-snip-

Making entire one-piece chuck jaws, however, is a much more
difficult task, and not what I was referring to.

Ok. I plan to tak e a look inside my chuck/s. I've not seen much of the
insides outside of some pics that weren't too detailed.

-snip-

Note that wood, even hardwood, changes dimensions with the
ambient humidity. You can't keep any kind of precision with wood.

It shouldn't be too extreme.

A friend made a copy of an old instrument called a
"hudry-gurdy". Not the barrel organs, but rather a stringed instrument
in which the strings were bowed by the rim of a wooden wheel. Well, the
problem was that as the wood dried out, what had started with a nice
round wheel shrunk differently along the grain and across it, so it was
pressing harder on the strings during part of its rotation than during
other parts. It could not be kept in a shape good enough to produce a
steady sound.

I finally machined one for him from plexiglass, which would not
shrink. The only problem was that I put too good a polish on the rim,
and it would not hold rosin to drive the strings. :-) He solved that
with a strip of wood veneer with a diagonal join.

So -- yes, wood *does* shrink enough to be a problem as it
dries. The original ones were almost certainly made with wood which had
been dried for decades before being shaped put to use, not modern
kiln-dried wood.

Solution: Keep a spray bottom filled with water handy. :-)

Hardly. The majority of the instrument was made of wood, glued
together.

Actually, I was referring to the "disk holder" that were were talking
about.

-snip-

Or perhaps brush some liquid insulation around the perimeter of the
disks and let dry. The kind used on electrical wires. It peels off
easily.

I doubt that it would hold very well, but you are welcome to
try, and report back on the results.

It's job would be to just keep the jaws from damaging the workpiece.

Oh -- that is what aluminum soft jaws are for. When they are
machined in place in the chuck (in the lathe) the shape is such that
they will match the curve of the OD of the workpiece, so there is no
sharp edge trying to indent the workpiece.

That's if he had or could find aluminum jaws. :-)

As long as your chuck has two-piece jaws, you can make more
aluminum (or steel) jaws with a milling machine.

That good to know. I was aware that the chucks jaws were made the way
you described.

Thanks.

Darren Harris
Staten Island, New York.