"Vintage" CNC

My wife changing jobs has revealed this apprentice piece that has been sitting on her desk at work for many years.

It is a very simple piece of CNC machining, but it has a history. It was created in the summer of 1981 in the apprentice training school at BAe Weybridge (Brooklands). We were the first year to have access to a shiny brand new CNC mill. May have been a Bridgeport or a Cincinnati, my memory is not that good. We were writing raw G code on a Commodore PET (no graphics or even a hard disk) and then transferring it onto the mill via punched tape. The instructor had been on a very basic course, so he was learning along with us. It was all very exciting for us young apprentices at the time! Alas we only had a few days of time allocated, so this was the one and only piece created.

Through holes to bolt it to the desk to stop it growing legs ?

Nigel B

Denford Triac and Orac cnc machines a couple of years later must have been well received with the ability to program from computer, save the program on disk for future use and/or send the G code program to the machine for execution. I am still using an original DOS program from that era for writing G code programs to send to my Orac lathe and see no advantage in changing for 95% of the work I do.

Emgee

Like the idea, but the holes are blind, as per drawing

It's rather like the Mercan definition of "vintage" ie something over 30-40 years old. In fact, even g codes have been around since the 50s, with other CNC systems in use well before then.

My Shizuoka CNC milling machine was shipped in 1983, yet it used a well established system - nothing particuarly ground breaking. In those days, I believe most programs were simply typed in to the console (in g code), with programs being backed onto cassette tape or paper tape if necessary.

I expect there will be a few members on this forum who can predate the experience....

Murray

Murray, there was a reason I put vintage in quotes

Certainly in the Weybridge machine shops there were many NC machines that dated from the 50's and 60's. Some ran on Mylar punched tape, which read and executed the commands sequentially direct from tape.

Sorry, wasn't being personal!

Didn't realise they were using Mylar (PET) in "paper" tapes back in the 50s. PET was an amazing invention and was the focus of my father's entire working life at ICI, from tire cord, through polyester fibre (Terylene, Crimplene etc!), artificial leather, drinks bottles and stretched film (BoPET - floppy disks, cassettes, insulators, dielectrics etc). Amazing stuff!

Murray

If you really want vintage machine tool control, try this one.

In 1956, the Electrical Engineering Department bought the U.S. license to EMI (Electric and Musical Industries) controls— the most advanced numerical control of the time—and installed them on machine tools for a U.S. Air Force Wright Field program.

To reflect increased focus on electronic controls, electronic gages, and hydraulic valves, in 1957 the Electrical Engineering Department became the Electro Hydraulic and Gaging Division. While operating under this name, the company shipped its first EMI control bringing electrical control to the hand wheel.

The EMI main tool room was similarly equiped.

Edited By KWIL on 17/06/2017 14:42:32

You can tell it's old. When was the last time you saw an ashtray on someone's desk?

> Didn't realise they were using Mylar (PET) in "paper" tapes back in the 50s.

The PET Stuart referred to is an early 'personal computer'!

Neil

My first job when I came out of the army in 1969 was to machine parts on a "tape" drill. The "tape" was a paper ribbon around one inch wide from memory. All worked well provided the bosses son who did the paper punching upstairs hadn't made any mistakes. I still remember his red face when the Y axis moved on with a brand new 2" (I seem to remember) still in the 'ole. Like a carrot it was and so effortless

Rik

.

Memorable for the fact that it had no printed 'Set-up Manual" ... Reviewers at the time were quite impressed that the installation instructions, on cassette tape, were the first thing to be found when opening the carton.

MichaelG.

but they were a plumbers nightmare, blowing seals and leaking and then the concensus was to concentrate on servo and stepper controls

And hot and noisey, as well as taking up a large amount of room for the oil tanks, coolers etc. And very, very finicky about cleanliness - machines were shipped with "flushing blocks", which were used to replace the servo valves to allow the system to be flushed for several hours if the hydaulics had to be worked on.

But before reliable, high power electronic switching devices, there was little option if you wanted a high torque servo drive. Mostly hydraulic motors driving ballscrews, but some (certainly some Newall borers, probably others) used hydraulic cylinders. Taken plenty off & replaced them with modern electric servo drives (and managed to interface a modern control to the old servo valves on a Newall cylinder driven jig borer) in my last job.

Mylar tapes were only used for the Diagnostic and Parameter tapes on the machines I was set on to learn the maintenance of in 1977 - much too expensive to use for day-to-day operation. BTW, if you come across any unused rolls of 1" tape, don't bin it - it hasn't been made for ages & there are still a few die-hard users who will pay whatever you want to ask to get hold of it !

Nigel B

One of the first NC machines I worked on was a Wadkin drill with an EMI control. It was used for jig boring type work. I was just out of my time as an electrician and keeping this going was difficult as the glass inductosyns were unobtainable so the travel had been shortened by using undamaged ones from the extremes of travel. Valves were also going out of fashion by the mid seventies. Another curio was a Marwin with all hydraulic movement and an Olivetti NC control but the main table was a ball screw with an hydraulic motor. Moog valves were indeed the main control part of the hydraulics, setting the null on these was a task I remember. The hydraulic power pack was quite a beast and was prone to failure, you could tell when it was on its way out as the noise level would become deafening even though it had an acoustic enclosure. The table also moved on PTFE pads which was quite unusual in the seventies. Moog valves became common as muck when an army of hydraulic robots arrived at the end of the seventies. The Japanese seem to have the remarkable ability to keep hydraulic fluid in the pipes and only a layer of dust covers their power packs.

Mike

Edited By Mike Poole on 17/06/2017 17:04:28

My degree final year project in 1987 was a program to translate between the ISO standard language for NC machines at the time (ISO5700?) and the Heidenhain TNC controller language. So translating from 1 non g-code language to another. Completely pointless.

It's good to see that the language that survived had such deep roots, and that some bits survive from so early.

Regards

Richard.

Anyone remember plugboard capstan lathes. They always looked like black magic to me

The first NC Mill I saw at Vickers Weybridge was run off paper tape about 2" wide and was PNEUMATIC, i.e.: a jet of air was detected being blown through the oblong holes punched into the tape - would that have been PNC ??
The next machine that I saw (not allowed to touch) was the Med Head mill, see **LINK**
BobH

If you want to get really old school look at the cam operated auto-lathes, nothing but an electric motor turning a central shaft, the rest is mechanics, amazing really.

start at about 0:40 if you want to see the tools working. 

Michael W

Edited By Michael-w on 18/06/2017 08:51:22

Anyone remember plugboard capstan lathes. They always looked like black magic to me

Oh yes - very profitable for me as an apprentice was a Hepworth plugboard capstan lathe. This used a Herbert (No. 4 Pre-optive IIRC) as it's base with a Hepworth plugboard control. The control had a couple of dozen TTL logic circuit boards, which were frequently "iffy" - many boring hours sat waiting for an intermittent fault to appear to use signal injectors, heat gun, freezing sprays etc. to try & identify where the problem was. Usually though (& this was the profitable bit for me) I had to take the suspect board to Hepworth's works outside Holmfirth (our works was in Brighouse) to have it run through the test rigs there. I ran a sub-250cc motorcycle & got the small car mileage rate, so a nice run out in the middle of the day paid for my fuel for the week.

In the late '80s I comissioned & trained on a couple of new CNC VMCs installed in Czechoslokvakia (pre the end of Communism). One of the milling machines there used 35mm movie film as the "tape" - a very basic control moved the axes in sequence to limit switches, the relevant switches being punched onto the "tape", which was then spliced to be an endless loop. The programmers I was working with brought out the reel of film that they had been given to use and, holding it up to the light to see a few frames, it was obviously an old propoganda film, with an actor made up as Lenin on a podium giving an animated speech.

Nigel B

EMI MEC Plug board auto capstan

http://www.cottandco.com/en/lots/emi-mec-type-s-plug-board-auto-capstan-lathe-2