Small DIY Stirling engine drives 19" fan, 350 rpm!

[DUSTINM97]

i want to make a stirling engine sobad!

[BENJBIDA]

Can that be an electric fan?

[approtechie]

@BENJBIDA I'm sorry but I don't understand your question. The fan blade is from an electric box fan but it's being driven by my engine since it's connected directly to the crankshaft. The whole idea here is that you don't need electricity to have a functioning fan or whatever, you just need a heat source.

[virtualnoodles]

i really hope you reply to this. I'm wondering if you can run the hose from the bucket to a radiator in front of the fan and make an air-conditioning. also if its not possible to have a chimney or just inconvenient you could have a pipe go any direction you want and just hook up a sterling engine to run a fan(though that may not work just an idea).

[approtechie]

@virtualnoodles You certainly could run the hose to a radiator and us the fan for cooling the water/heating the air. A chimney would help to get the heat away from the area you're trying to cool with the fan. Or as you suggest, a Stirling fan could be powered off a stove and be used to force the smoke/gases out, but getting it started and having reliability and safety might be an issue.

[blake2go]

Will to post the plans? I have group of youngsters to keep busy!

Very nice job, I am amazed at the power.

[Keso12311]

perpetum mobile ? :) :D :D: 

[gibbo1112]

wow that is a cool water pump! im guessing is uses a marble valve type thing on the end of a the syphon hose right? that is a very clever use of the up/down motion of the engine

[approtechie]

@gibbo1112 No marble, just a check valve from a spray bottle. This clever idea is actually over 3,000 years old - the ancient Egyptians and Persians had versions of inertia pumps.

[gibbo1112]

@approtechie ahhh, yes that would work the same way, just less crude, nice one

[LtMaster1111]

Why the bucket with water is needed?

[canoncola]

@LtMaster1111 thats what I wanna know!

[approtechie]

@LtMaster1111 The fan isn't positioned properly on this engine to cool the upper cylinder, so I used water cooling. The engine pumps its own water. Cooling can be done by various methods.

[CPD0123a]

@approtechie wait, so not only is it powering a fan, it's also powerful enough to pump water to cool itself?!?!?!?!? HOLLY CRAP! I wonder how much a 2 or 4 cylender version could do... Hmmm...

Kinda self-defeating though-heating the air to power a fan that cools the air... Lol, who cares!

[approtechie]

@CPD0123a I've often pondered a multi-cylinder engine. The heat can be carried away by a chimney so the space doesn't get heated if that's an issue.

[approtechie]

@CPD0123a You can take a look at my newer engine, same size, same cylinder, but beta configuration with the diaphragm over the cylinder - drives a 20" fan at 800 rpm on propane, leaves this one in the dust.

[sonicxlc123]

free fan energy!

[InvalidMemberAccount]

isn't the fan blowing backwards? shouldn't the fan push air away from the motor or was that part of your design?

[approtechie]

@InvalidMemberAccount The fan should be blowing on the engine for cooling normally, but it would work to push it away as well. In this case, I could only fit the fan on one end of the crankshaft and it happened that the rotation was opposite to what the fan was designed for, although it still works pretty well. This was just an experiment to see if the engine would have enough power to even drive such a large fan.

[thedarkone2134]

@approtechie I don't mean to sound like a idiot but would I be able to put on of these on top of my wood stove and have it run from the heat given off? Could I in theory put on with a fan on top of my stove and have the fan disperse the heat a bit more?

[approtechie]

@thedarkone2134 My thoughts exactly! The best would be to cut a hole for the cylinder to fit into the firebox, but failing that, one could mold an aluminum block to hold the hot end, support the engine, and that sits on the stove to pull heat into the cylinder. I think this would work but I need to try this out to be sure.

[alexhouchens]

@approtechie This woodstove application is an incredible idea!

[approtechie]

@alexhouchens I tried it out and it worked, about 250 rpm even with just the cylinder sitting on top of the wood stove. With an aluminum heat sink to draw heat into the hot side I should think it would work a lot better. Will have to try it some time. Will post the video of the woodstove experiment soon.

[alexhouchens]

@approtechie I am very much looking forward to your video. I am building a model similar to this one in this video, and I had always planned to utilize a Stirling with a woodstove. I am purchasing a cabin that has a loft, and I intend on using the stirling from my woodstove to push the air to the loft.

[approtechie]

@approtechie You could also cut a hole in a short stove pipe section, insert the engine hot end, and seal it up. The rising heat and flames would probably work well to make it run. The stovepipe and therefore the fan could be positioned to move the air in the desired direction. You could also generate enough power for LED lighting at the same time. I think this would work in mud stoves as well.

[w3bguru]

very impressive!

[r43007]

i want to experiment. is it possible to sale me this unit

[approtechie]

@r43007 I'm sorry, I don't have any for sale yet. Maybe when I feel more confident in the design I'll make them available for sale.

[vegtervs]

wow dude! I am planning to do comparable things with stirling engines. but you're clearly a few steps ahead! awesome, a true inspiration.

[egokick]

dude, where did you get your materials from?

sincerely - egokick

[approtechie]

@egokick All of these materials are available from hardware stores, Walmart, Dollar store, and scrounging around for freebies. Except the bearings, which I found on the internet and ordered. Hope this helps. I plan to post a video with a sequence of assembly photos soon.

[Vebable]

This would be a good auto-tuned PC cooler.

[approtechie]

@Vebable I believe MSI was working on a tiny Stirling cpu cooler. Not sure if it's still applicable since the new chips run so much cooler. It's also not auto-starting, although there are self-starting designs out there.

[josephagp]

sweat stirling cant wait for the howto

[yellowmetalcyborg]

Nice engine, one of the best on the internet so far : )

[TK42138]

Brilliant! 

[WorldStove]

spectacular hot air engine! Your best to date.

[specallez]

Excellent! Even better that you're planning a how to video!

[kathrynjustice05]

PLEASE, Can you do a "how-to-build-it" video? I would like to know how it works.

[approtechie]

@kathrynjustice05 Still a couple of weeks away, sorry. It's coming though...