EMCO Maxxturn 45 Some damage is significant, and some is not
EMCO Maxxturn 45 - Grease lubrication, Pulley driven, 6300 rpm
The bearings of this CNC turning center spindle were extremely noisy when rotated by hand incoming. The spindle interior including the bearing grease was heavily contaminated with a rusty brown substance. The bearings had fretted the 80mm journals, especially the rear journal which had a deep wear band (-45µ) where the #3 bearing is located. The front bearing journal dimension was within ISO (±4µ) but it had excessive runout. The shaft face & OD taper showed evidence of wear and we measured high runout on the bolt-on face plate. There was light fretting of the housing bores but we did not address this as it was dimensionally insignificant.
We performed a green grind, chrome plate & finish grind of the 80mm bearing journals, and we also breezed the shaft face & OD taper to improve the runout. After cleaning, we installed the bearings, o-rings & assembly screws. We adjusted the preload, assembled all components, then test ran the spindle to break in the new bearing grease and balanced the spindle before shipping to our customer. This rebuild was accomplished on an expedited basis.