Cincinnati 10HC 2500 Spindle Repair

The Cincinnati 10HC 2500 is a large CNC horizontal machining center.  It comes fitted with an oil mist lubricated and gear driven spindle capable of running up to 4,000 rpm.

CHALLENGE

Our customer employs this horizontal machining center spindle in the manufacturing of world-class metal cutting and welding equipment. They contacted us because the 2-speed gear-driven spindle was very noisy during operation in the low range, less so in the high range. The bearings were definitely loud when rotated in assembly incoming, and felt worn when rotated after disassembly of the spindle. We also observed that the 45 tooling taper ID was in poor condition with insufficient tool contact, and that the 125mm housing bore was worn oversized and out-of-round despite previous plating and grinding. Additionally, we noted that the tool retention gripper fingers had significant wear and that one drive key was worn while the other was severely damaged.

SOLUTION

We completed a kiss grind of the 45 tooling taper ID, and a grind, chrome plate, and finish grind of the 125mm housing bore. We rebuilt the spindle with all new bearings, bellevilles, grippers, drive keys, gasket, seals, 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.