Russ any input is good. It is a new PS 48v/12A, PMDX-126, 5056D's. During calibration I was running speeds up to 331ipm with no measurable loss of position (with my .0005 indicator). I ran many warm up wizards at that speed though during rapids the max speed is divided by how many axis are in motion. Still no loss. As the holes have 2 rows parallel I would have suspected an error in the transition from 2-3 also had the carriage or gibs been too tight. I did spend considerable time trying to adjust all gibs with an indicator. All of my fasteners are tight. I do have the typical backlash of a linearmotion2008 ballscrew, somewhere in the .002-.003 per axis. Backlash comp deals with it spectacularly.