9" Southbend Headstock reworked
 

I am cleaning and getting ready to paint anew an old 9" Southbend. I
took the spindle out of the headstock, so I could clean the oilers
etc, and to my astonishment saw a bunch of micro-fine brass particles
around the rear bush. I continued cleaning, and after I had cleaned
the grease and particles out, I found myself looking at a pressed in
brass bushing inside the original South Bend brass bushing....I
think.... The front bushing had a similar pressed in bushing. I am
saying that the headstock casting has two concentric pieces of brass
in each spindle bearing location.

So...My question is what do the original bushings look like? Are they
in two pieces like my lathe? I might add that the workmanship in these
inserted bushings is very high, judging from the finish. Haven't
miked them for accuracy yet. But, if it was not done at the factory, I
need to make a bunch of measurements to make sure I have an aligned
spindle. And be wary of the fit when re-assembling the headstock. I
cannot imagine boring the two holes to great accuracy at the correct
height and parallel to the bed without considerable fixturing, such as
would be available at the factory, but not in the local machine shop.

All in all, a bunch of complications I could do without!

9" Southbend Headstock reworked
 

I am cleaning and getting ready to paint anew an old 9" Southbend. I
took the spindle out of the headstock, so I could clean the oilers
etc, and to my astonishment saw a bunch of micro-fine brass particles
around the rear bush. I continued cleaning, and after I had cleaned
the grease and particles out, I found myself looking at a pressed in
brass bushing inside the original South Bend brass bushing....I
think.... The front bushing had a similar pressed in bushing. I am
saying that the headstock casting has two concentric pieces of brass
in each spindle bearing location.

So...My question is what do the original bushings look like? Are they
in two pieces like my lathe? I might add that the workmanship in these
inserted bushings is very high, judging from the finish. Haven't
miked them for accuracy yet. But, if it was not done at the factory, I
need to make a bunch of measurements to make sure I have an aligned
spindle. And be wary of the fit when re-assembling the headstock. I
cannot imagine boring the two holes to great accuracy at the correct
height and parallel to the bed without considerable fixturing, such as
would be available at the factory, but not in the local machine shop.

All in all, a bunch of complications I could do without!

Original SB9 bearings were just highly-finished holes in the iron headstock.
The polished hardened spindle let a setup like this run almost forever. Sounds
like your original bearings wore out and were bushed.

GTO(John)

9" Southbend Headstock reworked
 

9" Southbend Headstock reworked
 

9" Southbend Headstock reworked
 

Reboring something like that headstock wouldn't be too hard with the
availability of a somewhat larger lathe. You'd just need to fasten
the headstock onto the carriage on the other lathe and use a boring
bar between centers through the bearing holes, line boring, it's
called. Getting everything lined up, shimmed up, fastened down and
the cutter protrusion adjusted before beginning is the real trick.
With the proper cutter geometry, you can end up with a very nice
surface finish and the holes on both bearings will be aligned with
each other. Whether they are aligned with the lathe bed depends on the
skill of the machinist. Takes minimal tooling but a fair amount of
skill in setting up.

You'll probably end up making a test bar anyway, no telling what it's
been through.

Stan

Exactly! I know it can be done well, but was it?? Boring it parallel
AND getting it to line up in height with the original tailstock
requires more than casual attention to detail. With a big enough
milling facilities, you could mount the whole lathe bed on the mill,
zero in on the tailstock, indicate parallelness to the bed, and bore
away.

I was surprised from the response that S.B. bored the cast iron of the
headstock for the bearings. The only lathe I had heard of that did
that was the Myford ML10 I really don't have a problem with the
concept.

At my present rate of work on the lathe, while painting the house, and
doing other things, I will probably know what the lathe is like
sometime near the end of summer. I have another old southbend, that I
use every week, with a good headstock and a bad bed that I might swap
parts with if this one is too bad.

9" Southbend Headstock reworked
 

In article , brownnsharp
says...

Exactly! I know it can be done well, but was it?? Boring it parallel
AND getting it to line up in height with the original tailstock
requires more than casual attention to detail. With a big enough
milling facilities, you could mount the whole lathe bed on the mill,
zero in on the tailstock, indicate parallelness to the bed, and bore
away.

Which is typically why the headstock is fitted first, and the
tailstock is done to agree with that.

Doing the headstock bore requires that it be a) at the correct
height, b) aligned in the vertical plane with the bed axis, and
c) aligned in the horizontal plane with the bed surfaces.

Jim

==================================================
please reply to:
JRR(zero) at yktvmv (dot) vnet (dot) ibm (dot) com
==================================================

9" Southbend Headstock reworked
 

When you have the headstock set up for boring, would it make sense to
bore for some sort of tapered roller bearing to replace the stock
sleeve bearing?

Thank you,
Jeff Rininger

jim rozen wrote in message ...
In article , brownnsharp
says...

Exactly! I know it can be done well, but was it?? Boring it parallel
AND getting it to line up in height with the original tailstock
requires more than casual attention to detail. With a big enough
milling facilities, you could mount the whole lathe bed on the mill,
zero in on the tailstock, indicate parallelness to the bed, and bore
away.

Which is typically why the headstock is fitted first, and the
tailstock is done to agree with that.

Doing the headstock bore requires that it be a) at the correct
height, b) aligned in the vertical plane with the bed axis, and
c) aligned in the horizontal plane with the bed surfaces.

Jim

9" Southbend Headstock reworked
 

In article , Jeff Rininger
says...

When you have the headstock set up for boring, would it make sense to
bore for some sort of tapered roller bearing to replace the stock
sleeve bearing?

No, not on a 9" south bend. The ones where the steel spindle
runs right in the cast iron headstock casting don't really have
enough meat around the bearing to put in a tapered roller bearing.

Because the bearing has to be shim-adjustable by clamping down
on the clamp bolt, that region has to be thin enough to flex
and close down when the shim is removed and the bolt tightened.

It's not clear that tapered roller bearings are really better
in this application, either. Those journal bearings in those
machines may well be one of the most widely disseminated kind
of spindle ever made - south bend must have made a bazillion
of those 9" machines, and most of them are still out there
kicking around, working.

Jim

==================================================
please reply to:
JRR(zero) at yktvmv (dot) vnet (dot) ibm (dot) com
==================================================