Mini Stirling- JB weld piston

[IronGoober]

@bassonmyolmonster I bought it at a hobby store, I'm not sure what it was intended for.

[tahboobi]

exuse me sir, can this engine produce enough power to move a small toy car by connecting the wheel to a shaft?

[IronGoober]

@tahboobi I doubt it, unless you geared it down A LOT. Then it could work.

[tahboobi]

@IronGoober thank you, ill consider that 

[IronGoober]

@tahboobi If you geared it down enough, then yes, you could move a small toy car. It would be a slow car though ;)

[tahboobi]

@IronGoober alright ,, thanks very much

[technology49]

The big piston mustnt be tight,right?

[SlingingIronGoober]

@technology49 Yes, the displacer piston needs enough clearance for the air to be displaced from the hot side to the cold side and vice versa.

[asdfkjaskldalsdfa]

it's incredible, if I don't see, I don't believe,,,, it's so small !!!! congratulations.

[flowerman2705]

Become a member of INSTRUCTABLES and put this project on to it would be very helpful!

Thanks :-)

[flowerman2705]

Hey,

Nice video and a sweet stirling engine but i have a question. When you casted the power piston with jb weld, when you got the piston running freely inside the cylinder could you see tiny air gaps around the piston inside the cylinder? Thats what I got and im wondering in my stirling engine will still work?

Thanks

[IronGoober]

@flowerman2705 I never actually checked, I should of only had a few thousands clearance. If you put the piston in the cylinder and plug the other end (like with your finger or hand), the piston should slide slowly down into the cylinder, not fall, if it does, then you should be fine.

[Scandahuvian]

That would be good to use on a wood stove in a small cabin to encourage circulation.

[yoyohoes]

can u make a vid on how ot make it

[rostlaur]

To make the piston with J-B Weld:

I wonder if refrigerating or freezing the brass tube (out from the freezer with ice around, cubes or frozen in the center of a simple block of ice, etc...) would shrink it just enough (or too much) so that you pour the J-B Weld into it, let it cure in the fridge.

Take it out of the fridge when the J-B is rock solid, heat the brass tube in boiling water; that will expand the copper tube slightly and maybe free the piston and make easier to extract?

[IronGoober]

@rostlaur Yeah, that might work, however, JB weld or even JB Kwik take a LOOOONG time to cure when the temperature is lower. Might take few days to cure. Worth a shot though if you have an extra spot in your fridge.

[memo0586]

yo that is awesome dude!

[ratkfizzle]

does the foam displacer create a seal...is it solid? Also is the displacer rod tube (in the top plate) airtight with the displacer rod? A response would be much appreciated,Thanks!-Taylor King

[impazzitoinvolo]

Very nice you are an artist!!! congratulations!

[momodragon]

i tried doing one like this and i tried one with a tin can... it never worked...

[harishatutube007]

dude how u sealed the rod coming out of the foam?? one more doubt; is there any diff in stroke length of the two pistons??

[hanbaal]

Oh, i see. Not so easy to heat it with the sun to that heat but ill bet that thing doesnt waste much of the energy input. Look at it go!

Ah, i get what the ice is about. If you put it in the fridge i assume itd go nuts?

[IronGoober]

Well, it runs on a temperature differential. So, the hotter one plate, and the colder the other, the faster it goes. It's actually not that efficient...less than 1% of the heat energy gets turned into mechanical work :( But it sure is a cool engine! And there are Stirling engines that run off the sun out there.

[hanbaal]

Holy poop on a stick!

Your just using the heat in the jar?!!

[IronGoober]

It's filled with hot water (Microwaved until it started to boil). So it is probably near 90 degrees C.

[bleachworthy]

How did you make the piston? pour it in the cylinder let it dry then force it out?

[IronGoober]

Exactly correct sir! I just left the cylinder taller than how much I poured in, then I turned the cylinder over once it dried and whacked it with a punch. It took a bit of maneuvering, but I got it out.

[Fonta1984]

Well done! Is the displacer in styrofoam? Are you sure the high temp in the chamber will not melt it?

[IronGoober]

Well, depends on how high of a temperature you try and run the engine at. If you go much hotter than boiling water, yeah, it will melt. But boiling water is fine.

[1972FordF150]

cool!

[pimpinpenz]

wow how did you do this?

[randommagnum]

It needs a bigger propeller...it can handle much more load! It's a great machine.

Now I have to ask, what is the story with the zig-zag I always see in connecting rods?

[IronGoober]

Yeah, this was the best propeller I could find that was still small enough. The zig-zag is just because I made the rods too long and had to shorten them, I think that is usually the case, and then the length is easily adjusted.

[radziozo12]

hi! good greeting from Poland ! nice idea about working piston :) but what kind of material is cylinder made ? glass is so expensive ( at least in Poland ) so what is it made of??

[IronGoober]

I put this in the video description, it is made of brass.

[radziozo12]

yes that i see but i ask what is around the biger piston ? it is transparent material, it is glass ?

thx for your answers

[IronGoober]

Ah, I see, you mean the displacer piston. That was cut from a small plastic container. I bought it at a sporting goods store (REI) and then cut it apart with a Dremel tool.

[gingischan1951]

thank you for subscribing!Your ringbom generator is wonderful !gingischan

[jovallmen]

Hi from swiss country.

With stirling engine, cold wind is energy.

And please, set your's one on the table,... before it flies away ! :-)

[afleececooper]

Great engine... clever solution for the piston, must be a fine fit...

What do you use to lubricate it?

Cheers,

AC :)

[IronGoober]

It is dry running, if the epoxy and cylinder are smooth then it runs pretty frictionless.

[donpag89]

what material are the pistons?

[IronGoober]

JB Weld epoxy.

[jessekarate08]

read the name of it again

[donpag89]

the problem was that i didn´t know what JB weld is.

[ratkfizzle]

@donpag89 JB Weld is a 2 part epoxy that you can find at about any hardware store and sometimes,grocery stores to. It is very easy to use because there is two tubes of goo and you just mix even parts of each on cardboard or something and viola...there's your super awesome epoxy!!

[jhigu]

amazing little engine you built. im trying to build a smilar sized engine for my school design and tech project and i was having trouble desiding on the dimentions on the displaces chamber : diameter and hieght and also the diameter of the con rod. i would be amazing if you could please comment back the details of you engine, many thanks

[IronGoober]

The displacer cylinder is 1.25" with a displacer clearance of 1mm or so. Height of the cylinder is about 5/8"(a bit more). Displacer height is about half of that (good rule of thumb to use) Piston cylinder is made from 1/4"(OD) brass tubing with 1/32" wall thickness, so a 3/16" ID. The displacer rod is .032" music wire and the gland is 1/16" brass tubing (OD).

[DailyMovie]

Thanks for your complete answer.. So, to look a little deeper into this.. How might you compare this boiling water.. to the potential fuel you might be using to drive this motor as an eco friendly engine. What might be heating this water, or how?

[ppardee]

The big problem with using stirling engines in a real-world application is that they have a fairly high start-up time. The larger the engine, the longer it takes to get it running at full speed. The effect can be observed in this small version. Imagine having to wait 20 minutes to go anywhere in your car. This could be offset by using a stirling-electric hybrid though.

The water is just a heat source. In a real application you would use gas, coal, propane, wood etc...

[IronGoober]

I really like the idea of a stirling-electric hybrid. I just wonder if you could make an engine with the right capacity small enough. Seems to me, the only way to make it work would be to have a very streamlined car so it takes less power to drive. It would make a very efficient vehicle though.

DailyMovie, Another major disadvantage to these engines, is that with as small as a temperature differential that hot water provides, the efficiency is very low...

[electrique527]

Oh, but that is not true!

Philips designed a sterling engine for the Ford Torino in the 70-ies, it was ready to run at 150 HP within 30 seconds.

The problem was the control of the engine to get a smooth ride.

If they would only make the engines now to power a generator for hybrids.... :(

[DailyMovie]

so maybe I'm missing something, but, what part does the jar of water play in this? Why does it start working when placed on the water?

[IronGoober]

Stirling engines work off of a temperature differential and the water is near boiling temperature. So it heats up the bottom plate rather quickly, the top plate is at room temperature, and away it goes.

[trossachs2003]

Thanks for the reply - I've never seen JB weld here in the UK but I'm sure there must be something similar.

One other question - is there any reason that your conrod is so long. Doesn't that make it unstable - might even fall off its cup?

Also right at the beginning we can see to the right another, larger engine. What is that one?

[IronGoober]

The longer connecting rod reduces side friction because it reduces the angle difference between the connecting rod and displacer rod (you know, vector math...) But the reason it fell off it's cup was it was vibrating from the lack of balancing... longer connecting rods are generally a good thing. (except for saving space.) The other engine shown is in the other 2 videos I've posted.

[trossachs2003]

Thank you mr Goober. Makes sense.

[trossachs2003]

Aww cute

I'm trying to make my own.

I'm guessing JB weld is some kind of filling compound..

What did you use to lube the piston? and how did you get an airtight seal where the displacer rod passes into the displacer cylinder.

tx

[IronGoober]

JB weld is just an epoxy. I didn't use anything to lube the piston, which is why I chose JB weld, it is a high quality, high strength epoxy that can even be machined. It is pretty frictionless in a brass cylinder. The displacer gland and rod are just a close fit, that are pretty frictionless, I used a .032 inch steel wire and a 1/16 inch outer diameter brass tube for the rod and gland respectively. (

[Alfrunk]

Meanwhile, cancer goes uncured. Ridiculous.

[IronGoober]

Well then get on it!!!

[Alfrunk]

How do you sleep at night, seriously??

[IronGoober]

Quite simply really, I close my eyes and relax...and voila sleep comes...

[Alfrunk]

My God, I cannot believe what I'm reading.

[aboomanation]

prevent cancer! stop eating heavily processed, sugar laced, and genetically modified food!

[Alfrunk]

NEVER!!

[tikifish28]

When I tried making that same JB weld piston, when I finaly got it out it did not go into the tube that nicely and made too much friction could you tell me why that would happen?

[IronGoober]

Did you sand the piston down a bit, it won't work if you don't? You want to sand it as little as possible though. Try to do it evenly around the entire thing, I usually do a pass around the piston, wipe it off, test it in the cylinder and then continue to sand it until it slides freely. If I recall correctly, I had to use a different cylinder than the one I cast the piston in...but I just cut another piece of tubing from the same stock I used previously.

[kode1303]

Nice machine! ... But why do I have strange urge to buy household suerface wipes? :-|

[IronGoober]

Admiring my clever product placement? Sadly, I did not get paid...

[tikifish28]

does the big cilinder have to be touching the cilinder and if not how far away does it have to be from it?

[IronGoober]

Yes, the displacer chamber (or divider between the two metal disks) is clear plastic from a small container that I cut down to size with a Dremel tool. See the previous comment from "anthacdc" to see how I made the piston. The displacer (the white thing, which is just styrofoam) needs to be very close to the wall, 1mm or so. It will still run if it is a larger gap, but it will not run as good. You want to shuttle as much air back and forth as possible.

[tikifish28]

Ok i have a few questions, first between the two metal disks on the bottom, what is that divider, clear plastic? and how did you make the JB weld pistion??

[nher33]

AWESOME!!

[anthacdc]

hello,

what did you use to make the expansion piston(the white piston). and did you make the compression piston from jb welf am i correct?

if so didnt the jb weld stick to the mold?

thanks for all the help.

[IronGoober]

The displacer piston is just styrofoam from some packaging. I sprayed the inside of the power piston cylinder with cooking oil before dripping the JB weld into the cylinder. Then I just let it dry and popped it out with a hammer, punch and some pliers.

[nitrorcman108]

i have always wanted to build one of these out of cans but i could never get them to work. could i have your mini one to use as a reference?

[IronGoober]

This one I gave to a good friend as a gift...after filming it of course...

[nitrorcman108]

k thnx

[adisharr]

Hey great project man :)

[mfdiogo]

great video! I am looking for cheap and alternative sources of energy self-generation for domestic use. I believe that studies like yours are very important for that.

[comwarrior69]

nice... i like it...

[IronGoober]

The displacer chamber was just a small container that I bought at REI Sporting Goods and cut it apart with a Dremel tool. Or did you mean the top and bottom plates? They are just aluminum sheet...

The displacer chamber is about 3/32"inch thick, or about 2.5mm.

[henloy]

dam dat shit is tight

[theADDkids]

become a member of instructables! I really want to see this project!

[impazzitoinvolo]

Very Nice and efficient!

COngratulations!

[Huggy13ear]

holy crap that thing hauls

[fuzzymonkey777]

That's a fast little engine. Did you have to sand the JB Weld? Those kind of brass tubes aren't perfectly cylindrical, did you do anything to the brass tube that hold's the JB piston?

[IronGoober]

Yes, I did sand the piston, but as little as possible. I sanded it around once, and then took the piston and spun it in the cylinder until brass rubbed off on the high spots. Then I just sanded the high spots until it would drop right through the cylinder, but would hold air well when the cylinder was plugged. The brass tube is close enough to perfectly cylindrical that it works well. I did have to have the right rotation of the piston and cylinder in order to get the best fit.

[Chaplynskypictures]

What di you use for the piston(the main one).I can't choose the material??? :|

[IronGoober]

I used JB weld epoxy. I dripped it into the brass cylinder when it hadn't hardened yet and then waited for it to harden. Once it had, I knocked it out with a small punch and sanded it lightly. It works great, and is a relatively cheap way to do it.

[Chaplynskypictures]

Thanks Helped alot)))

[simi112]

Very good job!Congratulate! How do you make work  piston?