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Simple Homopolar Electric Motor

video Simple Homopolar Electric Motor

Here's a video I made a while back. It has had some pretty amazing popularity around the web and I thought I might as well include it here. It is not unique, but hopefully the video is helpful to some of you.

46 comments

1-40 of 46

Nov 10, 2009. 3:39 AMCrashMGD says:

There is no explination as to how this works. It is actually a small phenomenon

Mar 9, 2012. 2:57 PMkhaz says:

It is a phenomenon, though not so small in my opinion. Any way the motor works just fine and fancy it is.
Phenomena of this kind have been described by physicists and electrical engineers for some decades. One wikipedia entry could be Force on a current-carrying wire . The formula which describes the force in case of a straight, stationary wire shows that the force is proportional, among other factors, to the current. In this case the current is significant, since it is a short-circuit current. This example of electrical engine is cute and fancy. Watching the video was great fun.
In the pictures below I tried to draw the model and the circuit.

Mar 9, 2012. 3:21 AMconiosis11 says:

.....can you please give me a website that I can Buy a Magnets

Mar 9, 2012. 8:54 AMshoemaker (author) says:

Ebay.com - neodymium magnets round

Jan 20, 2011. 7:14 PMpopscott3 says:

Can you use any kind of wire that is atracted to magnets?

Jan 21, 2011. 9:33 AMshoemaker (author) says:

No, use copper wire (not ferromagnetic) and a neodynium magnet with the silver metallic coating. The magnet has to be conductive and the wire has to NOT be attracted to a magnet.

Jun 16, 2011. 3:21 AMluigithehoverboardinventor says:

is it okay if the neodyium magnet is small?

Jun 16, 2011. 9:16 AMshoemaker (author) says:

Yes, in fact the video has a link to another version of teh motor that uses a very small magnet. I guess there is some limit to how small the magnet can be.

Feb 25, 2010. 12:47 PMwalkingagh says:

So I am about 90% sure this is what is going on. What you have is a current that is flowing. Any flowing electric current produces a magnetic field and the the same way a moving magnetic field produces a current.

What is happening is that because the wire is coiled in a spiral, it is creating a magnetic field that is at an angle to field of the magnetic field of the magnet. This creates a force which spins the wire. Because turning the wire turns the magnetic field, it keeps on turning.

You could test this by 1) Reversing the turns to see if it reverses. or 2 Reversing the magnet which should also reverse it. If it's just "running away" then the magnet direction shouldn't matter.

Feb 25, 2010. 12:55 PMwalkingagh says:

Just thought about it one more time, and reversing the coil won't work, but reversing the current, or the magnet will.

May 24, 2011. 11:07 PMjkmerlin says:

Except the copper doesn't have to be spiraled to work...

Nov 23, 2010. 11:37 AMspacecappa says:

does it hav to be copper wire?

Feb 9, 2010. 4:53 PMUmbraa says:

would it spin because of the way the electricity is flowing?

Apr 8, 2008. 8:53 AMGorillazMiko says:

Awesome! I want to try this out, so maybe I will. ;-)

Aug 6, 2009. 5:04 PMOBar says:

The coconuts?

Jul 19, 2009. 3:32 AMpocketsnzl says:

its cos your attaching the wire to a negatively charged magnet and the positive terminal of the battery so your charging the wire negatively and its creating a circuit and the wire is trying not to touch the negatively charged shell if the battery so all it can do is spin around haaaaaaaa i like physics

Aug 4, 2009. 10:30 PMtaylor179 says:

lolololololololololololololololololololololololol rofl lmao i do believe you just powned him :) (no offence shoemaker)

Mar 3, 2009. 10:10 AMtimb12957 says:

I can see that this could work. However things like the balance of the wire coil, how centered the battery is on the magnet, the amount of contact by the bottom of the wire, are all very critical. I made several attempts with different configurations. It would start to work, but stop before a full revolution. And be careful! Small gauge wire left in contact with the battery for just a little while becomes very HOT!

Aug 19, 2008. 6:59 PMwolf555hound says:

.... i just tried to connect the wire and the magnet with the tip, i got shocked. word to everyone, im an idiot, and dont connect the wire to magnet while adjusting the hook, lol

Mar 3, 2009. 10:05 AMtimb12957 says:

No, you might have thought you got shocked. The sensation you received was you got burned. If you use a small gauge wire, it gets very hot when connected to the battery terminals. I got the same sensation and realized what it was.

Jan 27, 2009. 4:08 PMeggman says:

i want to know just how the hell you got shocked with 1.5V

Jan 7, 2009. 11:19 PMlolgirl says:

i tried this thing but it dose not won't to work!!!!!!!!!!!!!!!

Dec 3, 2008. 4:32 PMBridel568 says:

I got this copper wire will that work? with or with out the insulation

Apr 22, 2008. 7:17 PMacecraze says:

hi! i just want to know if any type of magnet would work/ give the same results, otherwise, where can i get one like the one there? please answer!

Apr 23, 2008. 9:02 PMshoemaker (author) says:

The magnet has to be electrically conductive. I suppose you could use a non-conductive magnet with a conductive washer or something sandwiched between it and the battery. You need a complete circuit from positive to negative poles of the battery. The batteries that I used are neodynium or rare earth magnets. I borrowed mine from work, but they are readily available on ebay or many other places over the net and at craft stores. These magnets are very strong and I'm sure that helps the motor work well/better, so other magnets might not work as well.