VMC Fanuc 0m sensor problem

Hi there.
First thank you all. This forum was very helpful since I started to work with my machine.
The machine is a 30 years old VICTOR Vcenter-65 with Fanuc 0M-C. And the problem is:
I bought a insize 3d sensor and started calibrating. I've got runout of 0.005mm on the ball. The test I made is that. I ran a program, that machined a 30mm by 30mm square out of aluminum, with 20mm by 20mm pocket inside, then put my indicator on the machine and measure X+ X- Y+ and Y- on both outside and inside.These are the offsets from I've got on every test:
Outside Inside
X+ = 15.068 X+ = 10.069
X- = -14.975 X- = -9.944
Y+ = 14.972 Y+ = 9.951
Y- = -15.054 Y- = -10.038

I was using 10mm end mill, and the machine was going from -20mm to +20mm in both directions while machining. So I've sent the indicator for check on other machines and it's fine.
Is there any parameter that can cause this ?

Thank you in advance and I apologize for my crappy English.

Best Regards
Lazar Dinkov

30 years old VICTOR Vcenter-65
I would check the actual backlash, and the correction parameters.
The machine can compensate for a lot of lash, but tool pressure will still cause problems in cutting.

ifixcnc said:

30 years old VICTOR Vcenter-65
I would check the actual backlash, and the correction parameters.
The machine can compensate for a lot of lash, but tool pressure will still cause problems in cutting.

Click to expand...

Thank you for the answer.
Backlash is 0.005 on the x and z axis, and 0.01 on the y axis. Correction parameters are respectively 10, 8 and 20. The machine was like that when I bought it.

Those backlash's seem good for an 30 year old machine. You must put a 1 in the correction parameter to measure the actual lash. Beyond that I wonder if your spindle may have some looseness?