Sam Goldwasser wrote:
>
> > Tim Wescott writes:
> >
> >>Sam Goldwasser wrote:
> >>
> >>
> >>>Another thing to note but which probably doesn't apply here is that if
> >>>some PM motors are disassembled without a "keeper" for the PM magnets,
> >>>it will become partially demagnetized. This isn't a problem with the
> >>>cheap PM motors you are probably using but may be with high quality
> >>>steppers or servo motors.
> >>>--- sam | Sci.Electronics.Repair FAQ Home Page:
> >
> >>I know that's an issue with AlNiCo magnets, and I know it's _not_ an
> >>issue with Neodymium-Boron-Iron (temperature will kill those suckers,
> >>but not demagnetization). Is it a problem with Samarium Cobalt or any
> >>other modern high-performance magnet material?
> > The motors I'm referring to almost certainly used magnets more high
> > tech than AlNiCo but I don't know what it was. There must be some
> > info on PM motor maintenance from motor manufacturers on the Web that
> > would shed some light on this.
>
> I was just curious if you knew.
>
> Certainly a motor manufacturer could tell you this if they encouraged
> maintenance on their motors. Many really small motors aren't designed
> to be disassembled, however. Even the $150 precision motors from the
> Swiss -- Escap and Maxon -- are pressed together and don't come apart
> without fatally changing their characteristics.
I'm guessing the motors the original poster was referring to are the $1.50 variety which probably use ceramic ferrite magnets and really don't suffer from this problem.
--- sam | Sci.Electronics.Repair FAQ Home Page:
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