Kessler DMS100.32.4.FHS Spindle Repair

The Kessler DMS100.32.4.FHS is out of a CNC vertical machining center.  This spindle is oil mist lubricated and stator driven capable of running up to 24,000RPM.

CHALLENGE

Our customer sent in this Kessler DMS100.32.4.FHS spindle stating that they were having coolant get into the taper which wouldn’t allow the tool to properly seat.  Once the spindle arrived at Northland Tool we completed a full disassembly and evaluation.

This is what we found:

• Draw bar pulled low force incoming and the customer also stated they were seeing low pull force
• Once the draw bar was removed from the shaft it was noted there was a missing seal and a sheared O-ring
• The grease on the bellevilles had been washed out and there was heavy rust contamination (Pic 1)
• Front #2 bearing felt worn and gritty when spun by hand
• The middle housing was egged on the ID and OD
• Housing nut to middle housing was very difficult to remove and sustained damage

SOLUTION

The following actions were performed on this Kessler DMS100.32.4.FHS spindle:

• Replace Bolts, O-rings, Bearings, and Draw bar assembly
• Grind-Plate-Grind (GPG) HSK 63 taper due to high run out and visible wear
• GPG 100mm middle housing ID and 117mm OD of middle housing
• Machine O-ring grooves on OD of middle housing
• Skim ID of middle housing nut, Clean spanner holes and face of nut

RESULT

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