[mcshaner2k]

Hey Guys,

I'm having some issues doing a grid shift on a 2 axis You Ji lathe with a Fanuc 21i controller. I've done grid shifts on many lathes over the years without any issues until today, I'm stumped!

Using parameter 1850 I need to shift the X axis .015

It's been a while so I wasn't sure to add or subtract this number to 1850 X axis. I calculated .015*25400 which gave me 381. I subtracted this number from the current number (300) -381 input+ which gave me -81.

Immediately I get an alarm for 1209 servo overload which tripped the curcuit breaker in cabinet even though the machine hasn't moved, also X over travel, and spindle serial link .. The machine wouldn't go home, etc.. I went back to parameter 1850 and changed it back the original number of 300. After restarting, same problem, same alarms, and to make matters worse when you home the X position it only a moves about 8 inches from X zero (spindle center), this machine has 36" swing.

So my next idea was to call up T0909(boring holder) and sweep the pocket and see where our X is at now. Now the X position is X15.128@ spindle zero. So I figured what the heck I multiplied that by 25400 and added it to parameter 1850 X position. It changed nothing! It's like it completely lost its home position.

I know I'm probably missing something stupid here.. Any ideas?

Once again I appreciate all your help!

[mcshaner2k]

I ended up using parameter 1815 to shift home position. All is good now!