Haas VF-4 Spindle Repair

The Haas VF-4 is a larger CNC vertical machining center.  It can come fitted with this grease lubricated and stator driven spindle that is capable of running up to 12,000 rpm.

CHALLENGE

When this Haas VF-4 spindle arrived at Northland Tool and Eletronics it spun freely, but the bearings felt scratchy when spun by hand.  Upon disassembly and inspection, we noted that the front and rear bearings were contaminated with a brown particulate.  The ID taper was above guage line and the front OD nose of the shaft showed signs of run out, both will need to be addressed.  The ID shaft nut was severely damaged and will need to be re-made.  Lastly, we noted that the gripper balls were slightly worn and should be replaced.  No other dimensional deviations were noted for this repair.

SOLUTION

The following actions were performed on this Haas VF-4 spindle:

• Clean, inspect overall dimensions
• Replace bolts, bearings, o-rings, and drawbar assembly
• Kiss grind the ID taper
• Kiss grind the OD nose shaft
• Make a new ID shaft nut

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.