Motor rotation

[SkyCobra]

I have a double stator 9 tooth motor with a 12 magnet 12 pole NSNS.. can. This configuration runs fine. I remove the can and place it with a 12 magnet 6 pole NNSS.... The motor spins in the opposite direction. I believe I read that a 9 tooth stator can be wound in ABCABC... for both 12 and 6 pole cans. Why the two directions ?

[LBMiller5]

The edge of the wider magnet is closer to an opposite pole than it was before. Just swap any 2 wires between the motor and the speed controller and the motor will run the other way.

[paulvi]

I have a double stator 9 tooth motor with a 12 magnet 12 pole NSNS.. can. This configuration runs fine. I remove the can and place it with a 12 magnet 6 pole NNSS.... The motor spins in the opposite direction. I believe I read that a 9 tooth stator can be wound in ABCABC... for both 12 and 6 pole cans. Why the two directions ?

What would the benifit be of going 6 magnets poles VS 12 magnets poles?

[Q]

Rotation speed

[RonD]

To elaborate a little more, everytime the ESC cycles through the 3 wires the motor advance by one magnetic pair (2 magnet positions). So with 6 magnets (3 pairs) it takes 3 cycles to rotate the motor one full turn. With 12 magnets (6 pairs) it takes 6 cycles to rotate the motor one full turn. Another way of thinking of it is the 3 pairs gives a pseudo 3:1 gear ratio and the 6 pairs gives a 6:1 gear ratio. The 3:1 gear ratio gives approximately twice the RPM but 1/2 the torque. The total power is about the same, but the torque and speed change.

[paulvi]

ok so with that said if i were to set up a stock motor config of 12 poles

NSNSNSNSNSNS

would this be better if I am shoting for RPM smaller prop on a high wing loaded gas conversion

NNSSNNSSNNSS double wide mags or should there be gaps in the mags

may be rethinking how I have my 15mm stator and can maged..

[Q]

IMHO I think it would be better to go for an 8 magnet version. A 6 magnet motor will be less efficient. Of course you will have to rewind the stator.

Any way, it's better to keep the gap between the magnets as small as possible.

[SkyCobra]

The edge of the wider magnet is closer to an opposite pole than it was before. Just swap any 2 wires between the motor and the speed controller and the motor will run the other way.


Thanks LB, since I'm using 5mm wide mags, does this mean somwhere between 5 and 10mm there will be a neutral point .ie where the motor could startup in either direction ? Oh no, more testing !!!

By the way, the can looks just like the picture you have, 25mm stators "double stack". With a 9.5 GWS HD, the 12 mag pole has 7 oz thrust, the 6 pole mag has 12+ oz thrust. The amps are only about 3+ , so this motor should be able to throw a much larger prop just to get it to start working hard. If I could only get the can lighter.

[RonD]

Thanks LB, since I'm using 5mm wide mags, does this mean somwhere between 5 and 10mm there will be a neutral point .ie where the motor could startup in either direction ? Oh no, more testing !!!


No if the motor is at a neutral point when you start up it may stutter back and forth momentarily. This motion will move it from the neutral point and it will then run in the right direction.