Motor torque magnetic resistance on MAVRIC AIR 2

[Commodore Mavic]

Probably answering my own question here but...

Is there supposed to be different resistance on the motors when not powered. I have read some other posts and it just seems to be manufacture tolerances is this correct.

It is the motor with the MAVRIC AIR 2 logo on the arm that has slightly more resistance when turning with finger. It still flys normal with no diagnostic errors.

 

[old man mavic]

i will probably be laughed at,but i have a theory that there is some residual magnetic field that is left in the windings when the motor stops ,which causes the resistance felt between the permanent magnets on the outer spinning part of the motor,i am sure that @sar104 will put me right ,as he is much more knowledgeable than me on such things

 

[sar104]

i will probably be laughed at,but i have a theory that there is some residual magnetic field that is left in the windings when the motor stops ,which causes the resistance felt between the permanent magnets on the outer spinning part of the motor,i am sure that @sar104 will put me right ,as he is much more knowledgeable than me on such things

I'll do my best. The windings are copper and so the magnetic field that they produce is from the flowing current - not magnetic dipole alignment in the metal. When the current isn't flowing the field vanishes. I think that the notchy feeling when you spin a brushless motor is due to the interaction of the spinning permanent magnets with the stator core.

 

[old man mavic]

I'll do my best. The windings are copper and so the magnetic field that they produce is from the flowing current - not magnetic dipole alignment in the metal. When the current isn't flowing the field vanishes. I think that the notchy feeling when you spin a brushless motor is due to the interaction of the spinning permanent magnets with the stator core.

thanks for your reply it was just an idea i had to explain it ,its funny though if i spin my motors slowly especially on my MPP with the props removed the resistance from the magnets and the core does seem to be different between motors,i would have thought that they would all be the same, maybe it is the air gap that varies during manufacture ,between the two components

 

[Starz]

Or maybe those crusty old fingers!
No fun getting old, except for the granddaughters!