We received the GMN HCS200/HSK-50 Spindle with the complaint of heavy sound. The reported runout was out of tolerance on a standard test mandrel.

The spindle assembly was dismantled. Checked all the components. Spindle shaft threads were not found in healthy condition. Repaired the threads and manufactured new lock nut to suit the repaired threads. All other components were cleaned and checked thoroughly.

Front side 2 Nos bearings were found almost broken whereas the other two bearings were not in so good condition. Blue matching of spindle nose taper was not up to the mark.

Ground the spindle nose within the accuracy of 1 micron. All the rotating components were dynamically balanced. Then Spindle was re-assembled. Checked the runout which was 1 micron on the spindle nose and 6 micron on a standard test mandrel.