After completing my 2 axis CNC Conversion on my Tawiwan BP clone knee mill, I've found what I believe is an unacceptable amount of "backlash" in my y axis, between 0.0018"-0.002". Both axes use new Hiwin ballscrews and my x axis is nearly perfect, only 0.0003"-0.0005". I've upgraded to a solid, and might I add beefy, steel ballnut yoke. I've also upgraded the bearing mounts to one's made of steel. I'm running SKF 7204 ac bearings on both axes, preloaded in back-to-back fashion. I can jog the y axis with tenths indicator in the spindle up against the fixed vice jaw, then set my DRO (glass scale) and indicator to zero. Next, I jog in the opposite direction exactly 1.0000" according to Acorn CNC. My glass scale reads 0.9980". Now I jog back towards the vise jaw 1.0000", according to Acorn, and my indicator and glass scale will zero out perfectly. I've repeated this test several times with the same result. I switched my way oil to ISO46 hydraulic oil hoping to cut down on stiction of the ways but that did nothing to help the backlash. I'm really stumped by this, any suggestions?