fanuc gn6 contol on a warner & swasey sc-17

[DavidC1949]

is there a parameter that will help my problem ?

I cut an 8" bore and it is to size then when I cut a 16" bore it is +.01

i know that i can use the offset to make it right,but is there a parameter that can change the gain on the servo or something to correct this ?

Thanks David

[Chris D]

Originally Posted by DavidC1949 is there a parameter that will help my problem ? I cut an 8" bore and it is to size then when I cut a 16" bore it is +.01 i know that i can use the offset to make it right,but is there a parameter that can change the gain on the servo or something to correct this ? Thanks David

Hi David, that is a pretty strange problem. I don't know the proper solution, but I would check the mechanicals of the machine, slop in the ways or perhaps a really worn ball screw. There are parameters for dealing with pitch error on the ball screws - I believe they are called pitch error comp. I have no idea on how to set them though -sorry.

Chris

[Fireflowers]

Hi David,
In the Fanuc manual it explains how to set the ratio of measurment to distance moved.
It is done on initial machine build and would be unusual for this to need changing as its not something that would normally need tampering with.
Unless someone has tried to adjust these to take up wear on the machine(also doubtful).
The pitch error is easy to change and is explained fully in the fanuc manual.
Have read it but never done it!
Hope this helps, John.

[Dan Fritz]

David, This may be a silly question, but ... Is your tool on center ?

The pitch error compmensation in the system 6 is easy to adjust, but I just can't believe that there's .0100 error between and 8 inch bore and a 16 inch bore. That's only a 4 inch difference along the X axis ballscrew. There must be some other factor here ...