Introduction: These Hearts Are on Fire

The homopolar motor is the simplest motor in the world. It's made of a battery, magnet, and a piece of wire.

In this case, I use a AA size NiMH battery, a 1/2 inch x 1 inch neodymium supermagnet, and some bare 10 ga. copper wire. I bent the wire around a D-cell battery to form the heart shape.

This video shows several variations of this motor, using two different wire-form heart shapes as the basis. In the end the two hearts unite to become one.

Background music "This Heart's On Fire", courtesy of alternative band Wolf Parade.
This video dedicated to all Hearts on fire everywhere!

You can order neodymium super-magnets from K&J Magnetics


BryanB7 (author)2016-01-10

This was so simple to make .Thank you the ladys love them.

scrambles00 (author)2014-06-03

Will this kind of gage wire work?: It says AWG 10 but I realized that it's different when I got home already.

scrambles00 (author)2014-06-03

Will this kind of gage wire work?: It says AWG 10 but I realized that it's different when I got home already.

porcupinemamma (author)2009-08-25

I am a techno-phobe, but your project seems possible for a person without any experience (me) I love your instructables. I don't have the skill or understanding how to make make them, but I think you have neat ideas!

Thanks for the complimentary comment! The Hearts homopolar motors are a great entry point for non-technical folks to play with the forces of magnetism and electricity. The Hearts are relatively easy to make, especially in a wire gage that is thinner than the heavy 10 gage that I used. The Tesla CD Turbines I make are built are simple...but not necessarily easy. There are plenty of little details that make the difference, and sometimes even I still make a turbine that simply doesn't work. However, each effort to make something stretches one's abilities, tolerance levels, knowledge and most important, one's fun experiences in this world!

chi chi chippy (author)2009-07-15

ive tried to make some of these motors but none of them work i need to now wat gauge of wire u used and maby i need a bigger magnet idk can u help?

Sure, I can help! Are you using a neodymium magnet, preferably at least 1/2 inch x 1/2 inch size? I used 10 gage household wiring copper wire, but any size up to 20 gage will work. Thin wire can heat up your fingers! The wire must be bare where it contacts the battery and the magnet. (some craft wire have a coating that has to be removed with sandpaper) The Heart with two legs that touch the magnet has to be adjusted so the legs have a gap to the magnet. If they are both touching at once, there will be too much friction and the motor will not work. The battery must be powerful. I prefer the rechargeable Duracell 2650 MaH. A regular Duracell will work too, but it won't last very long. Some batteries are not very magnetic and won't work. Try these things, and let me know how it goes.

SKYNET 2.0 (author)2009-07-04

About how long do the spin for? Have you ever thought of using one of these as a joule-thief for rechargeable/standard batteries?

mrfixitrick (author)SKYNET 2.02009-07-05

The heart-shape homopolar motor will usually go for about 3-5 minutes, sometimes up to ten or fifteen minutes. That's with a heavy-duty 2650 MAh NiMH Duracell rechargeable. Doesn't a Joule-Thief collect the residual power in old batteries? How might this motor work that way?

SKYNET 2.0 (author)mrfixitrick2009-07-09

I always thought that they simply deplete the old batteries completely before you dispose of the said batteries, I could be wrong. Although you have given me a good idea if it hasn't been done yet. You could make a rig to take nearly-dead batteries and use their "dying-breaths" to charge a single/multiple rechargeable battery(s).

Pyro Fiend (author)2009-05-25


nerfer192 (author)2008-01-28

dammit....i cant seem to make this and i just shorted a battery and now im scared to keep on trying to build one.

mrfixitrick (author)nerfer1922008-01-28

OK, don't panic...let's made a heart shape? with open or closed bottom? what size magnet? It is neodymium, right? what size battery? How did it short? If you can answer some of these questions, I can help. These motors are simple, not easy. They seem to have good days and bad days, hehe.

nerfer192 (author)mrfixitrick2008-01-28

i did not make a heart shape, i tried to make the 5 speed without the coins, seeing as im not in canida. the size magnets are about 3mm tall, 12mm wide (not sre, thats a guess. the magnets used are "black hole" earth magnets (which im pretty sure is neodimium, theyre silver, not black like a refrigirator magnet.) the size battery was aa and i also tried aaa. the way it shorted was an attempt at someone elses instructables on this and the wire touched the top while the wire on the bottom touched the magnets the magnets touched the batter and wahlah, a super heated wire IN MY HANDS i got freaked out becuse one time i tried to biuld a rc thing out of an old rc boat and i heard a woosh and saw a orange glow under my project and a puff of smoke, and proceded to say "mummy im scared" (that was like a couple years ago)

mrfixitrick (author)nerfer1922008-01-28

Ok I get it now...I thought you were building the heart from the coathanger wire, which won't work. If you use the coathanger wire as a support, it should work similar to the five-speed video. You must be sure of a bare connection to the coathanger; there is usually varnish or paint to scrape and sand off. And you must use a copper wire to the magnet. For the motor you tried in your hand, use a bigger copper wire so it won't heat up so much. Keep at it...yes it can get a little dangerous, but (as in life!), if you pay close attention, chances are you won't be hurt.

nerfer192 (author)mrfixitrick2008-01-29

thanks but how do i make the simple five speed without that shifter and the coins? i dont have canadian coins or copper wire.

mrfixitrick (author)nerfer1922008-01-29
Here's another of my homopolar movies, called "Homopolar Motor Variation"

I use a piece of welding rod for the stand. Welding rod is like coathanger wire, but it has a copper coating.

You will need a short piece of copper wire to attach to the hanger support. You can use coathanger, but the paint or varnish must be sanded off where the copper wire makes contact , and the coathanger filed down to a smooth surface where the battery hangs on.

You can try washers instead of coins.
Good luck!
Pyro Fiend (author)mrfixitrick2009-05-25

HOLY F************K!!!!!!!!!!!!! IS THAT NEODYMIUM???!!!! THAT MAGNET IS REALLY STRONG!!!!!!!!!!!!!!!!!!!!!!!

nerfer192 (author)mrfixitrick2008-01-29

okay, but how does the wire bottom wire go near the magnet without attracting to it and stopping the motor?

mrfixitrick (author)nerfer1922008-01-29

The bottom wire is copper, and should not attract the magnet. It is wrapped around the sanded-off coathanger for good contact. It needs to lightly touch the magnet to complete the connection and make it turn.

nerfer192 (author)mrfixitrick2008-01-29

i guess copper doesnt attract to magnets.

mrfixitrick (author)nerfer1922008-01-29

That's correct generally...yet an electric field from a copper wire can be attracted or repelled by a magnetic field, as in the Hearts video, above. This is the basis for most electric motors. Also, a thick copper or aluminum pipe will slow down a magnet dropped through it, due to induced eddy currents. And even a US copper penny gets attracted to a moving magnetic field, by the same effect. However, for your five-speed/one-speed homopolar motor, the magnet contact must be copper wire, and not copper-coated steel. I tried to make it work with steel wire, but the magnet attracts it and things come to an abrupt stop.

nerfer192 (author)mrfixitrick2008-01-29

i see. and they will short out too

mrfixitrick (author)nerfer1922008-01-29

Yes, and the sparks can fly and things can get hot, so use safety glasses for unknown experiments. And develop calluses on your fingers so the hot wire doesn't hurt so much! (Kidding about calluses...mostly ;)

n0ukf (author)mrfixitrick2008-03-11

And in case you end up with red hot wires, do this on a piece of ceramic, glass or other material that won't burn or melt if it comes in contact with shorted wires.

nerfer192 (author)nerfer1922008-01-28

i think i might be using the wrong wire too, i used an old coat hanger. it has paint on it, which might affect the way it works, and plus its not copper.

mrfixitrick (author)nerfer1922008-01-28

You got it...the coathanger wire won't work. You need some copper wire, such as solid 10 or 12 gage, from a piece of house wiring. Try that and let me know.

nerfer192 (author)mrfixitrick2008-01-29

sorry, ill have to make a trip to the hardware store because i dont have any right now. soon.

Sputny (author)2009-05-19

Is the heart shape the best shape for quality and can you use a D cell battery

mrfixitrick (author)Sputny2009-05-19

The heart shape is the simplest to make and balance. You can also make a shape as shown in this movie from American Sterling Engine, who has kits available with 3 magnets and wire at this link.

You can use a D-cell but the heart wire must still contact the magnet at the bottom.

orv_16 (author)2008-11-09

got mine to go not sure how long it lasted on a battery i left it and i came back it was hot and the wrapper was peeling :P what is the worste that could happen? once again great project :)

mrfixitrick (author)orv_162008-11-09

The worst that can happen, you don't want to know about. (i.e. house burns down, etc.) General rule is never leave a homopolar motor setup unattended. The wire and battery can get very hot. Some batteries can explode! I usually only run for a minute or two, because abusing the battery like that will kill it fast. If a battery or wire gets hot, it's time to give it a break and allow it to cool down. Watch the fingers! hothothot hehe

orv_16 (author)mrfixitrick2008-11-09

i'll keep that in mind :P thanks alot

mrfixitrick (author)orv_162008-11-09

Happy motoring!

By the way, there are still a few hours left for folks to vote for my instructable
in the Party Like It's 1929 Contest at the top of the Instructable.

A good rating for that instructable would be highly appreciated, too.

Thanks a lot to those who help!

orv_16 (author)2008-11-09

hardest part for me is making the heart nice :P

mrfixitrick (author)orv_162008-11-09

That's true! Especially with 10 gage copper wire...very hard on the thumbs! 12 gage or 14 gaga would be easier. After bending the wire in half first, I used a piece of 1 inch pipe in a vise, to help make the main bends of the heart shape. A D-cell battery is about the right shape to wrap around, too. I'm sure you will agree that it's worth the effort in the end!

orv_16 (author)mrfixitrick2008-11-09

i used the flashlight i got my magnet from i bought two for 10 at walmart along with some AA batts and now im going to see how long it will last on one :) thank you for the first instructable i did, influenced by its mesmorizing spins and simplicity

mrfixitrick (author)orv_162008-11-09

Right on, orv_16!

The shake flashlight magnet trick works good in a pinch. And you can likely find a use for the LED's and the battery in it as well.

To order bigger quantities or special sizes go to my cdturbine,com website and order from the K&J Magnetics banner.

narunijja (author)2008-10-15

does the battery need to be live?

mrfixitrick (author)narunijja2008-10-15

Yes, a fully charged AA battery is best. Preferably a NiMH rechargeable Duracell 2650 milliamp-hour(mah), which are the most powerful commonly available.

Kaiven (author)2008-10-07

this is soo cool! I'm gonna try it right now!

Kaiven (author)Kaiven2008-10-07

I did it, but IDK how you got yours to spin so fast xD

mrfixitrick (author)Kaiven2008-10-07

Speed fast do you want to go? (old hot-rod saying, hehe...) The speed of the homopolar motor is directly related to the voltage and to the size of the magnet. I used a 1inch x 1/2 inch N52 Neodymium, which is pretty big. Make sure the battery is well-charged and has adequate capacity...I prefer Duracell AA rechargeables with the 2650 maH rating. Use heavy gage wire...10 or 12 gage. Be sure there is a small gap between the wire and where it rubs on the magnet. Dimple the positive post of the battery to keep the heart on better. Tweak, tweak, tweak. It took a long time to get everything just right!

Kaiven (author)mrfixitrick2008-10-08

Ok, My wire is definetly like half the size of yours, I use 6 neodynium magnets that, together, look the about the size of yours. I use cheap AA batteries. Oh, and I have a dimple in my battery too.

mrfixitrick (author)Kaiven2008-10-08

Ya gotta upgrade to run with the fast crowd! hehe...have fun!

Kaiven (author)mrfixitrick2008-10-08

Thanks! And I've noticed that you have a nice black hooded... jacket or robe? Did you buy it or make it?

mrfixitrick (author)Kaiven2008-10-08

That is a thin black see-through hood and a kind of a cotton smock with a belt, you might say. Kind of spooky and great for Halloween, but I used to be part of the North American Bunraku Puppet Theatre. Three people operate one life-sized puppet, usually against a black background. Along with black tights, slippers, socks and black gloves, we called this outfit our "blacks". We played at the California State 1985 !!

Kaiven (author)mrfixitrick2008-10-09

Wow. So you are at least... nvm lol my brain is dead... Im in math class :D

mel81 (author)2008-07-20

i've been using fridge magnets and they don't seem to work, what magnets are you using?

mrfixitrick (author)mel812008-07-20

You must use neodymium magnets, which are magnetically strong and electrically conducting. Some fridge magnets are neodymium, but it would have to be a larger one to work well.

A good source for neodymium supermagnets is a shake-to-charge flashlight, if you can get one cheap at the dollar store or Wal-Mart.

Otherwise, K&D Magnetics is my favorite place to order magnets from. Just click on the K&D banner at my website to connect to them.

About This Instructable




Bio: I am re-inventing myself as an inventor, after too many years as a mechanic! I enjoy learning from Tesla disc Turbines, magnetic motors, and Crystal ... More »
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