A motor with only a battery, wire, and magnets.

Step 1: What to Get...

The things that are needed:

C or D cell battery(almost any store has it)
26-20 guage solid wire(from almost any hardware store)
Magnets-really strong kind(from ORVAC or any store like that)
Compass-To find north of magnets(from...)

Step 2: The Wire...

Bend the wire so that its in the shape of a square... like so...

Step 3: The Magnets...

Put the magnets so that there all facing north. You can find north with the compass. Put it in order in the picture as shown.
The big magnets are on the bottom and the top of the magnets are facing up and the polarity is facing north. The wider magnet on the top is to hold the wire in place and have better connectivity.

Step 4: Putting It All Together.

Put the wire(hole side down) around the magnets to let it spin freely with the top touching the neg. side of the battery.

Step 5: Collabrating Time...

Make sure that the wire sits on a dipple of the top of the battery and also make sure that the bottom of the wire is touching but can still spin. The wire has to spin freely with no or little friction to achieve maximun results. Callabrate it till it can spin and keep on spinning. Notice that the battery is ballancing on the magnets. The battery never moves nor the magnets, the wire will move rapidly by itself.

Step 6: Problems and Difficulties

Make sure that the battery is fresh, the magnets are north facing up to the battery, the wire can spin freely while touching the magnets and the neg(wire connecting pos. to neg.)
I attached a video of the motor.
Hope it works... Its my first instructables...

Step 7: How It Works.

The magnets are constantly attracting and pushing the wires which are magnetized becuase of the eletricity running through it, thus makes the wire turn...

You can put it on the side and if its strong enough... It can roll forward or backwards, it depends.
For more information visit:
http://sci-toys.com/scitoys/scitoys/electro/homopolar/homopolar.html

For more projest please visit:
http://www.scitoys.com

I hope you have fun.