On 2008-04-06, Tom wrote:
DoN. Nichols wrote:

[ ... ]

My 12x24" Clausing (from 1957) has a dial which is calibrated 0.000-0.100
on a 10 TPI leadscrew. It was a light industrial machine in its day, not
a hobby toy. I suspect that the dials reading in direct diameter change
are more recent machines.

My Monarch (1958) has a crossfeed dial graduated 0.000-0.500" on a 4tpi
feedscrew as well as graduated 0.500-0.000" for internal boring. Apart from
cosmetic differences, the dial has the same graduations as a local 1944 Monarch
of the same size. However I imagine my dial is a lot bigger than yours as
it's 5" in diameter, so maybe Clausing costing clerks had a say in your
dial and the subsequent graduations? :-)

I certainly would not want to try to read 0.000-0.500" on a dial
the diameter of mine, while 0.000-0.100" works out fine. How big a
Monarch is yours -- the 10EE or one of the larger ones? That 4 TPI
leadscrew suggests a larger machine to me.

Note that I have a spare compound from an earlier Clausing
picked up from eBay, and the dial diameter is about half the one which I
have. If I ever have to put that one into service, I will transplant
the dials from the newer one onto it -- or make a new set of dials.
(Actually, since the dial is a collar around the actual mounting of the
crank to the leadscrew, all I need to do is to turn and graduate a
larger collar -- and make something to hold the index line to match it.

Enjoy,
DoN.

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