RE: EMC setup

["Tim Goldstein" <timg-at-ktmarketing.com>]

Ian,

A P100 does not have enough horsepower to drive steppers very well. Are you
using Freqmod or Steppermod? The problem is worse with Freqmod, but
Steppermod has more of a problem with irregular timing. Either way you need
to adjust the parameters to get the pulse frequency increased (shorter
period or cycle_time depending).

With a P100 and steppers my guess is the best you will get is relatively
slow movement without getting stalling on the motors.

Tim
[Denver, CO]

> Hi,
>
> I'm sure I should know this, but can someone enlighten me on
> setting up EMC
> to run steppers please?
>
> The difficulty I'm having is in controlling the speed of the motors. I
> assume that INPUT_SCALE is the parameter to change to set the
> motor rotation
> to match the gearing/screw set up so that an input of 1 inch moves the
> machine 1 inch. However, this also seems to affect the speed of the motors
> and, outside a certain band of values in this parameter, a couple of the
> motors I have get very rough in operation and slow right down. Needless to
> say, this lumpiness is in the band of values I need to get the proper
> translation.
> Is there another setting I should be changing to improve the motors'
> performance?
>
> I'm using steppermod on a RH5.2 install with the March 200
> release of EMC (I
> don't seem to be able to get freqmod working yet on this release)
> on a P100
> machine which seems to work OK otherwise - i.e. it seemed to operate a
> previous experimental setup of EMC and motors.
>
> Ian
> --
> Ian W. Wright
> Sheffield  UK
> www.iw63.freeserve.co.uk
>