Re: G201s and BIG step motors

Hello Mariss,

I am somewhat confused about G201s with really BIG step motors
(double stack 42 and bigger I have double stack 42 steppers
from API Controls Div, two winding bipolar, M422-12S, 3.6v 6.1 Amp.
The 6.1 amp is lower than the 7A max capacity of the G201.

Looking at the Gecko site, rule of thumb for overvoltage is about 25X
maximum. This puts me at about 90 volts, slightly over the 80v for
the G201. Do I really need to run these from 120++ volts, is the 25X
value for size 34 motors and not 42 size?? I have noticed from the
site links that double stack 42 steppers have torques of ~ 2000-2500
in-oz's. My steppers are rated at 1100 in-oz's. Are these M422-12S
just older designs, of somewhat less power than current state of the
art? Will I get nearly full performance from the API M422-12S
steppers when run by G201's @ 80v and 6.1A?

Thanks , Stan K

> Hi,
>
> Anyone using G201s with really BIG step motors (double stack 42 and
> bigger) may need a modification to their Geckodrives to get maximum
> performance from these motors.
>
> It involves mid-band stability for these motors and requires

changing

> the value of a single resistor inside the G201. We will make this
> change free of charge and return the drive within 24 hours.
>
> This change will make really SMALL motors work worse and have
> absolutely no effect on all other motors.
>
> This modification will be called "-42", so ask for a G201-42 if the
> application will be a really BIG motor.
>
> Sorry for any inconvenience this may have caused.
>
> Mariss