Re: [CAD_CAM_EDM_DRO] EMC Fix Ideas

Ozzie@... wrote:

> A while back I posted my problems with getting my CNC setup to work,
> under Lost steps.
>
> Many thought that my problem was with electrical noise, that the
> wiring of my Camtronics driver was at fault, etc.

<snip>

> But the results are the same; CNCPRO will execute twenty moves at
> virtually any speed, and return to it's start point within a half
> thou
> on a cheap dial indicator. EMC will not do two moves within .005".

There is one other thing that was discussed a while ago. I don't know
if Camtronics
drivers were involved or not. It was that the direction signal was
changing at about
the same time as the step pulse was generated. The person who figured
it out
made a small change to the code (or Fred Proctor did it for him) so that
any
direction change was put out BEFORE the step pulse, by a few
micro-seconds.
This fixed a bunch of odd, non-reproducible problems like you are
experiencing.
I don't know if this change was made a permanent part of EMC or not.
You might look in the change history of steppermod.c and freqmod.c and
see
if there is a listing of changes that sound like what I describe above.

Jon