Re: Stepper motor size question.

Hi Graham,
4 amp motors will work well on a 3.5 amp drive but your maximum current must then be 3.5 amps. Stepper current is directly proportional to holding torque so using a 4 amp motor on 3.5 amps means your maximum torque will be 87.5% of its rated torque. Running steppers below their maximum rating has a couple of advantages, they dont get as hot and they are less likely to be affected by resonance problems.

Regards
Bob Thomas

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "snokket <graham@a...>" <graham@a...> wrote:
> Hello Everyone.
> can someone help please? I have bought the flashcut 3.5amp
> microstepping drive and software. I would like to put larger motors
> onto my mill but am not sure how large I can go. I would like to buy
> the Motors in the uk as I live there so this would cut out the
> postage and import costs. I have seen some size 34 motors at Alzanti
> http://www.alzanti.com but all the size 34motors on the stock list
> are rated 4a/ph.
> can anyone share their experience please, does anyone run the
> flashcut 3.5 amp microstepping drive, If so,would you mind telling me
> which motors are the best to use.
> Thanks in advance.
> Graham.