Today, in the middle of a 4-hour job I've run successfully before, my quill drive retracted to the upper limit.  This happened on a line containing "G51 Z-0.050".  I found I could run the following sequence consistently and repeatedly:

G52 Z0.0
Home Z axis
Manually change Z DRO to +0.75
G0 Z0.0
G52 Z-0.050

When the "G52 Z-0.050" is executed, the Z DRO jumps to some random, large-ish, negative value, like -7.4901.  If I repeat the sequence again, the Z DRO jumps to the previous value -1.2500!  So, the second time I do it, the Z axis will jump to -8.7401, and the time after that to -9.9901.  Now here's the really interesting part:  Exiting and re-starting Mach3 does NOT fix the problem!  Unplugging and re-connecting the SmoothStepper does NOT fix the problem!  It is now stuck in this mode, and I can't get it to behave properly!

Regards,
Ray L.

I am not a programmer but I always thought G52 was associated or used  relative to a work offset, G54~G59 etc?
If you are in G53 mode, why not use one of the G54-59 offsets?
N.

I am not a programmer but I always thought G52 was associated or used  relative to a work offset, G54~G59 etc?
If you are in G53 mode, why not use one of the G54-59 offsets?
N.

G52 applies a temporary offset to the current fixture offset.  It's handy when your datum shifts, to simplify programming.  In this case, I load a piece of raw stock, then face off the top, and use G52 to shift the fixture zero to the new top of the material.  At the end of the program, I remove this offset, and I'm ready to start the next piece.  It normally works just fine, and I've used it a lot, but something has gone wonky in Mach3 making it now misbehave.

Regards,
Ray L.

Ray try loading a backup XML(not the auto version). What I find is that the XML can become corrupt and those values are hidding out there in OZ (machXML) and mach is locked into using them as phantom numbers.

I can send you a routine to run through all the Paramters 1-20,000 and then you can look for those values hidden in the matrix. IF you can find where those values are hiding it may be a clue for brian.

Run the routine and then you have a TXT file of all the values in OZ.

(;-)TP

Terry,

I've already restored an XML from about two weeks ago, which made the problem go away.  I've also sent the XML to both Brian and Greg.  Hopefully one of them will tell me WTF changed to cause this.  There is something wrong with the logic, though, that allows something like this to happen....

Regards,
Ray L.