Re: stepper motors

bobd@... wrote:

>
> There is a danger disassembling stepper motors!
>
> The ones with permanent magnets in the rotor are magnetised in situ within
> the stator or in a 'keeper' and transferred into the stator during
> manufacture. If you remove the rotor from the stator and then return it you
> will find that the motor is less powerful than it was. I did this very
> thing. I extended the rear shaft for a handwheel and that particular motor
> is now weak.

Funny how different people get different results. I also removed rotors
from six Superior Electric SS 150 motors to extend the shafts. I
drilled into the ends of the original shafts and pressed new shafts into
them.

Someone had told me this was not good for the motor so I rigged up a
torque meter and tested the modified motors against unmodified motors.
I could see no difference. They both produced the advertized torque.

John Grant