Heian M9205B Spindle Repair

This Heian M9205B spindle is from a 4-head bridge type CNC router.  It comes equipped with an oil mist lubricated and stator dirven spindle capable of running up to 17,000 rpm.

CHALLENGE

This Heian M9205B spindle arrived at Northland Tool and Electronics with fine sawdust packed into every external orifice.  It had also penetrated the spindle interior, contaminating the front bearings and causing them to fail. The BT-35 tooling taper was heavily worn with >30µ runout, the drive dogs (keys) were worn, and the incoming tool retention force was extremely low. We also discovered that the OD of the front & rear bearing journals of the shaft were worn undersized & fretted where the bearings locate, and both the front and rear housing ID’s were worn oversized.

SOLUTION

The following actions were performed on this Heian M9205B spindle:

• Clean all parts of the spindle
• Replace all bolts, o-rings, and gripper balls
• Replace preload springs and seals
• Replace bearings
• Rework damaged drive dogs
• Grind, chrome plate, and finish grind (GPG) the tooling taper
• GPG both bearing journals
• GPG both the front & rear housings

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.