My lathe is about 40 years old. I have looked at quite a few more
recent lathes. While newer ones may be, well, newer, be a little more
accurate, etc, i did not yet see any features on them that were
principally new. Well, one could be electronic drives on some of
them. But what else?
Well, my circa 1968 Sheldon R-series 15" lathe had
a BUNCH of patents on design details of the
machine. Some of them are not totally relevant,
but the basic headstock design is pretty unusual.
The main gearbox is on the motor, not in the
headstock to remove vibrations. Unlike old-style
belted headstocks, though, the input shaft and
pulley does NOT run on bearings on the spindle,
but has its own coaxial bearing set on the
headstock casting. The direct drive uses a PAIR
of hand-scraped drive keys so it doesn't provide
any off-center thrust. The only gears in the
headstock are for the backgear. The headstock is
lubed by oil churned up by the bull gear and
tossed onto a "gallery" in the top of the
headstock. This has holes that drip oil over the
One other thing about newer, high-end lathes is
the increase in both spindle speeds and through
holes. This lathe, although a 15" machine, comes
standard with 1250 RPM, and had an option for 2500
RPM. (I'd be scared to spin an 8+ inch chuck at
2500 RPM, and haven't gotten a collet chuck for
it, yet.) The spindle through hole is 2.25",
which is real nice. Also, newer spindle face
designs such as L00 and D1-x have become quite
popular. (Mine has a D1-6.)
Some of the other features on the Sheldon are a
double universal joint at the driven end of the
threading leadscrew. I assume this is to prevent
any cyclical forces from being applied to the
carriage. Also, the power crossfeed and
longitudinal feed is driven by a keyed driveshaft,
not a keyway in the threading leadscrew. Also,
these power feeds are driven by multiplate
clutches, not gears. Clutch slip force is easily
adjustable from nuts in the center of the
crossfeed and carriage cranks. So, if you have a
crash, no gears get teeth broken off. Higher-end
lathes often have automatic tripoffs set up on all
the feeds, so micrometer stops can be set to drop
out the feeds.
The crossfeed nut has an anti-backlash section.
If you get the taper attachment (which I didn't,
DARN it) it is telescopic, meaning the crossfeed
handle ADDS to the taper attachment motion. This
makes cutting tapers a lot easier. This is
accomplished by having the taper attachment move
the crossfeed nut.
There probably are still more things that are
common on larger, toolroom lathes, one-shot
oilers, larger motors, DROs, etc.
Manual lathes have changed VERY slowly in the last century. Quick-
change gearboxes came out around 1900, gear heads in the 20's (?), D1
spindles around the 60's (?). My 1965 South Bend is an update of a
1920's model. A lathe from the Civil War era might have a belt or
chain drive to the feed screw but the parts on the bed weren't much
Are you kidding? Have you ever considered CNC? How about screw
machines, B-axis mill turns, sub spindles, live tooling, crown
turning, mill feed turning, robotics, barfeeds, ect.
Manual machines is a small part of the whole.
Automatic screw machine, Christopher Spencer, 1873;
Production machinery has improved constantly, but there is very little
on a small manual lathe that Oscar Perrigo didn't describe in 1916 in
"Lathe Design", from Lindsay Books.
I'd like to know when and how the vertical milling machine was
developed. I think they evolved from die sinkers and vertical
attachments for horizontal mills. The first Bridgeport is at the
American Precision Museum in Vermont.
Already sort of mentioned - but variable speed electronic drive and
rolling contact spindle bearings, especially to enable higher speeds
in order to take advantage of carbide tooling.
Those seem to be the primary places where old iron looses out to
modern imports, especially if you have to pick only one lathe - do you
get the one with large swing and suffer low speeds when trying to turn
small things with carbide, or do you get the smaller one with high
speed and have workpieces you just can't turn?
Most of the new inovations were for mass production and automation. The tool
room lathe is pretty much the same as it has been for 50 years. However,
there are huge differences in quality and accuracy between brands and
models. Your lathe, although very nice, is a medium market machine. Most of
the manual machines made today are low and medium quality machines. There is
a very low demand from industry for a high end manual machine today, hence
their scarsity. I have three lathes. My 10 inch SB ((1980) and 13" SB (1984)
are both medium machines. The 10" was designed in the '30s. The 13" is a
late model SB design made in Taiwan (good Chinese). My 18 x 54 Lodge &
Shipley (1979) is another matter altogether. This is a high end machine. I
won't even try to tell you all the features this machine has, but it is a
joy to use, 24 speeds, all the threads and leads you could ever want. It
even has bed ways made out of tool steel and are replacable. All three have
taper attachments and work flawlessly. They all do the same thing, but there
is no comparison, the L & S has the others beat hands down. If you ever have
the opportunity to use a high end machine, don't turn it down. Then you will
"Steve Lusardi" fired this volley in
Which brings up a good question. What would you think about taking an
otherwise decent machine that has excessive belly in the ways, and
milling it for replacable wear strips?
I know the initial milling and scraping of the new way beds would have
to be done with precision. But after that, it seems it would be
inexpensive and easy to drop in new wear strips of a pre-ground
precision flat stock.
Wes fired this volley in
Wes, I was thinking more along the lines of designing it to use a
standard precision-ground stock material. That stuff isn't expensive,
My r.c.m. folder in forte agent got corrupted, after having Agent recover what
was left, I
may not have threading that is showing your message in proper context.
"Additionally as a security officer, I carry a gun to protect
government officials but my life isn't worth protecting at home
in their eyes." Dick Anthony Heller
[ ... ]
What about a toolpost grinder. That should count as powered
tooling, and should be old enough to fit beyond the 40-years in the
"Subjet: " header. :-)
Also -- for additional heads -- try the slotting heads and
cherrying heads for Bridgeports.
And even the CNC stuff almost makes it back. IIRC, the
manufacture date of my Bridgeport BOSS-3 CNC was 1977, so that is 30
years, and NC existed for some time prior to CNC. (There, the computer
was in the central office, and it spewed out punched tape which the
machines read and moved as appropriate. If you needed a circle or a
thread, you had to punch all the steps needed to make the motions on the
tape, instead of just calling out a G-code and waiting for the machine
to generate the motions with their local computer.
Granted, the powered tooling has made major strides in power
through the extra spindles. :-)
If you regrind or otherwise refurbish the bed and
then fit the carriage with Moglice castable bedway
liner, you likely will never have to regrind a
hardened bed again.
In heavy production, you might have to recast the
Moglice every 10 years or so, but that could
actually be done over a weekend.
I did this on a Sheldon R15-6, and it worked out
amazingly well. I know the Moglice will outlast
me, but then I am not a production shop.