Our customer reported X and Y axis positioning accuracy error.They made Four holes on them parts.Hole pitches are shorter than target.They have 0.04mm error on X axis and 0.02mm error on Y axis.They have one more same machine and no problem on it.We measured backlash by test indicator.It was just 2,3 micron on X and Y with N12=0 We checked B/S assembly condition to make sure.We found not proper adjustment on support bearing pre-load and B/S pre-tension.We need more thicker spacers to adjust X and Y B/S tension.Also support bearing retainers for two end each axes to adjust pre-load.Could you agree to supply these parts free of charge. In addition that these adjustment may not help our original problem.Because there are no backlash problem on machine with current assembly condition.Please give us idea if you have advice to solved problem.