Rockwell 21-100 Spindle Lubrication

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Rockwell 21-100 Spindle Lubrication

Post by JPar » Wed Nov 08, 2017 1:25 pm

How is the spindle lubricated on this mill? There are two ball oilers (one on each side - see attached picture), but I suspect these are just for the quill. If that's correct, then how does one lubricate the spindle bearings?

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Re: Rockwell 21-100 Spindle Lubrication

Post by choprboy » Wed Nov 08, 2017 11:20 pm

You can't really, not without removing the spindle. You can drop the spindle down and squirt in side oiling port, which will coat the top of the spindle body, but the top bearing usually has a seal. The bearings are supposedly suppose to be oil bath, but there really isn't anything to retain it. Kind of sort of works its way down.

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Re: Rockwell 21-100 Spindle Lubrication

Post by jdanke » Fri Nov 17, 2017 11:06 am

The original bearings are/were greased with shields and not intended to be oiled. The originals are deep-groove 'Conrad' bearings that were custom ground for preload and are installed next to each other with the inner shields removed (MRC 108KSF).

Some folks will clean and regrease the bearings. Others replace them with 15-degree angular contact spindle bearings that are preground for light preload. The least expensive versions of those precision bearings are open and intended for an oil bath, but folks will grease them.

Factory greased spindle bearings with non-contact seals are available from SKF, NSK, GMN, and others (they are more expensive). You can call the company and a technician can help with the part numbers. Ones I know of are SKF S7008 CDGA/P4A, NSK 7008CTRV1VDULP4, and GMN KH 6008 2RZ C TA P4+ DUL, and there are lower-cost ones direct from China, e.g., from HXB, but I don't know of the quality.

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