who is the instructor at the college and who supplied me the plans, and he says that most times instead of bronze they use brass, it is cheaper for the college. He also said that the people building them are usually mechanically challenged (don't want to do it, but forced by the powers that be), so I don't think anyone on here should have much trouble with one.

John

 

[wareagle]

I don't think we can have too many plans! I am finding myself taking bits from one thing and incorporating it into something different. Kind of makes the hobby fun, and gives the pieces some personality.

Bog, thanks for putting that up here!

 

[Powder keg]

Thanks for the plans Bog:O) looks like fun.

Wes

 

[Brass_Machine]

Hey John,

You want me to convert that over to a PDF?

Eric

 

[Bogstandard]

It's ok Eric,
It should do as is.
I should have thought really and done it to PDF myself.

Thanks anyway

John

 

[Brass_Machine]

no problem.

Looking it over. Thanks for the plans! May have to try this one...

Eric

 

[shred]

I made it into a PDF just to keep the files all together (I do that with random plans quite a bit), so if needed, I can upload that file.
I did just a little cleanup on the images too.

I did have a couple questions though-- what do they usually do for a stand/support, and what size flywheel (if any) does it normally turn?

edit: I thought some of the bits looked familiar and sure enough, it's closely related to the engine in Senft's Moriya Stirling Fan, but with some changes here and there that make it easier to build. Anyway, if you have access to those plans (it's in "Steam and Stirling Engines You Can Build", among others), you can skip converting the BA's back and forth. That turns a 10" fan blade and has a stand off the bottom of the cylinder studs.

One more Q for the Stirling gurus-- If I reduce the volume (diameter) of the hot end and associated bits a tad, since I have scads of 1" steel, do I also have to reduce the volume of the power cylinder? Is there anything magic about the total volume or ratios thereof?

Roy

 

[Bogstandard]

Nice one Shred,
Looks like someone converted the fan engine into English rather than American for use in the college.
It might be a bit better if I learn to read, then I will be able to understand all these books you keep telling me about, rather than just looking at the pretty pictures.

John

 

[Powder keg]

I think if you reduce the volume of the hot end you ether need more heat or a smaller power piston, to keep your performance, which will drop anyway, because your are making a smaller engine. Make since?

Wes

 

[shred]

I think if you reduce the volume of the hot end you ether need more heat or a smaller power piston, to keep your performance, which will drop anyway, because your are making a smaller engine. Make since?

Wes

Yeah, I'm not expecting the same performance (there's a nifty half-size version of this fan I've seen pictures of that I'd like to build someday), just checking that there's not some magic ratio of hot side to cold side that needs to be allowed for.

 

[Mr.Myford]

Here is a video showing the Moriya fan in action:

[youtube=425,350]3W_6GFfkb4k[/youtube]

Can you upload the plans for the Moriya too, Shred? If they are not copyrighted.

 

[Powder keg]

Great Video! Thanks for sharing. Hey Shred, You going to make one of those half sized versions?

Wes

 

[shred]

Yeah, I like the idea of a half-size one.. or at least one that lets me use the stocks of 1" round I have. The minis look cooler to me too

The Moryia plans are copyrighted (at least the book that I have with them in it is, hopefully the one low-res scan above counts as 'fair use'), but the plans John posted in the downloads section are rather close, so building a fan off that shouldn't be a problem-- work up a stand off the bottom of the studs and a 10" dia fan blade off the crankshaft and you'll have something very similar to the video there.

Jerry Howell has mini- and full-size stirling fan plans available as well.

 

[Brass_Machine]

My wife saw a hot air fan on antiques roadshow the other day. She recorded it and was very excited to show me. Now she wants one of her own. project time!

Eric

 

[BobWarfield]

Got myself a Fresnel lens on eBay the other day. They're cheap. I think a fan makes sense when its hot. Yep, there's a lot of sun when it's hot. Mmmm, hmmmm.

Wonder what I'll do with that Fresnel lens?

Those Stirling fans sure are neat...

Hmmm...

;D

BW

 

[shred]

Fresnel lenses sure are fun. I've not applied one to a stirling though.

I work at a high-tech place that has stacks of PC heatsinks about-- the high-end ones are pretty complex-- copper blocks feeding into multiple-output heat pipes and all sorts of fun Al and Cu fin shapes. Someday I'd like to see how well something like that would work to cool a stirling cold-end-- heat-pipes are amazing things with very low thermal resistance and could be used to relocate the heat-source from the engine in a useful manner.

 

[Turk88]

When I try to download the file it is an unknown extension. A .rar...why can't I get this to work?

 

[Cedge]

Turk
RAR files are like zip files, but in a different file format. You can get a free decompression program at www.tucows.com . Look for "Winrar" and install it.

Steve