DIYbanter - View Single Post - Clausing spindle bearings-help!

Ned Simmons wrote:

In article ,
says...
On Sat, 3 Dec 2005 22:44:51 -0500, "Terry Keeley" tkee(no spam)@(or
mail)rogers.com wrote:

Ive not removed bearings from your particular mill..but based on most
angular contact bearings...they should be mounted like this " "

With a hand snug preload.

Are you sure that's right? That symbology is for "face to face" mounting
and everyone I've talked to have said "back to back" is the way to go.

Hopefully, either the inner races _or_ the outer races are clamped together
with a nut ant the other races are just located with a circlip, if at all. If
so, this will define which way round to mount the bearings since the clamping
_must_ set the preload.

In the arrangement being discussed, both the inner and outer races are
clamped together. The nut does not set the preload, only clamps the
inner races together. The preload is predetermined at the factory by
grinding the faces of the races such that the faces are very slightly
offset when the bearing is assembled with zero preload. The proper
preload results from forcing the inner and outer races together.

Ned Simmons

If you are using ultra precision bearings, Ned's information will work
fine. Also look for an identify mark on the inner and outer race of
each bearing. The inner race marks should be lined up on the shaft
and both outer marks should be lined up in the housing. The marks
represent the out of roundness of the bearing and the two bearing should
run with the out of roundness in the same position, to keep the run out
errors to a minimum. Of course the out of roundness you probably cant
even measure in most shops.( less than .0001)

John