Is my spindle failing?

A rumble, whine or grinding that rises with rpm is the classic sound of a bearing on its way out. It will not get better, and running on it turns a bearing set into a shaft and housing repair. Pull it while it is still a bearing job.

Some warmth is normal. A spindle you cannot keep a hand on, or one that is hotter than it used to be at the same cut, points at bearings losing preload or lubrication, or at a cooling fault on fan- and air-cooled units.

Vibration means imbalance or bearing wear. Check the tool holder and the collet first; if a fresh, balanced tool still vibrates, the rotor or bearings need attention.

Chatter marks, witness lines and a surface that needs more sanding than it did are often the first sign a customer notices. Bearing play shows up in the cut before it shows up as noise.

Put an indicator on a ground pin in the collet. Runout that has grown since the machine was new means bearing play, a damaged taper or a bent shaft. A rebuilt Perske or Colombo spindle reads in single-digit microns.

On ATC spindles a weak drawbar, worn gripper fingers or a scored taper cause slow changes, dropped tools and tools that walk out of the holder. Drawbar and taper work is part of a rebuild.

Overcurrent trips, hard starts and lost torque can be windings, an encoder, a cable or the drive itself. We isolate the motor from the bearings before quoting, so you do not rebuild a spindle that needed a cable.