Were there any advances in lathe technology in the last 40 years?

DROs? Electric relays and contactors instead of drum switches? MY new lathe, a Precision Matthews, is eons better and more user friendly that my 1942 Sheldon was

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 important points.

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.

Jon

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 different.

My '41 10EE has a D1-3 spindle. Other than electric drive improvements, very little changes were made in this lathe over the 50 years they were made.

Karl

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.

jw

I expect the only advances have been in the CNC arena, with powered tooling, additional heads, axes, sub spindles and all the wonderful stuff on the "Swiss type" CNC lathes.

This would be my impression, as well.

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?

Iggy, 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 understand. Steve

"Steve Lusardi" fired this volley in news:gkg4j1$o40$03$ snipped-for-privacy@news.t-online.com:

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.

Yes? No?

LLoyd

Yep. One day. I will not decline. Perish the thought.

Your test bar is well on its way

i

The Leblonde we have at work has replaceable bedways. Hate to see how much replacing them would cost. They do not appear to be scraped.

Wes

Wes fired this volley in news:czQal.144768$ snipped-for-privacy@en-nntp-08.dc.easynews.com:

Wes, I was thinking more along the lines of designing it to use a standard precision-ground stock material. That stuff isn't expensive, at all.

LLoyd

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.

Wes

-- "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. :-)

Enjoy, DoN.

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.

Jon