The power of standardised nuts

[Richard_C]

This article is interesting, there is so much we accept as normal now but there has to be a first time



https://www.theguardian.com/artandd...e-in-just-190-days?CMP=Share_AndroidApp_Other

 

[sploo]

It could be a myth, but I thought that one of the reasons why Babbage was unable to build his difference engine was due to the lack of standardised available hardware.

 

[Phil Pascoe]

Get yourself a copy of this - it's excellent.

https://www.google.com/search?gs_ss...CDkyMTFqMGo3qAIIsAIB&sourceid=chrome&ie=UTF-8

 

[RobNichols]

I read the article too. Very interesting.

 

[Fergie 307]

The Americans adopted Whitworth's ideas, not just about threads but measuring in general, very early on.
He was called in as a consultant to the Springfield Armoury, to advise them how to mass manufacture interchangeable parts for their guns. This was a revolutionary concept at the time.
Previously each part was crudely made, and had to be fettled by a skilled armourer to get them to all work correctly. None of the resulting parts of the finished gun could be replaced without similar work.
As a result of Whitworth's input, and machinery supplied by him, they were able to make parts by machine to sufficiently tight tolerances, 0.002 inch of I recall correctly, that they were interchangeable.
So now you could just have boxes full of the various parts for say the trigger mechanism. Unskilled workers could just take one of each and put them together and it would work perfectly. Very much faster, and cheaper.
It also meant that spare parts could be made available that would fit perfectly, something we take entirely for granted now but a ground breaking idea at the time.
The same principle could be applied to anything, watches, cars and not least of course to the manufacture of the machines to make the parts in the first place.
Arguably this was a major reason for American industry taking off as it did, as the inventor of mass production as we know it today.
Typically we spent years arguing about how to adopt these ideas, and so squandered the opportunity it should have given us.

 

[ajs]

It could be a myth, but I thought that one of the reasons why Babbage was unable to build his difference engine was due to the lack of standardised available hardware.

That's what I learned too, as part of the "Introduction to Computing" part of my degree at Manchester over 25 years ago now. If you've ever been to Manchester everything is named after Whitworth - kind of like Harris (mill owner) here in Preston. The story goes early in his career - either in his apprenticeship or not long after - he was tasked with building Babbage's machines.

The difficulties he observed led him to essentially found precision engineering. Firstly the basics, making a precision flat reference surface. Next, an automatic gear tooth cutter to allow for interchangeable gears. Finally of course, the Whitworth screw thread.

 

[Fergie 307]

One of his achievements, which is often forgotten is his contribution to accuracy in measurement. Although Johansson developed Gauge Blocks as we use them today in the 1890's, Whitworth was selling precisely sized reference blocks decades prior to this, and various equipment to accurately measure things.
Being able to make interchangeable parts is only possible if you can specify a tolerance, and have equipment to measure to that tolerance. He pioneered this idea.
In the Crimea the problems were not so much to do with nuts and bolts, but other working parts.
Take the piston in a steam engine in a ship.
If the manufacturer had embraced Whitworth's ideas, then they would know that the piston in the engine measured 8.635 inches for example. They could send you a replacement exactly that size.
A "traditional" maker would have machined the bore in the engine to a nominal size, then made the piston to fit it. Nothing more precise than a set of ordinary calipers and a ruler involved.
The clearance would probably be down to the feel and experience of the machinist.
If the engine had multiple cylinders then they would all be slightly different in size, because they had no way of measuring them accurately.
Need a replacement? All they could do would be to send you a blank, which would then have to be machined to suit the bore when it arrived.

 

[imageel]

I remember in my schooldays so early 60's, visiting the Ford factory at Dagenham since a school colleagues dad was a manager there and I remember watching in amazement parts of the production line in action.
I remember at one point seeing pistons being fitted to engine blocks and if I remember correctly they were marked with either yellow or blue paint and when I asked why it was explained that the machines honing the bores would wear over time and so they had two tolerance limits that they worked to and hence had 2 marginally different sized pistons to achieve an acceptable fit, and before presumably the hones were replaced. It was an amazing experience for me, the scale of the place, the noise, the smells of hot oil and cutting fluids and the overhead gantries and conveyors carrying parts to their respective position on the production line.
The place I really wanted to see was the foundry where they poured the cast iron components however it was a very hot day and our guide said it would be too hot for us!

 

[Chris152]

Fascinating thread.

 

[Fergie 307]

The old days, when the raw materials arrived at the plant and pretty much every part of the car was made on site. Just like the model T.
Very different to how it's done now.

 

[Fergie 307]

Whitworth also designed revolutionary guns. He found the idea of forcing an oversized projectile through rifling to spin it very crude.
His solution was a hexagonal bore, twisted along it's length, and a matching hexagonal projectile. Both more expensive to manufacture, but offset by the advantages. No real friction so the barrels lasted much longer (large guns like those on a battleship might need new barrels after only firing 100 rounds, at vast expense)
Most of the energy of the charge being used to propel the projectile, rather than being wasted in overcoming friction.
Much greater range and penetrating power for a given charge.
In tests his field gun outperformed the conventional competition in every respect, so much so that the test had to be abandoned because it proved impossible to determine the true range of his gun. It was still putting rounds through the target at the maximum distance available, nearly twice the range of the nearest competitor, his great rival Armstrong.
There was quite a scandal at the time when, despite the outcome of the tests, the military contract was awarded to Armstrong, who had some powerful connections in the War Department.
Whitworth guns were used successfully by both sides in the American civil war. Interestingly if you watch the film The Good The Bad and The Ugly, specifically the scene where they get involved in a civil war battle, you will see one of Whitworth's hexagonal barrelled field guns.
Whether this is purely by chance, or someone in the props department had a good knowledge of history I have no idea.
The idea never took off on a large scale, although I have seen reports that H&K have been experimenting with something very similar.

 

[throbscottle]

It could be a myth, but I thought that one of the reasons why Babbage was unable to build his difference engine was due to the lack of standardised available hardware.

It was primarily because he couldn't make the parts to a close enough tolerance. It was made using modern machinery some years ago and works as Charles had planned. It would certainly be interesting to know about the lack of standardised hardware aspect of it though! Must have been so much harder.

 

[Fergie 307]

I am currently working on a long case clock made in 1750. A good example of the issues before machine made fastenings became widely available.
These old clocks do have a handful of screws in the movement, and they can be a nightmare.
They were made by hand using threading plates, essentially a thick slab of hardened steel with threaded holes. You made your blank screw then screwed it into the hole to cut the thread. They came with matching sets of fairly crude taps, or you could make your own using the plate.
The big problem was that with no standard thread sizes at the time manufacturers just made up their own, so thread plates were all different.
The screws that are made in this way are often pretty rough by modern standards, and can easily become damaged or worn to the extent they are no longer usable.
Very often the only answer is to start again and recut the threads to the nearest modern size. You can then make replacement screws that look like the originals, but have the modern standard thread.

Same is true of woodscrews, if you look at old guns, clocks or other items you will often find very clever ways of holding parts together just using pins. Woodscrews where they do appear are entirely handy made.

I once visited a very old church in Spain where they had a collection of relicqaries, some going back to the 11th century. They were mostly made of silver. No screws at all, everything held together by tapered pins and various very ingenious folded joints. The workmanship was quite extraordinary.

 

[Sideways]

The idea never took off on a large scale, although I have seen reports that H&K have been experimenting with something very similar.

Premium German small arms manufacturers Heckler & Koch, and also Austrian Glock, both feature polygonal barrels throughout their ranges of pistols for many years, though sized to match conventional round ammunition. 5, 6 and 8 sided bores according to the model and caliber.
The classic HK P7 pistol was the first of these that I'm aware of.

 

[Fergie 307]

Premium German small arms manufacturers Heckler & Koch, and also Austrian Glock, both feature polygonal barrels throughout their ranges of pistols for many years, though sized to match conventional round ammunition. 5, 6 and 8 sided bores according to the model and caliber.
The classic HK P7 pistol was the first of these that I'm aware of.

Very interesting, I didn't know that. Have to have a look, thank you.