Old school lathing/ barrel/ receiver threading

[uscra112]

Machinists didn't even have what we call "high speed steel" until about 1910. Prior to that, the best tool steels would slump or crumble if run fast enough to get hot. High Speed Steel was as much a revolution in the machine shop as carbide is today. A lot of machine tools that were OK for the old "Mushet" type cutting steels couldn't be run fast enough, and had to be scrapped and replaced.

[KCSO]

For years I used a smaller South Bend and did barrels between centers with a dog. As to how well they could do barrels that way until 1955 a hand made bench rifle held the record for a 10 shot group at 200 yards. The most accrate rifles I have made used hand cut barrels from Bill Large. Harry Pope got by with a pedal lathe and made the best barrels of his time.

Most interesting is a lathe made by hand in a Jap prison camp that was capable of working to a thousands of an inch. All hand made for scrap.

[ulav8r]

Lathing is the installation of wood strips on a framed wall as a base for the application of plaster as a wall finish.

[John Taylor]

The big rifle companies like Winchester and Marlin used thread cutting mills for the actions so the timing was the same on all the actions. This way you could take a barrel of one gun and screw it onto another action and expect it to time correctly. Try that with a Stevens where each barrel was fit and timed to an action. Most likely the barrels from the big companies were threaded first, checked with a gauge and then threaded into a jig before contouring. I thread and chamber to fit an action and then make all the other cuts, like octagon, rib or integral sight ramp. A whitworth hex bore is done on a single point rifling machine with a flat cutter instead of one designed for cutting the groove. I did one several years ago just to see if I could.

[uscra112]

John, as far as my history goes, thread milling was only used to make leadscrews in that time frame. We were still doing it when I worked for Hoffacker in the 1980s. Required a dedicated machine, and the process was slow. Do you have anything specific about Winchester milling barrel shanks? A bit of machine tool history I'd like to ingest.

Phil

[John Taylor]

John, as far as my history goes, thread milling was only used to make leadscrews in that time frame. We were still doing it when I worked for Hoffacker in the 1980s. Required a dedicated machine, and the process was slow. Do you have anything specific about Winchester milling barrel shanks? A bit of machine tool history I'd like to ingest.

Phil

Read about it someplace years ago.

[jmorris]

the only difference between yesterday marching and today machining is to day it is faster.

Depends, I can do a number of manual lathe operations faster than you could draft the file for a CNC, convert it with master cam, load it into the machine, setup offsets.

I’d be done before you even got to the machine to turn it on.

That said, they could do the exact same operation much faster and with equal precision as a human, over and over. Setup is it the killer for them.

[uscra112]

But job-shop CNC (e.g. Fanuc) can be programmed right on the machine for simple jobs.

This how the Japanese killed the American machine tool industry. American controls mfgrs. built to the "off-line programming" model. Programs written in an engineering dept, carried to the machine on punched tape. The aerospace users liked that. It kept control in the hands of the engineers. Programs even had a tool number, and it was forbidden to use any other to make a part, or to alter one without nineteen signoffs. But these machines weren't profitable. Cincinnati, Kearney & Trecker, Lodge & Shipley, Bullard and deVlieg et.al made their take-home pay selling traditional manually operated machines. Ditto Brown & Sharpe, Monarch, Lodge & Shipley, LeBlond, South Bend, American, Axelson, Warner & Swasey.

Enter the Japanese, with their Fanuc shop-floor programmable machines. Job shops ate 'em up, depriving the big domestic machine tool names of their cash flow and profits. In just ten years most of the American industry was on the ropes.

I was there. Broke my heart to see it all happen. One after another they were bought up by conglomerates, squeezed for whatever assets they still had, and the husks dropped in the dustbin.

/rant

[M-Tecs]

I am more old school I can run manual machines faster for most single parts. That being said with the new machines with good operators leave me in the dust.

[EDG]

The real difference that killed the US machine tool industry was the ridiculous prices of union made machine tools produced in the US. The excellent Japanese machines were often 1/3 to 1/2 the price of an equivalent American made machine. I bought several dozen machines back in the early 80s and they were all Japanese. The Fanuc controls were pretty standardized and cheap then. The American machines had a variety of different controls such as Allen Bradley, GE and a hodge podge of proprietary controls.

But job-shop CNC (e.g. Fanuc) can be programmed right on the machine for simple jobs.

This how the Japanese killed the American machine tool industry. American controls mfgrs. built to the "off-line programming" model. Programs written in an engineering dept, carried to the machine on punched tape. The aerospace users liked that. It kept control in the hands of the engineers. Programs even had a tool number, and it was forbidden to use any other to make a part, or to alter one without nineteen signoffs. But these machines weren't profitable. Cincinnati, Kearney & Trecker, Lodge & Shipley, Bullard and deVlieg et.al made their take-home pay selling traditional manually operated machines. Ditto Brown & Sharpe, Monarch, Lodge & Shipley, LeBlond, South Bend, American, Axelson, Warner & Swasey.

Enter the Japanese, with their Fanuc shop-floor programmable machines. Job shops ate 'em up, depriving the big domestic machine tool names of their cash flow and profits. In just ten years most of the American industry was on the ropes.

I was there. Broke my heart to see it all happen. One after another they were bought up by conglomerates, squeezed for whatever assets they still had, and the husks dropped in the dustbin.

/rant

[uscra112]

There were a couple of Japanese MT builders who supplied high quality mechanics. Hitachi Seiki comes to mind. Most in that period were, frankly, crap. Flame hardened cast iron ways of dubious quality were the rule rather than the exception on all the cheaper machines.

I knew very well one M.T. house in New England whose selling technique tacitly admitted that the small machining centers he peddled would not last five years of continuous production. His pitch to job shop owners was to do all the fixturing and programming as a package deal, and showing them what to bid on jobs to guarantee a nice profit before the machine would be worn out. They were never worth rebuilding, as I determined numerous times while working for a highly respected M.T. remanufacturer in Rhode Island.

As a rebuilder, I also had to do a couple of times with Shin Nippon Koki machines, which were very poorly made. The larger they were, the worse they were. Bearings that should have been shrink-fitted into gearbox housings often simply fell out when the 'box was being dismantled. Gears so badly heat-treated that they were worthless after only 3 or 4 years service.

The fundamental geometry factors of common Japanese machining centers I encountered, (i.e. straight, flat, square and parallel), never came up to the standards that American machines easily met. I did a short stretch in 1990 working as a consultant, relocating a large Long Island job shop. The owner had two Mazaks, a Makino, and a Nomura HBM, not one of which would pass their own alignment specs, no matter what I did, (and I was by that time more than expert at machine tool installing). I have long thought in retrospect that the castings/weldments were not fully stress relieved, and had warped in the first years of service. (A problem that choked deVlieg when they tried to built machines from weldments.) The big five-axis SNK horizontal he had was a joke. He wanted to do 5-axis work for Grumman, but we could never have met their tolerances, the thing was so sloppy. He had also bought sight unseen an SNK CMM, which we finally gave up on. No way to even get it assembled, much less running, without major relapping of the granite bed and table ways.

Lost motion in ballscrews was another bugaboo I often ran into while using my laser interferometer to recalibrate them. Most Japanese builders made little or no effort to really eliminate it, because it could be comped out by the CNC. Really low-end machines used rolled ballscrews, which had to have springs in the nut to take up the variance in the thread pitch. Needless to say, they weren't very stiff at all.

I'll stop now.

/rant (again)

[vagrantviking]

https://museumofmaking.org/about/

Not going to the dawn of time but quite a collection of early industrial equipment.

[uscra112]

https://museumofmaking.org/about/

Not going to the dawn of time but quite a collection of early industrial equipment.

Quite a collection indeed. Reminds me of a shameful failure in my career - I lived and worked in the Detroit region for 15 years, and never went to see Henry Ford's collection.

[arjacobson]

I knew guys that worked in the tool room at Oliver tractors that could run jig borers with jo blocks and indicators to get holes within .0001.. Those guys were some crafty people.. BTW why is it old machinists are usually interesting and crusty individuals?? LOL

[country gent]

Its interesting to see the difference from the old guys to new. Im not so sure the CNC haven't hurt the trades some as far as skill level and pride. To the old guys I wirked under a hacksaw files and other hand tools were pression tools. They new how to run a file and bring in radiuses, angles and edges. They could move a center drill spot over as needed if it started off with a small hammer and chisel. Hacksaws were used routinely for cutting roughing in slots and keys. They had way more understanding of the trades. One of the most used machines from that era was the shaper now almost non existent. I have used shapers to cut dovetails and keys among other things.
The new guys see the file as a tool to remove burrs. most don't have a hacksaw or chisels in their boxes anymore. They don't understand hand fitting, scraping, lapping or other hand operations.

[Lionel Allen]

I worked in a machine shop/welding shop for a few years. Hated the CNC machines. Was too boring to work in that department. I preferred welding and fab work. Had one idiot that wasn't smart enough to be able to remove a burr from pieces. Had to be carefull not to get sliced on his work. Couldn't complain to the foreman because they were friends.
The old machinist they had was an interesting character: he was old school Dutch, and didn't cut corners.

[country gent]

Those old guys are something to watch and see in action. They don't seem to be doing much at any given time but at the end of the day there is a pile of parts on their bench done. lol
They had learned and knew how to work smarter not harder.
I worked with a couple in the first shop and they were amazing as to their knowledge, skill, and craftsmanship. Also in the later shops I worked were some of the old worlds craftsman. At the last shop were a bunch of fine craftsman that were very skilled and competent. It was a pleasure to learn from them and work with them over the years.

[John Taylor]

Just for fun I made a Whitworth barrel when I finished my rifling machine. Have not built a rifle yet to use it on because I have not figured out the bullet mold yet. One of the things that has increased production is carbide tooling. With HSS tool bits I can cut 50 surface feet per minute, carbide will run 250 or 5 times faster. Also carbide will cut harder metal. I make screws out of spring steel that has already been heat treated. While HSS will cut it, it gets dull faster. Carbide will cut bearing steel which HSS will not touch. Then for the really hard stuff there is ceramic tool bits.