Hi,
I would like to install oilite bushings in an aluminium casting for a
small steam engine which presently has poor bushings. Would the proper
procedure be to drill the casting undersize and then ream the bore to the
correct size for a snug fit? For a 1/4 in O.D. bushing would I ream the
hole to exactly 1/4 in or should it be slightly undersize? Can you buy a
reamer that is slightly undersize for this purpose? What about adjustable
reamers?

Thanks

Rod

"Rodney" wrote in message
...
Hi,
I would like to install oilite bushings in an aluminium casting for a
small steam engine which presently has poor bushings. Would the proper
procedure be to drill the casting undersize and then ream the bore to the
correct size for a snug fit? For a 1/4 in O.D. bushing would I ream the
hole to exactly 1/4 in or should it be slightly undersize? Can you buy a
reamer that is slightly undersize for this purpose? What about adjustable
reamers?

Thanks

Rod

A lot depends on the shaft size. Typically, Oilite bushings are made
oversized, both ID and OD, but when you press them in the properly sized
hole, they are the desired finished size. Without a micrometer to determine
the exact size you need, it's a crap shoot. The shaft would determine
that, and it may or may not be nominal. Assuming you want an undersized
reamer, yes, they are readily available, particularly if you shop for a
chucking reamer. These are intended to be run in a spindle and don't work
worth a damn by hand, so if you're restricted to hand work, don't buy one.

I'm not convinced you'd find an adjustable 1/4" reamer, but I'm not sure
you'd want to do this job without the use of at least a drill press, if not
a mill.

In order to insure that the holes are properly aligned, and not bell mouthed
because of hand misalignment, it would be in your best interest to not
attempt this by hand. If bushing are to be installed that should be
aligned, boring the holes would be desirable, and for that you don't need a
reamer.

Hope this helps, Rodney. I realize it's not the greatest news, but it will
keep you out of trouble.

Harold.

The perfect bushing install is black magic! Start with burying chicken guts
on a full moon...then follow Herold's advice.

"Rodney" wrote in message
...
Hi,
I would like to install oilite bushings in an aluminium casting for a
small steam engine which presently has poor bushings. Would the proper
procedure be to drill the casting undersize and then ream the bore to the
correct size for a snug fit? For a 1/4 in O.D. bushing would I ream the
hole to exactly 1/4 in or should it be slightly undersize? Can you buy a
reamer that is slightly undersize for this purpose? What about adjustable
reamers?

Thanks

Rod

"Tom Gardner" wrote in message
...
The perfect bushing install is black magic! Start with burying chicken
guts
on a full moon...then follow Herold's advice.


And, throw the bushing in the freezer before you press it in. You'll do less
damage to your aluminum that way.

snippage

I'm not convinced you'd find an adjustable 1/4" reamer, but I'm not sure
you'd want to do this job without the use of at least a drill press, if not
a mill.

In order to insure that the holes are properly aligned, and not bell mouthed
because of hand misalignment, it would be in your best interest to not
attempt this by hand. If bushing are to be installed that should be
aligned, boring the holes would be desirable, and for that you don't need a
reamer.

Hope this helps, Rodney. I realize it's not the greatest news, but it will
keep you out of trouble.

Harold.

I've gotten 1/4" adjustable reamers, the ones that are readily
available are the sort that are one-piece with longitudinal slits and
an end tapped for the adjustment set-screw. These are usually what's
available in the smaller sizes, when you can find them. I also have
the multi-blade sort, these took a bunch of working over to get all the
blades to cut and to get a decent finish. The one-piece adjustable
types don't necessarily return a straight hole for your efforts,
they're kind of barrel shaped to start with. The best sort of reamer
for doing multiple in-line bushings is one intended for electric motor
rebuilding, this has a long pilot so you ream one bushing with the far
end supported by the other bushing. A fellow could probably make up
something like this with a lathe, making a D-bit in the center for the
reamer part.

The rule of thumb I've read and have used is .001" interference fit per
inch of bushing diameter, then ream the shaft hole to desired clearance
after pressing in. For under 1", I've always used .001" interference
between housing hole and bushing. A loose fit could be compensated
with one of the anaerobic adhesives they have these days, or just use
the stuff to start with.

Stan

Dave Lyon wrote:

"Tom Gardner" wrote in message
...
The perfect bushing install is black magic! Start with burying chicken
guts
on a full moon...then follow Herold's advice.


And, throw the bushing in the freezer before you press it in. You'll do less
damage to your aluminum that way.


If you freeze the bushings and heat the aluminum to 250 degrees, the
bushings will drop in, but you only got a couple of seconds to get them
in the right place so I put a mechanical stop on the end so it is placed
right.

John

Thanks all for the help

Rod

"Harold and Susan Vordos" wrote in message
...

"Rodney" wrote in message
...
Hi,
I would like to install oilite bushings in an aluminium casting for a
small steam engine which presently has poor bushings. Would the proper
procedure be to drill the casting undersize and then ream the bore to the
correct size for a snug fit? For a 1/4 in O.D. bushing would I ream the
hole to exactly 1/4 in or should it be slightly undersize? Can you buy a
reamer that is slightly undersize for this purpose? What about
adjustable
reamers?

Thanks

Rod

A lot depends on the shaft size. Typically, Oilite bushings are made
oversized, both ID and OD, but when you press them in the properly sized
hole, they are the desired finished size. Without a micrometer to
determine
the exact size you need, it's a crap shoot. The shaft would determine
that, and it may or may not be nominal. Assuming you want an
undersized
reamer, yes, they are readily available, particularly if you shop for a
chucking reamer. These are intended to be run in a spindle and don't work
worth a damn by hand, so if you're restricted to hand work, don't buy one.

I'm not convinced you'd find an adjustable 1/4" reamer, but I'm not sure
you'd want to do this job without the use of at least a drill press, if
not
a mill.

In order to insure that the holes are properly aligned, and not bell
mouthed
because of hand misalignment, it would be in your best interest to not
attempt this by hand. If bushing are to be installed that should be
aligned, boring the holes would be desirable, and for that you don't need
a
reamer.

Hope this helps, Rodney. I realize it's not the greatest news, but it will
keep you out of trouble.

Harold.