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Neodymium Magnets? Answered

I have a motor out of an waxer/buffer and I was wondering what improvements neodymium magnets would be.  I have a couple plans for this motor, the first being for a temporary ball mill, and the second for a generator.  I am pretty sure the neodymium would be good for a generator, but what about a motor.  I am also wondering what magnets to get.  Should the north pole be the outside, south pole be the outside, should it be magnetized thru circumference, magnetized through thickness, or south on one side and north on the other.

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frollardBest Answer (author)2012-05-27

Whatever it is it has to match the geometry of the original magnets...or the motor won't turn without a reworking of the windings/commutator.

If it is an AC motor, it probably has windings for both the rotor and the stator, and no permanent magnets - so adding magnets would do nothing (except hinder).

Lastly, in PM motors, neodymium is ideal because of the relatively large magnetic flux per mass of magnet...

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jj.inc (author)frollard2012-05-27

It is a brushed DC motor with a simple rectifier on it to turn 120v ac to 120v dc. Will the speed increase with neodymium, or just the power and efficiency.

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frollard (author)steveastrouk2012-05-28

I'm rather blown away that it would use a PM motor...

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steveastrouk (author)frollard2012-05-28

If "blown away" = "absolutely amazed", then I'm with you......

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frollard (author)steveastrouk2012-05-28

shocked, dismayed, confused, confounded, critical...yes. :)

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jj.inc (author)steveastrouk2012-05-28

Yes it is a PM, I thought the same thing when I first opened it up.

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steveastrouk (author)2012-05-28

In general.

More field = more torque, less speed.

Magenetisation direction whatever the motor design needs to create a radial flux between the rotor and the stator.

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