Re: [CAD_CAM_EDM_DRO] Re: Baldor spindle motor as servo motor 4th axis

Bob Muse wrote:

>The only thing that I can think of is that a true servo motor is designed to
>produce it's rated continuous torque at any rpm from max all the way down to
>stall without overheating whereas your baldor probably needs to be turning
>at some minimum speed for the fan to move enough air for cooling. If this
>were to turn out to be a problem you could always add a seperately powered
>fan.
>
>

There is another difference - servos are designed to have very low rotor
inertia, so the speed and direction can be changed rapidly. "Normal" DC
motors are made with high inertia, because that smooths out the motion
for a single direction. (it's the difference between a CNC and an
escalator - the escalator rarely changes direction or speed, but you
want smooth uni-directional motion even with changing load)

If you want more info on the subject, search through the archives for
the (long :) ) discussions about using treadmill motors as servos.

- Steve