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9" Southbend Headstock reworked
(brownnsharp) wrote in message . com...
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!
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
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