How does one determine the number of poles on a motor?

Count the magnets if you can see them. Or rotate the motor and count the cycles of voltage on one of the windings. Each cycle is two poles.

The ends of the magnets will normally be visible in the gap between the open end of the magnet housing and the base plate. Some motors will have large enough openings on the dome end that the other ends of the magnets can be counted there.

If you have any specs on the motor, the number in front of the "P" in a designation like 9N12P or 12N14P is the pole count.

A magnet actually has two magnetic poles, normally called North and South, with one on each end or side of each magnet, but for this purpose the pair of poles in each magnet is considered to be one pole.

Jack

And just to clarify for completeness sake:

The hammerheads of the stator are NOT called poles, although the stator teeth are electromagnets when the motor is running.

The poles are the magnets.


Christo

Poles are the magnet N/S pairs not the stator teeth.

You peek into the motor and count the number of magnetpoles. Not the number of statorpoles or the number of coils. Controller needs to know number of magnetpoles to determine rpm. A wrong number will not effect ESC operation, only indicated rpm.

Vriendelike groeten Ron

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14magnetpoles/12statorpoles
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14magnetpoles/12statorpoles/6 coils (= LRK winding diagram)