Re: Stepper Question (Newby)

What is the current and voltage rating on your stepper motors?
What voltage is your driver ?

Need to know this to help you.

Frank

--- In CAD_CAM_EDM_DRO@y..., ccs@m... wrote:
>
> > He everyone. I have finally got my Taig Mill hooked up using the
> > Stepperworld FET-3 and 150oz stepper motors. Everything seems to
move
> > correctly however I can very easily hold the other end of the
motor
> > shaft to stop movement. The motor seems to hum as if something
inside
> > is moving but the shaft is not.
> >
> > Anyone have a clue as to whats happening. I don't think that I
should
> > be able to stop a 150oz stepper motor that easily.
>
> The humming you are hearing is just from coils in the stepper.
There
> is only one moving part, and that is the rotor - I would consider it
> fairly unlikely for that to have come loose from the shaft.
>
> Good stepper drivers regulate current by turning the coil on and off
> extremely rapidly, which does produce some humming. Often this is a
> frequency above what you can hear, however not always. One widely
> popular circuits has a common failure mode where the freqency drops
> quite a bit below what it is designed to be, and torque suffers as
the
> duty cycle is also messed up.
>
> The problem may be far simpler and more fundamental though: many
> (actually most) inexpensive stepper drives are limited to 2 or 3
amps,
> and so cannot supply enough current to run a 150 oz/in motor which
is
> optomized for high speed operation (ie, has a high current low
voltage
> winding).
>
> So, either check your drive setup, and if that fails, spend the
money
> on a good driver that can supply rated current to your motors. Make
> sure your power supply is up to the task, too.
>
> Chris Stratton