Depends on the field. In the electronics field, in particular
in things like the lead spacing on ICs (e.g. your plain old 74LS00 quad
nand gate IC -- 14 pin DIP) the spacing is given in "mils" which are
thousandths of an inch. (Think "Mili-inch". :-) Look on the data sheest
for these old ICs. I don't know *what* the lead spacing on those
postage-stamp chips where all the leads are bent down and soldered flat
to the circuit board. They might be still spec'd in mils, or may be in
mm by now. The DIPs like above had the pins on "100 mil centers", and
in two rows "300 mils apart". (Or was it "400 mils"? -- I should check
sometime soon to refresh my memory.)
And you *know* that the EEs and such *never* talk to the
machinists in the company. (Or if they talk, they don't listen. :-)
Mili-inch is probably it. I picked up the term from my father, who worked
in the rubber industry starting in about 1940. It seemed very` common
both in academic circles and in the aerospace industry through the early
1980's. The academics preferred to use microns (.001 mm) but everybody used
mils when talking about machinery.
Apologies for the confusion,
This is an Army copy of the 9" SB manual:
The manual for my Heavy 10 gives more about testing and maintenance. I
don't know how much of it applies to yours.
The photos in the link no longer work, but the discussion is useful.
It looks like there's something in the slot below the spindle pinch
bolts on my 10k, if it's not a shim then I'm puzzled.
For the moment I'm in "look but don't touch" mode. The spindle feels
fine and I'm trying to figure out what the dominant errors in the lathe
are. The saddle bed is worn about .020", the tailstock center is visibly
below the axis of the spindle, maybe .020". It would be interesting to
know the skew between headstock and tailstock axes, but it's not obvious
to me how to measure it.
Seems like the first step is make a few parts; if they're good enough
it may be wisest to just oil the machine and use it.
Thanks to all for reading and your advice!
My 13x42 Clausing and my 15x52 Clausing and my Hardinge HLV-H are
hobby machines. Value is about $17,000. My cost was under $3k for
One of the hobby uses they are in my shop...putting rifle barrels on
actions. And building rifle actions from bar stock.
And building off road Stuff for friends various off road rolling
That depends. The larger ones are, but the 6" ones can be
either an Atlas, or the 109 series is by AA machines, and is a very
substandard machine, with (among other problems) a spindle which is too
small in diameter, and the first crash is likely to produce a bent
My Atlas/Craftsman is an older style, with bronze bearings
instead of the roller bearings of the later ones. And I have better
machines now, so it is retired. :-) I did not like the square bed ways.
(One of the things which AA did better -- prismatic ways at least, even
with too wimpy a spindle diameter. :-)
And I think that the Wards may sometimes have been Logan lathes
instead of South Bends. (May vary with when.)
The tooling that matters is a 4-jaw chuck and a toolpost. After much
searching for a good used chuck, which I couldn't check without
running it, I bought a new Bison semisteel 4-jaw. 20 years of light
hobby work hasn't loosened it at all.
Polytechforum.com is a website by engineers for engineers. It is not affiliated with any of manufacturers or vendors discussed here.
All logos and trade names are the property of their respective owners.