Re: [CAD_CAM_EDM_DRO] EMC and encoders

Wally K wrote:

> If using EMC to run stepper motors and you want to use encoder
> feedback. Are you supposed to match the encoder output count with
> the steps per revolotion. Or is more pulses the merryier. At this
> time i am thinking of using full step with 5mm lead screw, 2 to 1
> drive reduction, and G210 full step to 10 micro step driver. The
> encoder would be a 2 channel complimentry output 250 counts per rev
> and 1000 counts total. I would mount this encoder on the on the
> leadscrew shaft.

I don't think you have to match motor steps (or microsteps) to encoder
counts.
But, an integral ratio would be very helpful in being able to keep the
deadband
small while preventing a lot of hunting.

I assume you mean 250 cycles/rev on the encoder, producing 1000
counts/rev.
a 200 step/rev motor with 2:1 reduction would do 400 full steps for the
encoder's 1000 counts. Maybe a 2.5 : 1 belt reduction would work out
better,
for 500 full steps to the encoder's 1000 . But, it probably will work
fine
as you have laid it out. There will have to be a deadband set up as the

full steps cannot reach all encoder postitions, and even with the
microstepping,
it may not be possible to reliably arrive at every encoder count.

Jon