Okuma Cadet Mate 4020 Spindle Repair

The Okuma Cadet Mate 4020 is a CNC vertical machining center.  It comes fitted with a grease lubricated and pulley driven spindle capable of running up to 8,000 rpm.

CHALLENGE

This is a classic example of one company (Okuma) that builds the machine, while another company (Setco) manufactures the spindle that is installed in the machine. Our customer did not realize this until the spindle was pulled when it began making noise and exhibiting runout on the tool. The bearings were quite loud when rotated in assembly incoming, which was not surprising as the front and rear Inpro/Seal bearing isolators had failed. Coolant had almost completely washed all the grease out of the front bearing triset and had heavily contaminated the rear pair. While the resulting loss of preload likely contributed to the observed runout on the tool, we also measured significant runout in the tooling taper ID, and the tool retention gripper fingers had severe wear as well.

SOLUTION

We completed a kiss grind of the tooling taper ID, and rebuilt the spindle with all new bearings, bellevilles, grippers, front and rear Inpro/Seal isolators, o-rings, and assembly screws.

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.