I have found an issue on the last batch of fadals that were built for auction( issue has been found on 2 machines now).I have found that the bolts holding the bracket under the table that the ballnut attaches to on the x axis are too long and bottoming out,causing the block to be loose and rock on the pins.there are 3 bolts recessed into this block and a long 5/16 allen is needed to get them out.remove them and cut about 1/4'' off and put them back,do 1 at a time.I found this by first having circle interp. and finish issues,tested backlash and got .0020,tested the screw by putting the indicator on the table and the tip on the thread got.0017 backlash on the screw(should be less than .0003). i removed the x tail support bracket,waycover,and lower sheetmetal pan.i out an indicator on the bottom of the table and the tip on the black ballnut bracket and jogged 1 click set 0 and 1 click the other way and the block moved .008 should be 0.if you find this shorten the bolts.most techs may overlook this (i did at first)as this not a normal issue and the factory machines this block after installtion so they should have caught this then.