Hi All,

So I started a new job and as a part of that I have inherited the duties of fixing thier existing CNC machine. Having built my own 4x4 Avid/Mach3 machine I am not a complete newbie but this one I am working now has some interesting challenges.

The X and Y axis' in this machine are LinTech rails with NEMA 34 sized servo's on them. Everything seems to be wired and mechanically functioning properly.

So the first challenge is that the Y axis slave will initially start to move in perfect unison with the Y axis but after 4-5 inches it dramatically slows and as such it racks the Y axis. It does this in both directions and all along the axis. I have checked the motor tunings between the two in Mach3 and they are the same there. It is also interesting that if I keep the speed slow enough, it does not do this... Anything over 70ipm and I have racking issues but not below that speed.

Needless to say.. I would rather not run at 70ipm if at all possible.

The second issue is that the Y axis is losing position... I can run a program and bring it back to home and it can be a half an inch off in either direction... I will be running different tests today to see if I can narrow it down to a single servo or if they are doing it in tandem.

Any idea or suggestions would be greatly appreciated.

Thanks in advance,

Mick