On Sat, 27 Mar 2004 16:56:11 -0800, "larry g"
wrote:

I have a new to me Hz mill. In the package were three arbors, one 1" and
two 1 1/4". This mill, a Dufour, French made, has two round shafts for the
arbor support like a K&T. The arbor support hole is 2" bushed to 1 3/4"
with an oillite or brass bushing, Within this bushing is a roller bearing
that has a bore of 1". So I'm assuming that when running the 1" arbor I
set up the spacers and cutter as needed and put the arbor nut on the outside
of the roller bearing using the inner race of the roller bearing as the last
spacer.
When setting up the 1 1/4" arbor I'm assuming that the roller bearing is
removed and that the bushing on the end of the arbor runs in the brass
bushing.
Some of my confusion is coming from looking in the catalogues and finding
that the running bushings on the arbor are standard at 1 5/8" or 1 7/8" OD.
Do most arbor supports have a plain bushing to support the arbor? Or are
rolling element bearing common?
thanks in advance
lg
no neat sig line

The bearing is strictly for arbor support. This method is very common
on the bigger horizontal mills. As you say..you may simply run the 1"
arbor though the bearing and put the nut on the outside. As long as
the bearing is a tapered double thrust bearing, it will work fine.

If the bearing is your typical cage rollers, not thrust bearings, ,
then it will collapse sooner or later if you crush it between the
spacer and the nut. Be sure to check!

The KT mills use the outboard bearing..but the end of the arbor has
the stub. I believe this is called a class A arbor. What you need to
do, is install your cutters, your spacers and your nut..and there
should (maybe..often G) be enough stub left sticking out to put into
your bearing. If the stub is smaller, simply make a brass or steel
spacer that is 1" OD, with the appropriate ID for the stub.

Ive seen a goodly number of arbors which included their own bushing
AND bearing which is designed to go into the arbor support. I did a
quick search but was unable to find an example on the net. I can take
some pictures of a KT this coming week, with the arbors and the
bearings/bushings for each arbor.

Typically, the arbor support has a oil reservoir that holds oil to
lube the roller bearings in the support, and the bushing that goes
inside the rollers, for each arbor.

Another method, is the rollers have an ID (or a bushing) that is the
same size as the OD of the spacers. The nut is installed, and its
smaller than the OD of the spacers..and the arbor support bearing
simply slides over the last couple spacers, no stub needed.

Be sure to check that arbor support bearing. If its simply a cage with
roller bearings running parallel to the arbor..with no provisions for
thrust..you will kill it by putting the nut on the outside and
squeezing the bearing.

Gunner

"As physicists now know, there is some nonzero probability that any object will,
through quantum effects, tunnel from the workbench in your shop to Floyds Knobs,
Indiana (unless your shop is already in Indiana, in which case the object will
tunnel to Trotters, North Dakota).
The smaller mass of the object, the higher the probability.
Therefore, disassembled parts, particularly small ones,
of machines disappear much faster than assembled machines."
Greg Dermer: rec.crafts.metalworking