From: sslREMOVETHIS@loganact.com (Scott Logan)
Newsgroups: rec.crafts.metalworking
Subject: Re: .0001" sliding fit
Date: 23 Oct 1998 00:37:14 GMT

I was going to stay out of this discussion, but after seeing some of
the comments, I think it's time I dropped a word or two.

Number 1, NEVER, EVER, EVER LAP AN OILITE BEARING.  The abrasive will
embed itself into the bearing and turn IT into a lap.  You will
quickly destroy your shaft.

According to the manufacturer (yes, I checked), the approved method of
modifying an Oilite Bearing is to "size" or burnish it, or to cut it
with a VERY sharp tool.  Dull tools will tear the material and close
the pores.  At that point, you have a simple bronze bushing.  It is
also recommended not to ream Oilites, except in unusual circumstances.
Reamers have a tendency to tear the surface.

Sizing can be done with a burnishing tool, or by forcing a ball
through, or my favorite, pressing a lathe mandrel all the way through.
In any case, remember that the Oilite will spring back slightly from
the maximum size of the sizing tool.

Once the Oilite has been modified, it will probably need "re-oiling".
For more details, see http://www.loganact.com/tips/oilite.htm

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From: Robert Bastow <"teenut"@ hotmail.com>
Newsgroups: rec.crafts.metalworking
Subject: Re: Oilite bearings - oversize bore ?
Date: Sat, 04 Mar 2000 06:39:50 GMT

I was always taught (and we machined a LOT of big bushings from Oilite stock) to
use a razor sharp tool and to avoid overheating the material.

OTOH, I read that Oilite themselves recommend reamer..even ball burnishing
techniques!

I strongly suspect..In REALLY thinking about it..That the manufacturers probably
know best!  In reality, oilite doesn't have "pores"..It has honking great
(relatively) large interstices, between (relatively) large bronze balls.
Difficult to "smear" closed..and the burnishing probably produces a larger area
of bronze bearing surface..with somewhat smaller..but definitely
present.."pores" leading to larger, back-up, oil resevoir spaces.

In retrospect, I have to face the fact that one is never to old to learn!

teenut

mulligan@advinc.com wrote:

> In article <iqs0cs8ob7km1m0q58eugrqoem5aukjp5b@4ax.com>,
>   Kevin Pinkerton <kpinkert@newsguy.com> wrote:
>
> > A lot of folks have said that you are supposed to only use very sharp
> > cutters in reaming oilite bearings. Reamers probably would not fit
> > this category. The little holes in the surface of the oilite will
> > become clogged and keep the oilite from doing what it is meant to do.
> > I am just repeating what I have been told here before....
>
> Right, I remember that thread from a few months ago.  I do seem to
> recall that Robert B got pretty insistent about something, but I
> cannot remember if it was for, or against reamer use.  But that
> everyone pretty much shut up after he put his comments out.
> I remember some folks said they used reamers for this all the time,
> and others who said they never did as they were sure it would not
> work well.  Some said the 'pores' were way too large to be smeared
> over, and others who said that a good sharp reamer would not do
> any 'smearing' at all.
>
> As Bertrand Russell said, when the experts disagree, then there
> is probably no simple answer to a question.
>
> Jim

From: Ted Edwards <Ted_E@bc.sympatico.ca>
Newsgroups: rec.crafts.metalworking
Subject: Re: Oilite bearings - oversize bore ?
Date: Sat, 04 Mar 2000 08:22:57 -0500

Kevin Pinkerton wrote:

> A lot of folks have said that you are supposed to only use very sharp
> cutters in reaming oilite bearings. Reamers probably would not fit
> this category. The little holes in the surface of the oilite will
> become clogged and keep the oilite from doing what it is meant to do.
> I am just repeating what I have been told here before....

AFAIK, there is no machining operation that doesn't benefit from sharp
cutters.  However, several years ago, I reconditioned a riding lawn
lower which, among other things, needed several oilite bushings
replaced.  These were not available from any source I could find so I
made them from oilite stock.  The operations involved outside machining,
milling (a couple were hexagonal on the outside), boring and reaming
(with both chucking and adjustable hand reamers).  I had no problems
with any of them and all were still in excellent shape at last springs
anual.

Ted