MNC – Mechanical Numerical Control

[duncan webster 1Participant @duncanwebster1]

UK government intervention is usually disastrous (both parties). Austin & Pickersgill were successful until nationalised and forced to amalgamate with loss making shipyards. Leyland trucks were successful until lumbered with Austin Morris. Find a copy of a book called ‘Blunders of our government’, a bit out of date but full of extremely expensive decisions which went completely wrong. Unless an industry is strategically important, if it is dying, let it. Propping it up only prolongs the agony. The only exception is if the industry is dying because imports are subsidised by foreign governments, in which case tariffs are appropriate

[Martin KyteParticipant @martinkyte99762]

Actually manufacturing in the UK has quadrupled since 1948.

See https://www.ons.gov.uk/economy/economicoutputandproductivity/output/timeseries/k22a/diop

The decline in UK manufacturing is a comparison with the rest of the world and we should remember we started from a very high world position. That’s not to say we cannot do better particularly with high value, high tech items but the fact remains we are making 4 times as much stuff now as we did in 1948.

regards Martin

[Martin KyteParticipant @martinkyte99762]

Fair comment Duncan. I feel that the intelligent intervention of government is more to do with creating the right infrastructure and economic incentives to build new industries coupled with access to education and training than to directly intervene everytime an industry is in trouble. There are exceptions though. Rolls needed a helping hand after the RB211 nearly bankrupted it and then went on to be very successful.

regards Martin

[Martin Kyte]

On Martin Kyte Said:

Actually manufacturing in the UK has quadrupled since 1948.

See https://www.ons.gov.uk/economy/economicoutputandproductivity/output/timeseries/k22a/diop

The decline in UK manufacturing is a comparison with the rest of the world and we should remember we started from a very high world position. That’s not to say we cannot do better particularly with high value, high tech items but the fact remains we are making 4 times as much stuff now as we did in 1948.

regards Martin

Not volume of stuff – it’s value that’s improved.  What’s gone is the multitude of firms making low-value items.  In 1902 John Masefield celebrated this in ‘Cargoes’:

Dirty British coaster with a salt-caked smoke stack,
Butting through the channel in the mad March days,
With a cargo of Tyne coal,
Road-rails, pig-lead,
Firewood, iron-ware, and cheap tin trays.

All gone with the exception of road-rails.  They’re a high-end steel product, much tougher than the 1902 equivalent, and still made in the UK.

Dave

[Martin KyteParticipant @martinkyte99762]

Dave is correct I should have said 4 time the value of stuff. There are no stats on the number of items but value is perhaps more important than number of items?

My Dad was Financial Director for a packaging company and at one time half their output was low cost Smiths Crisps boxes. He made them cancel the contract as they were not making any money from them although they were taking half the capacity of the factory and they were turning away more lucrative work.

So personally I’m glad we have improved the value.

regards Martin

[PeteParticipant @pete41194]

I’ve been in a few shops recently that were using the plain non Man Au Trol VTL’s. I think the much more simple manual only versions Bullard made are still pretty common, or at least they are in North America.

But those VTL versions in the video aren’t something I’d known about or how that type of control worked, so thanks for posting the link. I’d guess someone looked at a player piano one day and thought up part of that programmable drum. A computer, servos and ball screws look pretty simple in comparison to three full boxes of resetable and adjustable control start and end points. It’s still hard to really find much about them, but what the U.S. Navy were using on there battle ships towards the end of WW II for completely mechanical computers to provide firing solutions over long distances are even more complex.

[duncan webster 1Participant @duncanwebster1]

Does anyone know how plug board capstan lathes work? If you do can we have a description? I ask because my first industrial job had them, but I was far too reticent to ask how they worked.

[Michael GilliganParticipant @michaelgilligan61133]

I think this may help a little, Duncan:

https://www.lathes.co.uk/ward-plug-programme-lathes/

… but I’ve just cleared the cookies off my iPad and can’t face the prospect of de-selecting all those ‘legitimate interest’ ones again, just to read the page.

MichaelG.

[Michael GilliganParticipant @michaelgilligan61133]

https://youtu.be/YKKOER5daqg?feature=shared

Ward control box ^^^

MichaelG.

[mgnbukParticipant @mgnbuk]

Does anyone know how plug board capstan lathes work?

I used to – once, a long time ago. Place I started my apprenticeship at had a Herbert No. 4 bar auto capstan lathe with a Hepworth plugboard controller. This was a bit more modern than the Ward controller that Michael linked to, having several TTL control boards well populated with 74xx series logic gates as well as a lot of relays.

I can’t recall much about it now (it was late ’70s when I had to play with it) but it was both a PITA and a boon for me. PITA because when it played up it took a lot of fault finding, with me often spending hours watching the thing cycle trying to observe the point at which it went wrong. We had various “tools” to try and get to the bottom of problems, such as freezing spays, hot air guns, logic injectors etc. for when a particular suspect ic was identified. A boon as Hepworth Engiineering were just outside Holmfirth about 10 miles from the works. They had test rigs, so if a board was suspect it was arranged that I took the board in to them by arrangement to get it tested under load. I got the “up to 1300cc” car mileage rate for my 150cc motorcycle, plus I got to ride my bike on works time.

My recollection is that it was usually the boards that were the issue – can’t recall that the limit switches / sensors gave much bother. And it only usually played up when it hadn’t been used for a while – once up and running it was reliable if kept running. This was pretty much the case for the NC / CNC machines there as well – turn them off and they could take days to get back up and running again, so they were not turned off when not being used. The stack of lead acid memory back up batteries on the GE 1050T CNC control would only keep the memory (64 bytes core memory IIRC) up for 12 hours anyway.

I did an installation of a new machine in Czechoslovakia before the fall of the Communist Bloc & the factory there had a milling machine that ran basic cycles to limit switches, with the “program” being punched into 35mm cinema film stock. The programmers showed me the film stock they were using – a B & W propoganda film where Lenin could be seen delivering a speech when the film was held against the light.

Another precision electromechanical system I saw was on American Keller horizontal copy mills, which used constantly rotating ac motors to drive the axes via electomagnetic clutches controlled via precision switches in the stylus head. The system was set to feed along one axis and “peck” along the other, with the cut depth being controlled by the stylus being kept in contact with the master being copied. The stylus tip was the same size & profile as the cutting tool, so the parts could be first roughed out and subseqeuntly finished using different tools and “peck” widths. have seem pictures of these machines producing aircraft propeller blades during WW2, but the one I saw was making automotive press tooling.

Nigel B.

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