Coordinate system problem backtool lathe.

I have a back tool lathe.
After I start and home the system.
when I touch off the tool for Z I get a number of -1.x in Z of G54.
If I then use NGCGUI to create a program and the run the program I receive an out of range error on Z.
if I then touchoff Z again I get a number of 11.xxx in G54 and all works well from that point on.
This is making me crazy as I have not been able to correct this.
This only happens after I startup the system
It does the same thing in axis and gmoccapy.

jim

Hi

Have a look at this thread and see if it helps regards how back tool or slant bed lathe co-ordinates work.
www.linuxcnc.org/index.php/english/forum...vs-g43-offsets#49638

I am not sure how when you touch off you get a number, it should be whatever you enter, but I would edit the emc.var file in your config and remove all the values.

Then make sure you min and max limits in your ini file are set correctly, in terms of machine co-ordinates, not G54 or whatever.
Home should be top right, furthest extent of the axes and the operating envelope is described by the min limits, because all values will be negative from machine 0,0

regards