> -----Original Message-----
> From: Chris Albertson [mailto:albertson.ch...@gmail.com]
> Sent: August-24-19 12:07 PM
> To: Enhanced Machine Controller (EMC)
> Subject: Re: [Emc-users] MESA 7i92H Saga
>
> On Fri, Aug 23, 2019 at 8:41 PM Gene Heskett <ghesk...@shentel.net>
> wrote:
>
> >
> > I will state that encoders with less than 1000 counts per turn aren't
> > going to be ultimately usefull on a mill where its also stablilizing
> > speed, but even a 240 count I am getting from hall effect sensors
>
>
> There is a trick to making this work. If you have a
> low-resolution encoder, what you do is NOT count the number of "ticks" per
> time interval. But rather measure the number of nanoseconds (not
> microseconds) between each "tick"
>
> Then you control the motor voltage to keep the number of nanoseconds at
> the
> desited value. In practice you sample a fast clock or counter on each
> encoder edge. Gives very accurate results even with poor encoders.
Essentially that's how my ELS can thread with one pulse per revolution. As
long as the spindle drive is stable and doesn't change from turn to turn (and
threading is not a heavy load operation) a 1PPR is more than adequate for nice
threads. Except I'm counting system ticks of 50uS. And it's amazing how well
it actually works but there is a low speed limitation and you can't track the
spindle when turned by hand.
>
>
>
> Chris Albertson
> Redondo Beach, California
>
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