Dan found this :
I have a customer that was haveing problems with his large cnc router.
The problem was with only 1 axis the X axis.
He is using my 4 axis control unit with 4 G201's and my 42V 25A power
supply. He is using my 1303 oz in motors and the 752 oz in motors on
the X and Z axis. After several phone calls we finally located the
problem. The problem was with windows Update. Every 40 minutes it
would activate in the background and cause the X axis to loose position.
I'm passing this on in case there are others that are having phantom
problems. I had him run the optimization procedutres and now his
machine can run continuously for 8 hours with no lost steps.
Dan Mauch
www.camtronics-cnc.com