Re: [CAD_CAM_EDM_DRO] emc g92

Tom,

What exactly are the problems you are experiencing? I use the G92 codes
all the time to set my starting point and do not have any problems with
it. I only use the in MDI mode.

As I do not have home switches on the mill and I turn the power to the
pc and xylotex controller off, I have not yet found a way to set the
mill to the exact position as when turned off. I only recently came to
think of it that it is quite normal because the controller will always
start at it's home position (normally every 4 full steps).

I always make sure that the DRO is at 0,0 before turning the systems
off. When starting a work session, I drive the mill up to 0,0 and use
the G92X0Y0 command. I have not seen major problems with it.

What I am missing is a way to set all axis to full zero (without using
the G92). This would allow me to use G92 for real work offsets. But I
guess this is what the G5x commands are for.

Regards,

Geert

>
> I tried Sherline's EMC version and the regular version 2.18, both from
> the Sherline BDI CDs.
>
> I don't think it matters if G92 is MDI or within program. EMC just does
> screwy things whenever you try to use G92. All of the offered solutions
> form the EMC lists, none of which are acceptable to me, avoid the use of
> G92 altogether.
>
> I could not get anybody on the EMC developers list to fix this. They say
> that it works as defined in the spec cuz the spec does not define it.
> How's that for catch 22. Nevertheless, nobody on the EMC list has come
> forward to say that they actually use G92 to do anything. So, if you ask
> me, EMC's interpretation of G92 is somewhere between useless and
> dangerous.
>
> I did all of this in June so some of the details are muddy. Bottom line
> is I cannot use EMC with my Sherline mill until G92, or some other
> Gcode, sets the axis values with no screwy side effects.
>
> Let me know if you have better luck with G92 and I will try again with
> whatever version you are using.
> Tom Hubin
> thubin@...
>