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This is a hot-air machine (stirlingengine), built with some old computer-parts (heatsink and the head of an old harddisk). This Stirlingengine (and all others also) works with a temperature difference between the hot bottom side (e.g. heatet with a candle) and the colder topside (cooled with the heatsink of an old 486 CPU) of an metal can (e.g.hairspray).
Simplified the engine works as follows: The candle heats up the air in the tin can. Hot air needs more volume. While we have a nearly constant volume in the tin can, the pressure rises up. This will affect, that the main-piston moves up. Coupled over a simplified crank, a second auxiliary piston (inside the can and so big, that his volume is nearly half the volume of the can) moves down. So the hot air moves from the bottom side along the big piston to the topside with the heatsink. It cools the hot air so that a vacuum occurs and the main piston will be drawn down. Now the auxiliary piston moves up and the cold air moves from the upper side to the bottom, were the candle heats it up again. This will occur solang, as the temperatur difference between the top and bottom side is great enough.

But now lets go. Have fun with this instructable.


Step 1: The Main Material

At first go shopping and buy canned-beer, coke, peanuts or something else which is useable as a container.

You see, its not really important what kind of can you prefer.

ATTENTION: ALL DIAMETERS are in mm (Millimeter). 1 mm is 0.03936996 inch
The raster of the paper in some pictures is 5mm

Furthermore you need:
2 Lithium CR2032 cells (3V) and 2 LEDs .
A pipe (brass or aluminium) with an approx. diameter of 20 mm and a length of 40 mm. I used an old chromed pipe from a shower (that part, where the shower-head was mounted).
An old CPU heatsink.
The head of an old harddisk.
Bare wire (1.2mm) and a drill also 1.2 mm
Wire 0.8mm (elctronic equipment)
U-profile alumnium 20 mm x 7 mm x 100 mm.
2 component epoxy cement (coldmetal stick) or normal 2 component epoxy glue.
A small piece of styropor/styrofoam.

Step 2: The Tools

Screwdriver,
Flat nose pliers.
Round nose pliers.
Scissor.
Wire cutter.
Drill machine.
Drill bits.
Tape.

No special tools.

Step 3: The Can

The can I use has a diameter of 50 mm. If nesessary, cut the lenght to 100 mm.
You have to generate a really good and straight cut. For this job I used a metal cutting disc.. Be careful. At least smooth down the edge.

Step 4: The Auxilliary Piston

This piston is inside the can. It's made of styropor/styrofoam. The height is approx.. 40 mm (a little bit less than half of the can's length) and the diameter is 5 mm less the can's diameter. You can form it with a sharp knife or with a hot wire (constantan). See the pictures.

For the piston-rod bend a 1.2 mm blank wire as shown in the picture and apply it to the piston. Fixate it with a piece of tape. For heat protection, wrap the piston with aluminium foil.

Step 5: The Cylinder -part 1-

For the cylinder we cut a piece of 40 mm from the brass pipe. Smooth down all edges and the inner side of the pipe. The inner side must be very very even, I used toothpaste for the last finish.

We make the piston of epoxy, with this cylinder as the form. For this, oil the inner side very well.
Then place it on baking paper.

Step 6: The Main Piston

Cut a piece of 10 mm from the epoxy cement and knead it very well (~ 1 minute) until the epoxy has a homogene colour and gets a light warm. Fill it into the cylinder and compress it with a wooden staff (which must be oiled before using).
When the glue is hardened, press it out from the cylinder (use the wooden staff). Use a hammer and hit the wood carefully. It's not so easy, but it works.
Now cut the uneven Part of the piston with a saw. Smooth down the piston and the cylinder very well. Smooth down the piston so long, until it moves very easy in the cylinder.

It is very important that the piston easily moves in the cylinder and seals this, nevertheless, very well.

Drill a 1 mm hole across the bottom side of the piston. Attach a 0.8 mm wire with two isolation parts (for centering). Don't forget the piston rod. This is made of 0.8 mm wire. At the ends make a very small loop with the round nose pliers. The length over all is 60mm.

Step 7: The Cylinder -part 2-

If available, use a little piece of copper-clad Pertinax (electronic equipment). Drill a 5mm hole in it. Solder the pipe with a soldering iron on the copper-clad side of the Pertinax.
Then solder the whole cylinder the same way.

If you don't have Pertinax, you can use a copper or brass sheet.
You can also use other stable materials and connect the parts with glue (e.g. epoxy).
The temperatures at the cylinder will not increase very high.

Step 8: Preparing the Heatsink and the HDD-head

Drill a 1.2mm hole exact in the center of the heatsink. This is the hole for the auxiliary piston-rod. This rod is made of the 1.2mm wire. If you use a new drill, normally its diameter is a little bit greater then the nominal value. My 1.2mm drill was exactly 1.25 mm. So the rod can move easy and is also tight enough.

(My first hole was not good. So i make a bigger (5mm) hole in the center of the heatsink. Then i close this hole with the epoxy-cement. When its hardened, i make a better 1.2mm hole.)

Drill a second 4.9mm hole near the egde and press the little 5mm brass pipe into this hole .

Make two loops from the 0.8mm wire and fixate it at the heatsink.

Drill a 1.2mm hole across the axis of the HDD-head (see picture). The head is made of aluminium.

Step 9: The "crankshafts"

For the two crankshafts bend the 1.2mm wire as shown on the pictures.

Step 10: Assembling the Parts

1. Attach the gasket to the heatsink. Double-sided adhesive tape may help you.
2. Put the auxiliary piston into the can.
3. Mount the heatsink with the 4 screw/wire combinations to the can. If you won't disengage this connection, you can glue the can direkt to the heatsink (in this case you don't need the gasket and the screw/wire combinations). Take care, that the rod with the auxiliary piston moves very easy in the heatsink hole.
4. Mount the cylinder to the brass pipe of the heatsink. Blow into the cylinder, to check that the construction is tight!
5. Connect the U-Profile to the heatsink.
6. Connect the HDD-head with the U-Profile.
7. Mount the main piston-rod and the crankshaft together.
8. Put the piston into the cylinder.
9. Crimp the wire of the crankshaft a little bit, so that it get stuck in the 1.2mm hole of the HDD-head.
10. Connect the second crankshaft (auxiliary piston) also to the HDD-head. The angle between the crankshafts shall be 90 degree.
11. Connect the rod of the auxiliary piston with a thread to the crankshaft.
12. Solder this construction (see picture) to the main piston crankshaft.
13. Now your sterlingengine is ready!

Step 11: More Pictures of Some Details

Attached you find more pictures of some details. Maybe this makes some things clearer.

Step 12: Your Sterlingengine Is Ready !

Now work is done. Create a simple stand for the engine, place a little candle under the bottom and the engine will run. If not, investigate that all is tight and the rod and the piston moves easy.
um hi i liked yur instructable alot n m mking it fr a science fair....i have to make it in 6 day i jst wanted to ask u some questions.....sum of the thngs r nt really available in india....so if u cud jst tell me some alterantives n some detailed instructions it wud b great :)
Awesome.<br><br>&gt;insert jaw dropping sequence here.&lt;<br><br>&gt;Insert jaw lifting sequence here.&lt;
Does this thing go faster if u apply more heat????
This engine is driven by the temperature difference between two parts of the engine. More heat difference = more speed
it should
Use small dc motor generator power for Led will be much Green and fun.<br>But still very good idea.
I like so much<br />
If you added a little coil and capacitor along with each LED with a few magnets situated near the flywheel, the motion of the flywheel could generate the power for the LED's.
trying your idea<br />
Good idea, since a hard drive has already been dissected there would be the option of the (voice) coil (assuming it can be extracted without destroying it - sometimes they are deeply embedded) or the stepper motor with some diodes to convert the AC to DC (or just wire a whole lot of LEDs across the four coil lines in different ways for a strobing effect). Probably a bad idea to spin the stepper around at that speed, not to mention difficult, So that option would probably work best with a belt linkage to the axle of the engine, the hdd platters could even be used to lend some inertia to the axle. drew
Congrats! Nice work!<br />
wicked man, this is really really awsome!
good luck!
Imagine a V8 Stirling engine? I have to go try this now.
i realy like your stirling engine an am going to make it but i have a few questions before i start, so if you could message my user acount or post the answers here that would be nice. Q1: with the epoxy that makes the piston, what brand is it? Q2: where can i find a hdd head from? Q3:where can i find a heatsink from?
Q1: with the epoxy that makes the piston, what brand is it?<br/><strong>I don't know</strong><br/>Q2: where can i find a hdd head from?<br/><strong>An old harddrive laying around</strong><br/>Q3:where can i find a heatsink from?<br/><strong>An old heatsink laying around</strong><br/><br/>My best suggestion if you don't have these just laying around--go to a thrift store until you find an old pc--then harvest it.<br/>
Note that it actually doesn't even have to be a putty "kneading" epoxy, it can be a 2 part pour/mixable epoxy. It's all about making SURE it doesn't Stick! (If you use 2 part liquid epoxies, 5min epoxy works the best I've found) Also note, that there's probably one angle that the piston will slide smoothly if done properly, so there's no need to sand it down. BUT, if you can't get it to go smoothly, it's ok to sand it. Anyways, interesting job using the putty epoxy, I never thought it would work when I made mine a while back.... hmm... probably a lot easier to work with too... Oh, and careful with that Styrofoam, if you run it too long it'll melt. I bet some lava rock would work pretty good though... cool pictures by the way! like the instructable!
Why does the brand matter? Just buy a decent priced one. Your can find the HDD head from a hard drive. Your can find the heatsink from an old computer. If you can find an old computer that is'nt needed you can salvage the HDD head also. If you cannot find an old computer you could buy a heatsink online.
huh...I will start gathering the parts ASAP...it looks like a cool toy
Stirling engines are awesome! I can't wait to see one of these: <a rel="nofollow" href="http://www.msi.com/index.php?func=newsdesc&amp;news_no=591">http://www.msi.com/index.php?func=newsdesc&amp;news_no=591</a><br/>
W00T! Nice job. I like how this is like a steam piston style.
it would be awesome to add multiple LEDs along the length of the arm (of different colors) like <a rel="nofollow" href="http://www.technomoves.com/images/2-5_led_spinner_globe_300.jpg">this thinger</a> and watch it spin in the dark<br/>
That's true. But it should only be a suggestion (and.... I had only 2 lithium cells).
it should only be a suggestion? im afraid im a bit confused...
can you power it off a shining light bulb?
Yes, it's possible. I tested this with a 12 V, 35W(att) Halogen-spot. If the distance between spot and bottom is approx. 1 inch, it will run.
will it run quickly?
No, not very fast. I think it will run with approx. 60 turns per minute.
Can you power it from the heat present on a hot water pipe?
probably not
Is there any issues with cutting a pressurised container?
Don't cut a container under pressure !! It's much safer to use container from canned-beer, red-bull, coke or so. I have revised the instruction (step 3).
probably that it's filled with highly flammable chemicals that can ignite on a few simple sparks... try to keep the can open (by pushing the button down with a weight or something) overnight before you start cutting.
I like this sterling engine design a lot, thanks for posting this! We should call these LED spinnies instead of throwies.
Thanks, that's a good suggestion. But - if you power the sterling engine with much more heat, it's possible that the "spinnies" becomes "throwies" ;-)
Nice project, but the question i have: is the weight in the back supposed to act like a flywheel?
No. This is only to compensate the weight of the auxiliary piston.
i wonder how fast this could go if you made the heat source more powerful
i've wanted to build a simple stirling engine for ages, but there's one problem- all of the simple engines look awful and the good looking ones are complex- But not this one..
Very interesting!
5/5 and heart !
If I were you, I'd remove the "edit this step" link from substep 3.
WAY COOL
I like Stirling engine great works!
Wouldn't this be a little to big to be considered a throwie.
very interesting! I prefer the slow rhythmic movement. it's hypnotic. I bet this would look amazing in the dark, this slow spinning light. How about adding a collar around the candle to black out it's light (and maybe as a wind guard!) Neat project!
that would be a good idea to block out the unnecessary light. however there needs to be vent holes along the top (exhaust) and bottom(intake) so the candle will stay lit or else when you put the collar around it, it will simply die out after using all the air in the chamber. so yea with vent holes it should work.
Wow.... This is awesome. I think this would be great for looking at when you're bored. I agree with mikeasaurus, it IS hypnotic... I think this was a good way to make a motor. Maybe you could make another one with more..... accessible materials? :P
those materials a fairly accessible, just go to the home depot

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Bio: My name is Volker. I live near Osnabrueck (Northwest-Germany). My profession is an electrotechnical engineer. I like to go on journeys and take many photos ... More »
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