Matsuura RA-1X Spindle Repair

The Matsuura RA-1X is a CNC vertical machining center made for high production cutting.  It comes equipped with a grease lubricated and coupling driven spindle capable of running up to 8,000 rpm.

CHALLENGE

This Matsuura RA 1X spindle was sent to us because it suffered a catastrophic failure of the rear roller bearing.  Upon inspection we noted that the cage was destroyed and the rolling elements were loose in the spindle shaft.  The rear of spindle was flooded with sticky coolant residue, likely from a leaking rotary union.  Residue was also found behind the front cover, but this had not migrated to the front bearing set.  The drawbar shaft end, grippers, and gripper sleeve were severely damaged from corrosion and not functioning smoothly.  Lastly, the shaft tooling taper had 8µ runout and will need to be ground.  No other dimensional deviations were noted on this spindle.

SOLUTION

The following actions were performed on this Matsuura RA-1X spindle:

• Clean, inspect overall dimensions
• Kiss grind tooling taper to improve runout
• Replace bearings, drawbar assembly, crush rings, push-connect air fitting, o-rings, and assembly screws

RESULT

After reassembly of all components, adjusting bearing preload, and undergoing break-in and testing procedures, this spindle passed our final quality inspection before being returned to our customer with a 1-year warranty.