I just noticed that when I engage the fine adjust on the Z axis, the knob turns over one full turn before the head starts to move. I would like to get rid of this "slop". Does anyone have any ideas? I was thinking that I could put a shim behind the "rack" that is mounted on the column. This would move it out and make it tighter on the "pinion". Am I on the right track with this thought? And help would be great!