The Stirling Engine, absorb energy from candles, coffee, and more!

There's energy all around us that's just waiting to be tapped into. Whether it's hot coffee on a cold day, light from the sun, scented candles, waste heat from electronics... there's power to be had! How about we turn it into useful power? Step in the sterling engine.
Ever put a tightly filled balloon in the freezer, then come back and see it largely shrunken? Once you bring it back out into a warm room it expands again. Now what if we could use that expanding and contracting for moving a piston... and you've got the general idea. If you heat the air, it expands, if you cool it it contracts. It's a very simple idea, for a very simple engine.

let's get building!

here' s the video of the build and the engine working!

Step 1 Materials

Required tools:

hacksaw
utility knife
drill
plyers (long nose)
wire cutters
drill bits 1/16, 5/32, 1/2-3/4
drawing compass
ruler

Materials:
CD and case / large plastic jar lid
10x5 inch piece of steel or aluminum two 5x5 pieces are fine, needs to have some thickness
CD tower (or even better) a LARGE 5 inch wide glass bottle. (see picture)
EPOXY (JB weld/ JB kwik AND regular, cheap epoxy. If it says non shrink, don't get it!)
    *there's been a lot of issue with epoxy, I never realized different epoxies would cause such a difference, so I've added a picture of the epoxy. Here's one place to buy it: www.amainhobbies.com/product_info.php/products_id/37084/n/Bob-Smith-Industries-MID-CURE-15-Minute-Epoxy-9oz  Hopefully this clears up the issues!
wire (welding rod is preferred, Stainless steel is best) 1/16 inch stainless or 1/8 steel - MUST BE SMOOTH and straight!
7 inches of PVC pipe
Foam board (5x10 inches or more, two 5x5 pieces are fine)
3/4" copper pipe
oil

(optional)
hotglue and glue gun
fan weights

Comments

[micraman]

GREAT VIDEO! It was very clear and thorough. I love how you used resin to cast a perfect fitting piston! Love it.

[ZeroAks]

Is there a reason that hot glue works better? For me, I've found that it often has trouble adhering to the metal, and breaks free easily.

[shiv_rulz]

i get tht the heat is because of heating it with a candle or something ... but wht about the cooling part ...!!!! is the room temperature enough to cool it..! plz letme knw .. cheers :)

[knexfreak32]

f you don't want to spend 10min.-20min. making the wire straight. then chuck it up in you're drill grab the other end with pliers. give it a good spin and there you go.works like a charm.

[fastexitbe]

Thank you for your wonderful Stirling engine instructable. The video was excellent. I am having trouble with the epoxy piston sticking to the copper pipe. I have tried to remove any burrs on the ends of the copper pipe by using a utility knife and have cleaned the pipe inside with Windex as suggested. Then I use one of the following Pam Grilling Spray, Remington Gun oil, or White Lithium Grease to lubricate the copper pipe. I then use either BSI Mid-Cure epoxy (used in the instructable) or BSI Slow-Cure epoxy. The BSI Mid-Cure epoxy refuses to come out of the copper pipe even with the pressure of a C-clamp. The BSI Slow-Cure epoxy comes out of the copper pipe with an insane amount of pressure from a variety of C-clamps, pliers, etc. There does not seem to be *ANY* shrinkage in the epoxy and also it appears to be binding to the copper pipe no matter if I use a little or a lot of the lubricants. I have heated the epoxy as suggested and also tried it cold. The Saran Wrap plastic film works very well. The BSI Slow-Cure epoxy pistons that I was able to get out of the pipe by using extreme force look quite smooth on all sides, however they would never be able to be placed back in the pipe by hand. Any ideas what I am doing wrong?

[crockman1]

trythis:
buy (or make) and heat it with solar magnifying frensel lenses:

http://www.amazon.com/gp/product/B001TLJXJ8/ref=pd_lpo_k2_dp_sr_2/179-1042328-6808164?pf_rd_m=ATVPDKIKX0DER&pf_rd_s=lpo-top-stripe-1&pf_rd_r=048JWZX1DNH32YAV99BF&pf_rd_t=201&pf_rd_p=486539851&pf_rd_i=B003JOS5VK

[tobyscool]

on the first picture in step one says you need a balloon and a motor ???

[nick.supron]

ya whats with that?

[nick.supron]

dose it matter the size of the PVC pipe?

[lithiumnights]

one of the best sterling engine makes i have seen

[jaipai]

Very Nice .
Here is some more info on Stirling engines.
A Small Free-Piston S t i r l i n g R e f r i g e r a t o r
http://www.archive.org/details/nasa_techdoc_19860012245
by
A. K. de Jonge
(14th I n t e r s o c i e t y Energy Conversion Engineering Conference,
Boston, Mass, Aug. 5-10, 1979)

[x-tian]

i'm stuck with a pipe filled with epoxy. I think it's bulletproof. (it was 1 minute epoxy btw, it almost burned down my house, but it didn't shrink)
what should i do?

[justindouthat]

does it have to be cooper on the bottom or could you just use steeal

[engineer#1]

I have aluminium in thin sheets does the thickness matter?

[Mr. Z]

Would styrofoam work for the foam board?

[theruss007]

Instead of using steal or aluminium for the plates, could I use copper instead?

[thecheatscalc]

Definitely, Just keep in mid that if the copper plate is flimsy, it'll rob the engine of some of the power, and may mess with the crankshaft.

[cassanovah69]

Can I get away with using 1/2 id copper tubing? Or will I have to make the cam too deep for the motor to run right?

[Mckye]

I am sorry, but I feel that it is a gross injustice that I did not see this comment ten times in the first page. The creation and execution of that video was beautiful in a way that is difficult for an educated man such as my self to put in words. I thank you from the bottom of my soul for making something so incredible in a place so ordinary.

[TANZMEISTER]

Instructables is no ordinary place. Quite the contrary, Instructables is a haven in an apathetic sea of disposable junk!

[Jocieposie]

This lookes really cool~ Im trying to find a way to use the idea and incorporate it into my science project, but I'm still a little confused on how everything works the way it does. Can I have a little explanation on how this thing functions?[: Thanks.

[TANZMEISTER]

Google is your friend . . .

[Cobalt59]

Awesome! The music and the engine parts that move in time with it make it look like "How it's Made". +1

[hippyrob]

Love the dramatic music. Your video rivals that of Profanisaurus in the awe department. Thank you for posting such a clear instructable on how to make a stirling engine. Your video shows the construction process really well and delivers a solid understanding of stirling engines. (I am making one out of recycled materials.)

[hayme]

uh hey can i use cement, hardening clay or some melted rubber for the piston?

[Argon317]

I casted the piston like you said however it is impossible to push out of the copper pipe. I used this type of epoxy

http://www.loctiteproducts.com/p/13/6/epxy_qset_s/overview/Loctite-Epoxy-Quick-Set.htm

I realize you said not to use the 5 minute kind, but I did not see any thermal contraction issues when it was setting. On the contrary the epoxy seemed to bond to the copper. Is this because I did not put a sufficient coating of oil on the pipe? I used wd-40. I also pre-mixed it before pouring it in.

[David97]

Did you use a pipe cutter to cut the pipe?
If you did You need to run a file around the inside to stop the edges catching.

[ttbmtk6]

Does anyone think there would be a problem with using a smaller diameter copper pipe, as long as the wire for the piston doesn't hit the side? I'm planning on using some 1/2 inch (diameter from the inside walls; I'm not a plumber!) pipe that I have laying around the house. I actually thought it might increase the pressure on the piston and so lend it some more force, but I'm not a physicist either, just a physics student, so what do I know? :) Any help is appreciated!

[Take-Notes]

Great instructable

[polerix]

Words cannot describe how cool this is.

[Dr Qui]

I bought some epoxy putty in Poundland, 5 times cheaper than everywhere else.

I mixed all of it and packed it into the plastic tube it came in, it does not stick to the plastic and is easy cut out once it hardens.

 The hardened epoxy bar reads 25.1mm on the calipers or 63 / 64 in old money.

I have just bought a mini lathe and the first project I intend to do is a Stirling built from scavenged PC parts.

[horshak]

I'm feeling like a dummy after reading all your comments and seeing videos on your working engines. I used 1/16 th aluminum for my top and bottom plates. I used brass plates for my stand. I have made my crankshaft out of stainless thicker than 1/16th but under 1/8th in My rods and ends are lightweight model airplane parts. .I have tried to cast my pistons twice with quick epoxy and I'm making my 3rd piston out of JB weld. Everything has been made twice with better quality control. It's ballanced and spins freely and looks quite good. Problem, it won't run at all. My wife says I sound like a hamster in a wheel in the kitchen. Please help!

[walkercreations]

Do you by chance have any pictures of your design? I was thinking about using Radio Control Aircraft parts on my design as well and would love to see what you came up with.

[thecheatscalc]

Hey, sorry to hear that you're having trouble! Would you mind taking some pictures? A side picture, a top picture, and anything else important. Maybe even a quick video of it running (or it not!)

Once the JB weld sets, take the copper pipe and hold it up the the light once you've removed the piston, clean the pipe, and put it back in. Check to see how much light you have coming through. If there's a lot, or the piston doesn't slide freely, then there's an issue. Otherwise, put it in the engine and see how well it works.

Also, don't attach the piston to the crankshaft and put the bottom plate on the flame. Does the piston move up? if not, your engine is probably leaking somewhere.

Finally, if you put it on the heat, the engine WILL pressurize, and the piston will move up, and might stay there until the pressure equalizes a bit. Keep spinning it for a few seconds (if it's not even trying by 20 seconds or so, pull it off, something might be wrong.)

[horshak]

found leaks in the displacer by submerging the engine to the top plate in a glass bowl after removing the piston and using my wifes turkey baster to blow air in the power cylinder. Now I get the piston to rise at times but the piston (epoxy) gets sticky and won't work after 1 or 2 tries. I kept sanding down the piston till it wouldn't work any more (the 6th piston).  After heating water in a coffee cup several times in the microwave I had the water explode and I boxed the engine up and dropped it off at a machine shop for them to machine me a aluminum piston. I am now waiting for it to return.

[thecheatscalc]

Sorry about all the trouble! I hope it works well this time! If they're machining a piston, you might need to get a matching cylinder.

I hope it all goes well!

[horshak]

thank you for replying. I just cast my 6th piston as both I made with JB Weld were bad. I used 60 min epoxy this time and got what looks to be an excellent piston. Engine still doesn't work. I went around the displacer looking for bad joints with the epoxy to the bottom plate and tried to seal up questionable areas and reduced the crankshaft dips as was someone elses video. Still doesn't work.I tried your suggestion of disconnecting the piston and don't see any movement. I am now going to submerg the engine in water and try blowing thru the piston cylinder to see if I can see bubbles indicating leaks.......................horshak

[satellitedanny]

How long is the pipe? I can't size it up and I only have a limited supply of spare pipe. I don't need an exact measurement, I just need an approximate measurement. Thank you!

[magiccowy]

how much is this in cm the calculator doesn't seem right

[magiccowy]

Could you use fimo