I have converted a cincinatti bed mill using Rutex drives (2020) and Mach 3. Recently I have developed backlash in the X axis, approximately .03". I went through and tried to determine if it was mechanical and where. I used a dial indicator off of the table and rocked the ball screw back and forth and could not find any slop in the screw and nut. I pulled the motor off and checked the pulleys to see that they were tight to the shaft. No problem . The gear belt was in excellent shape. I retightened the belt tension. No improvement. I removed the cover on the encoder (US Digital EB5d (not sure)) and put a target /pointer out of a piece of tape. I rocked the ball screw back and forth with a vise grip on the end of the shaft. I see no encoder change on the screen. The motor was fighting to reposition itself.
To eliminate the problem with regard to positioning I went into the config. section of mach 3 and enabled the backlash on the x axis with a value of .0315". This works fine in running a program but trying to locate or center and moving the axis .0001" does not work. I spent around 20 minutes trying to indicate a center with a coax indicator- futile. ANY Suggestion woul;d be appreciated. I had previously blown the rutex card on this axis. This was due to a heat problem. I now have three seperate muffin fans serving the mother board. Tom E. if you are out there I would appreciate a response.