QT15 Lost Motion on X axis (Backlash?)

Hey guys, I have a curious issue with the X axis on my QT15. I had some diameters come out a little off so I checked my BL parameters vs a dial and saw interesting results.

- When I mpg from 0-4 thou and then back again on a tenths indicator the dro is ~.0006 off (back at original dial location)
- When I move from 0-4 thou on a tenths indicator one direction only I'm ~.009 off(!)

Not sure what is going on. If I adjust my BL parameters to be something high like 40 tenths and jog at 1x with the hand wheel I get this:

First click BIG jump on the indicator due to high BL parameter, then subsequent clicks motion slows down, dial doesn't read any movement for some mpg steps and if I continue the dial ends up far short of my expected distance based on the DRO/MPG.

I understand that thrust bearings or a bad screw/ballnut would allow backlash to occur when changing direction, but its odd that the axis just fails to move enough distance when adjusting by tenths. Hoping someone else has had a similar experience or that I'm missing something obvious here...

Thanks!

Don't forget the machine shows diameter reading, the clock is showing radial....

Wow, I was very much on auto pilot trying to read the indicator for BL and almost had a heart attack when I convinced myself the machine was 4 thou out of wack, of course you are 100% correct that was the "issue." Doh!

I'm surprised someone took the time to reply to something so obvious, thank you!