Re: [CAD_CAM_EDM_DRO] Re: Plasma table gear reduction

turbulatordude wrote:

>As for motors...... my head is about to explode.....
>
>3,300 max rpm, 750mA no-load, but 960 at 5 amps... amps per oz-in...
>seems motors don't have a very simple rating.
>
>
>

That's because most people who sell these things have no idea how a servo
motor is actually used or specified. No load current rating is almost
TOTALLY meaningless, especially in servo operation, but it is an easy
measurement
to make. RPM drop under load is difficult, but it can be converted to a
more useful
form, if you have some other measurements on the motor. Oz-In/Amp is
one of the
most important measurements, but you'll rarely get that info for a
surplus motor.
It is alos known as Kt. The other important rating is Kv, or Volts/1000
RPM. If you
have either, you can derive the other one. Finally, armature resistance
is useful to
know how long you can apply peak torque.

Jon