Milltronics TTC-60 Spindle Repair

This Milltronics TTC-60 spindle is grease lubricated, stator driven, and capable of running up to 10,000 RPM.

CHALLENGE

Our customer sent in this Milltronics TTC-60 spindle stating that the spindle had been crashed a few times and the taper was reground in the machine.  When it arrived at Northland Tool we completed a full breakdown and evaluation where we noted there was a broken air fitting on the actuator that was broken prior to arrival.  It was recorded that the front bearings were contaminated with coolant and the grease was washed out.

We then performed a full dimensional evaluation and found a few issues that will need to be addressed.  First, the ID tooling taper was bell mouthed and no longer in spec for a Big Plus taper.  Second, the grippers were heavily worn and cracked.  Lastly, the rear bearing shoulder had high run out.

SOLUTION

The following actions were performed on this Milltronics TTC-60 spindle:

• Clean, inspect overall dimensions
• Replace bearings, bolts, o-rings, bellevilles, grippers, and air fitting
• Grind, plate, grind (GPG) the 40 ID Big Plus tooling taper
• Kiss grind the rear bearing shoulder

RESULT

After reassembly of all components and adjusting bearing preload, we put the spindle through a rigorous break-in and testing procedure to make sure it passes our final quality inspection. See below for the passing test reports:

Front Bearings Vibration Analysis Spectrum:                 Rear Bearings Vibration Analysis Spectrum:

This spindle passed our final quality inspection and was returned to our customer with a 1-year warranty.