Haas VF-2SS Spindle Repair

The Haas VF-2SS is a CNC vertical machining center that comes equipped with a high speed spindle.  The “SS” stands for super speed and means that the spindle is capable of running up to 15,000 rpm.

CHALLENGE

This Haas VF-2SS spindle sounded very loud when spun by hand incoming.  Upon a closer inspection, we noted that the taper ID had good run out measured incoming, but there was visible damage to the ID and chamfer.
The actuation ring was very difficult to remove from the shaft due to the bolts being worn down and deformed, ultimately they became stuck in the ring.  All 3 bearings show signs of contamination and oil from the bearings was dark grey and gritty.  There were several bellevilles broken on the drawbar and falling apart when removed from the shaft.  After completing the disassembly we then measured the critical dimensions of the spindle.  We found that the taper ID had slightly high run out when measured bareshaft (4µ).  No other significant dimensional deviations were noted for this repair.

SOLUTION

The following actions were performed on this Haas VF-2SS spindle:

• Clean, inspect overall dimensions
• Replace bearings, o-rings, assembly screws, and gripper balls
• Replace drawbar assembly and actuator ring bolts (customer to supply)
• Kiss grind the taper ID and chamfor

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.