On Thu, 11 Jun 2009 23:47:04 -0400, Wes wrote:

Ned Simmons wrote:

Motors that are marketed as servos also usually have lower inertia
than typical motors and magnet materials that are more resistant to
demagnetization under high peak currents. Both important features for
high acceleration, but often overkill in modest applications.

Very high currents from overloads can kill those magnets. I've had to replace motors for
that reason.

Yup, there's a reason for the current limit on amps and drives. A
run-of-the-mill brushed DC motor might tolerate a 2:1 or 3:1 peak over
nameplate current before demag. Some high performance motors with
exotic magnet materials are OK with 7:1 peaks.

--
Ned Simmons