Instructables
Picture of Simple coke can engine
This is a simple coke can Stirling engine you can make in under an hour. No epoxy or RTV needed, just super-glue. It's all supported by steel wire, with spade connectors for all of the bearings.

Important note: It has been found that aluminium drinks cans need additional cooling around the top because the aluminium is so thermally conductive. Use steel cans if you can, such as Pepsi, Tango etc. Scraptopower has many other plans for simple Stirling engines, have a look here.

Thanks to David Williamson for the diaphragm design/ construction method. Check out his website here!

Materials1 Coke can
  • Steel wire wool
  • 1.6mm steel wire
  • Spring paper clip
  • Normal paper clip
  • 0.4-0.6mm fishing line
  • Super glue
  • Thin cardboard from a cereal box
  • A balloon
  • 6.35mm electrical connector/spade connectors .
 
Remove these adsRemove these ads by Signing Up

Step 1: Open the can with a can opener

Picture of Open the can with a can opener
Open the top of the can with a can opener.

Step 2: Bend a paper clip

Picture of Bend a paper clip
Bend a paper clip into this rough shape, this is so that you can tie the wire onto the displacer later on

Step 3: The displacer

Roll the steel wire wool around a bic pen, when it's a little bigger then the can opening, stop rolling the wool and cut it to size. Cut it down to about 2/3rds of the height of the can. Thread the paper clip you formed earlier through the centre of the steel wire wool. Tie on about a foot of fishing line to the hook in the paper clip. Squeeze the displacer into the can. It's a tight fit, but it can be done

 

Step 4: The diaphragm

Picture of The diaphragm
SimpleCokeCan16.JPG
SimpleCokeCan21.JPG
SimpleCokeCan25.JPG
SimpleCokeCan27.JPG
SimpleCokeCan28.JPG
SimpleCokeCan29.JPG
SimpleCokeCan30.JPG
Draw two circles on the cardboard about the same diameter as the opening in the top of the can. Don't pierce through the cardboard with the point of the compass. Inflate balloon then super glue the cardboard disc onto the balloon, there's usually a slightly deformed part of the balloon - this is roughly the centre. Glue it on here. Deflate the balloon and cut off the neck.Turn the balloon inside out. Cut off the balloon around the centre.Glue the cardboard disc over



1-40 of 163Next »
christpher3 years ago
I gust watched tow helicopters go by woooooooooow
8v923 years ago
Trying to figure out why this engine runs is like figuring out why a bumble bee flys, it should not run but it certainly runs quite well. The counter weight in the center seems to resonate and the flywheel is low mass but high inertia. I am not an expert but there are principals at work here that need to be studied. This is a great example of thinking outside the box.
The principle is quite simple. If I may.... There is a displacer inside the can.
This displacer moves up to allow the air within the can to make contact with the hot can bottom. This expands the air which drives the diaphragm up due to expansion. The displacer then drops to the bottom of the can which insulates the air from the heat thereby allowing the surfaces not exposed to the heat to cool the air which allows the air within the can to contract.
The REALLY cool thing about sterling engines is if you drive the shaft instead of the other way around, it becomes a heat pump! Not bad for 1880's tech!
I did not see the fishing line going to the displacer in the movie so I thought it was resonating somehow. I still think it is a good design and would work with multiple cylinders. Perhaps an affordable and practical vehicle could be built using a stirling engine.
rwcrocker3 years ago
Very cool! We built it today. It took a little more finesse bending wire than I had anticipated. If you don't balance it well enough, it wobbles like crazy on the wire legs even if you're holding the base.

We added a 15 mm strip of wet paper towel around the top of the can to act as a better heat sink - it helped a lot.
Thanks a lot for the great instructable!!
scraptopower (author)  rwcrocker3 years ago
Wooo! First person to build this ? Please share some photo's if you can :)

The paper towel is a good idea!

Thanks!
Middle School Science Fair, here I come!!!!
Awesome!
I had never even heard of a Stirling Engine until this instructable.
My kids and I will have a blast (in a good kind of way) with this.
I think it's AWESOME that you are introducing your kids to this!
Not only is this device classified as an external combustion engine and is truly a flex fuel technology which can even run on solar or geothermal heat.
In fact, any heat difference between the "hot cap" and "cold cap" will make it run. This goes all the way back to 1880's Scotland and I have read that it was devised to take the place of the dangerous steam engines used in coal mining at the time. Not a bad job of design by a monk of all people.
Ther is a wealth of history associated with this device.
One last thing, it has been said that this device is one of the most thermally efficient engines ever devised. Good luck with the Science Fair!
ssuseelan8 months ago
Hai wit respect
I like to know if I can replace the 'fine steel wool' thing here.
I am unable to find it.and also can you suggest me a way to find it? please!

thankyou
ninjablade8538 months ago
Would ring terminals do I couldn't find spade connectors
great instructable.one question.can i use cotton instead of steel wool?in our county steel wool is not available.so..............
tojo131 year ago
Where and how does the displacer connecting rods go?
rikardom2 years ago
Awesome!
tobune2 years ago
Very good concept. Trying to make it reality now.
tokin2 years ago
Cool!
mattle tokin2 years ago
Yes it is!
stumitch2 years ago
fantastic! i want to build one!
teniva2 years ago
Just love it and I certainly must try it
can i use a steel wire instead of fish line and tell me how it works??????
begunia2 years ago
Amazing work my friend!
kuruting2 years ago
Amazing...
lepar2 years ago
Awesome work. Thanks for sharing it with the community.
merkuri22 years ago
Interesting I must say.Trying to make it now.
kokina23 years ago
You are awesome and creative!
torina23 years ago
Excellent work!
Chowmix123 years ago
I really want to do this project. I have all the things but the wire. Would paperclips work as wire? By the way, would a few drops of water make Stirling engines more effective? I know steam is 100 times the volume of water.
scraptopower (author)  Chowmix123 years ago
I wouldn't have thought paper clips would be long enough, even un-wound. You could try adding another coke can on top for the bearings like my other instructable "make a coke can Stirling egnine" . You can get this kind of wire at garden centres and the like, it's not usually expensive, don't get the really thin 1mm stuff though as that won't work.

My engines that have had small water leaks all splutter to a quick death, maybe it would work but you need to be quite precise in the amount of water :)
the paperclips worked for the crankshaft, I made a flywheel of cardboard and glued it onto the crankshaft. For some reason I couldn't get the engine to work.. I gave up on it...
sandra-13 years ago
Very cool! We built it today.
MCzone3 years ago
learn to measure
how does 15 cm get that far
you made me waste 30cm of wire.
MCzone MCzone3 years ago
oh im sorry i made the mistake
scraptopower (author)  MCzone3 years ago
Use it for the connecting rods.
I started using it for the stand and the loop above the basket <:(
wiinick MCzone3 years ago
I almost id that too, but my base looks nothing like the picture, but does it work, yes.
MCzone wiinick3 years ago
I never did get that tin can working, but its cool
I have tried to assemble a Simple Coke Can Engine, but after several attempt, I failed, so please let me know how would you help me if i become a paid member.
scraptopower (author)  nishi biswas3 years ago
Authors on this site are not paid, so being a paid member will make no difference.

Which steps are you having difficulty with ?
pauli23 years ago
Amazing work have you done.
scraptopower (author)  pauli23 years ago
Thank you.
antonio233 years ago
I found this project very interesting! Trying to make it now.
1-40 of 163Next »