"Terry Keeley" tkee(no spam)@(or mail)rogers.com wrote in message
.. .
I'm restoring my 1963 Clausing 8520 mill ( pictures here if interested
http://gallery.intlwaters.com/thumbnails.php?album=323 )
and in the process am replacing the spindle bearings. I've read through
many posts on the Yahoo Group and have just gotten more confused.
Talked to a few bearing "engineers" (ya right) at SKF and they don't seem
to
have solid answers either.
The spindle takes a pair of 7205 angular contact bearings that are held in
place by a locking washer and nut. I was able to find on the MRC site
that
the torque on the nut should be 23-50 ft-lb. but can't seem to find
answers
to the following:
Should the bearings be mounted "face to face" (where the contact lines of
the bearings converge inward), or "back to back"?
I can order bearings that are ground and sold as a matching set in either
"b
to b" or "f to f" that when mounted together and the retaining nut
tightened
give a "light preload".
I can also order bearings that are not matched but are for "universal
pairing" that are about half the cost and are made to mount either way.
Some posts on the Yahoo Group mention that to apply a preload to these
bearings a shim is needed between them either on the inner or outer race,
others say none is needed. If the bearings are made to mount either way
how
can they be preloaded without the use of a shim? If needed how thick
should
it be?
The machine came fitted with standard bearings and no shims so I can't go
by
what was there.
Any experts here? Thanks in advance!
FWIW, the replacement bearings I ordered from Clausing a few years ago are
Fafnir 7205WN SU. I haven't installed them yet, but it looks like it might
be necessary pretty soon. There are one or two files in the Yahoo Clausing
group that describe bearing replacement, I think. I've archived off two
from there or elsewhere, complete with pictures. Email me if you can't find
them at the Yahoo group.
Following is the only info that Clausing could supply me on the spindle
(note that no "sample" was attached):
ASSEMBLING SPINDLE AND QUILL ASSEMBLY FOR CLAUSING MILL
1. Press 044-005 bearings one at a time on 701-004 spindle. Apply pressure
on inner race only and use DB mounting as shown in instructions supplied
with bearing - sample attached.
2.Slide 932-011 lock tab washer on spindle with inner tab in keyway.
3. Turn 537-020 nut on spindle and tighten securely against inner race of
bearing. Bend a tab on the 932-011 lock washer into a matching slot of the
537-020 nut.
4. Place the spindle in the 631-001 quill - 044-005 bearings in the threaded
end.
5. Press the 044-006 bearing on the spindle as far as it will go - apply
pressure on inner race only and support spindle on nose only.
6. Assembly 708-001 oil seal in 641-008 retainer as shown in attached
sketch.
7. Turn 641-008 retainer in quill -firm but not too tight.
8. Place M6-214 lead ball in threaded hole in quill and lock retainer with
#10-32 x 3/16" socket set screw.
INSTRUCTIONS FOR REMOVING NO.8520-25 V-MILL SPINDLE ASSEMBLY
1. Remove (2) 1/4" socket set screws from No.537-014 knurled nut located on
top of spindle, then remove knurl nut from spindle.
2. Remove (4) 1/4" machine screws (2 on each side of guard) which screws
guard No.342-020 to head casting. remove guard by pulling forward.
3. Remove (4) screws which screws plate No.386-009 containing pinion and
compound gears. Tap plate lightly on edge while prying outward with screw
driver to remove from dowell pins.
4. Remove socket set screw in No.233-001 dial and lift or pry up on stop
screw No.696-007 until top of screw is against spindle pulley, push quill to
bottom position.
5. Remove 1/4-20 socket cap screw holding stationary stop to face of quill.
With stop removed, remove quill assembly from head, reverse procedure to
install quill. Caution --be sure when installing spindle pulley guard that
brake lever is engaged in brake ring slot.