Here's the issue. One of my steppers on the X axis has a little lag time when moving. The X is made up of two motors on a R&P system. When I make movements one of them doesn't immediately move but when it does catch up everything is fine. Tuning isn't a problem...checked that. Is it possible to get backlash in a R&P system? Can I make a change in Mach? It seems like the response time is a hair off.