RE: Z axis Offsets

["Tim Goldstein" <tgoldste-at-mlh-services.com>]

Been doing a little work with Bridgett using BDI 1.09 with Ray's 8-1-2001
tarball replacing the original BDI EMC. Using steppermod as it is much
easier on the computer with the 10000 steps/in and 120 ipm rapids I am
getting with the Gecko G320 drives. Was trying to use tkemc and kept running
into a problem with not being able to get an offset to reliably work on the
Z axis. Seems to work great on X and Y. I tried doing the offset by both a
G92 and by right mouse clicking on the axis display. Sometimes the offset
will take and the numbers change, but more often than not they don't change.
Even when they do as the offset is frequently ignored when I run in auto
mode. The X and Y axis are not displaying this behavior even though I am
doing exactly the same thing with them.

Switched over to xemc and the problem totally disappeared and the M2 at the
end of the program does not cause the offsets to reset. I did notice in
manual mode that with xemc I can only jog if I set the jog distance to
continuous. If I set it to an increment nothing moves when I press the key.

Much happier now that I am back home again with EMC instead of getting
frustrated with DeskWinNC.

Tim
[Denver, CO]

> -----Original Message-----
>
> Hi Bill,
>
> ----- Original Message -----
> From: "William Scalione" <wscalione-at-nc.rr.com>
> To: "Multiple recipients of list" <emc-at-nist.gov>
> >
> > I think there is a problem with the BDI and ray's tarball
> > concerning axis offsets. I am running freqmod, commanded,
> > relative and world.
>
> There is.
>
> > First thing I do is Home all Axis' and make sure offsets = 0
> > Before running the program I will move Z to -2" and do a
> > right click on the Z axis and set Z = 0
>
> > At program end, the axis offset for Z goes to zero and
> > rerunning the program will send the Z axis to the true zero
> > point, with cutting taking place at true -.2
>
> This is because EMC is canceling the origin offsets when it ends
> with M2 or
> M30 - this is documented.  It writes the offsets to the .var file like
> g92.2.  So after the program ends you have to go to MDI mode and
> enter G92.3
> to restore the offsets.
>
> > The EMC still has those offsets in there somewhere
> > because if after the program runs, I do a Z-2 in MDI
> > mode, the offset still reads 0. Then right click on the
> > Z axis and set it at 0 the offset jumps to -4
>
> This is the stange behavior I'm getting if I ABORT a running program and I
> haven't found a way to recover short of a complete restart and loose
> position.
>
> > Also when starting TkEmc the actual radio button
> > is checked even though Commanded is the default
> > in the INI file.
>
> The variables for the default display mode are in the .ini file but TkEmc
> does not read them - it is hard coded.  I think it's around line 530 in
> TcEmc - just open the file with your handy dandy text editor and change
> "actual" to "commanded".  It's not too hard to find.
>
> Good luck...Joel
>
>
>