> There is no "run-in" with antifriction bearings. What do you expect to
> change in run-in? There is no wear allowance and if something does
> cause a dimension change in the bearing(s), they are shot. If the
> bearings are properly installed and lubricated, they should be capable
> of full load/full speed right away.
Ok, I need to really spell this out. I seem to recall
reading once about applying a small amount of grease to new
lower spindle bearings of a BP mill. This grease I assumed
was for initial lubrication, and that there was a run-in
procedure to allow the grease to be worked out of the way.
One was not supposed to run the spindle at full rpm until
the grease had been displaced. Running hot was a sign of too
much grease still in the bearing grooves. Perhaps I have
this info confused with lathe spindle bearings. That's why
I DO understand that spindle oil is the proper -ongoing-
lubricant for these bearings. Having small tubs of grease
shipped with both sets of bearings just reinforced that the
bearings needed this initial lubrication.
Run-in, again, refers to running the spindle at lower RPMs
until the excess grease has found it's way out of the way.
At 5400 rpm, this mill will run significantly faster than a
regulr BP step pulley. I also seem to recall that running
ball bearings too fast right after greasing can cause the
balls to stop rolling as the grease piles up in front of
them, causing them to skid, I would assume against the inner
race. This would not be good. This mill is being restored to
manual to sell, and I am touting the new spindle bearings.
It would not go over well with a buyer if he decided to go
run it flat out for a few hours on his first job, and ruined
the bearings. And no, I have not altered anything to get the
5400 RPM, it has a two speed, 2hp motor, and is so rated on
the data plate
SO.... if the grease is a bad idea from the get-go, are new
spindle bearings just installed and used? Should I at least
give them a small shot of spindle oil before installing the
spindle into the quill? Or do the bearings come with
sufficient lubrication to hold until the first shots of oil
reach them from the provided lube point? Having never
replaced spindle bearings before, I'm just looking for
advice and I hope I've cleared up exactly what I'm asking