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#51
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F-35's Costs Climb Along With Concerns
"Jack Love" wrote in message ... On Fri, 28 Apr 2006 15:04:23 -0700, (Harry Andreas) wrote: In article , wrote: Note that this is sort of the same approach that lost Germany the war. Everything was hand-finished to very high standards, while us sloppy folks cranked out ten times as many tanks as they could because we let the tolerances be looser and eliminated a lot of the skilled 'touch-labor' in the finishing stages. And we kept a good handle on when 'good enough' was in fact good enough. One of the extreme examples of this was the engine cooling fan on tigers(?) - it was machined out of a single piece of aluminum. - Took lots of precision machining. US tanks had a standard car fan - stamped steel blades riveted to the pulley. - Took 5 stamps, 10 rivets, and mumble mumble machining on the pulley assembly. MUCH cheaper and easier. |
#53
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F-35's Costs Climb Along With Concerns
Paul J. Adam wrote:
Packard cleaned up the castings, milled the mating faces approximately flat (at least, compared to a metal-metal seal) and put a gasket between them. I don't recall hearing tales of P-51s routinely or regularly falling from the skies when their engines failed, nor of the Packard Spitfires being execrated for unreliability (or, for that matter, lack of horsepower). A family friend, now departed, was a wrench-turner on (American) Merlins during the war. He always said the Packard was easier to work on, but did not take damage as well as, the RR version. His reasoning was that, where RR might use (arbitrarily, as I can't recall his exact words) 30 bolts spaced closely to attach an exhaust manifold, Packard would use 20 spaced farther apart. He said that he saw cases where Packard and Rolls-Royce engines would come back with near-identical damage and the genuine article could still produce power. Jeff |
#54
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F-35's Costs Climb Along With Concerns
My father-in-law had a similiar experience here in Canada. In circa
1942 he was an apprentice machinist for a new factory tasked with manufacturing a British 4.5" naval gun design. IIRC, the original British procedure for any shaft/bushing was to machine the shaft with 0.020 in interference and the hand file the shaft to fit. As he said, there wasn't one in a hundred in their labour pool that could do this. Part of his job was developing new dimensions and tolerances to allow parts to be manufactured independently, inspected for dimensions, and then assembled without further machining. |
#55
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F-35's Costs Climb Along With Concerns
"Paul J. Adam" wrote in message ... In message , Ricardo writes Incidentally, a few sources have claimed that the Packard built Merlin, whilst a superb engine, lacked the power levels of the Rolls Royce version. This, it is claimed, was because the British kept secret the composition of the phosphor-bronze bearings that they used in the engine. No, I can't quote a source/s. On the other hand, I heard - from "old factory hands" lecturing on manufacturing technique at Highbury College in 1988 - that a big difference between Packard and Rolls-Royce was in fitting the cylinder head. Rolls-Royce used a precision hand-scraped metal-to-metal fit. Very effective, though extremely demanding in scarce skilled labour. (Attempting to 'file flat' is a useful exercise for a trainee mechanical engineer; it teaches a certain humility in demanding surface finishes) When I started work as an engineering apprentice at ICI they still sealed the main steam joints on the turbines in the power station this way. It isnt the file flat that's so time consuming as the scraping of the surface until its flat according to the reference surface plate. They now use a lapping machine and gasket and its no less reliable and a LOT quicker, plus I doubt there are many fitters around with the skills to scrape joints flat any more. Keith ----== Posted via Newsfeeds.Com - Unlimited-Unrestricted-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- |
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F-35's Costs Climb Along With Concerns
wrote in message ... In article , (DeepSea) wrote: That is interesting - I had no idea that British interest is what gave the P-51 its start. At the time Britain was buying every fighter they could get their hands on, including the Brewster Buffalo. British and French purchasing gave a major boost to the US aircraft industry. The first production orders for the Airacobra were from France. Ken Young The first use of the Grumman Wildcat in combat was by the Fleet Air Arm of the RN Keith ----== Posted via Newsfeeds.Com - Unlimited-Unrestricted-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- |
#57
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F-35's Costs Climb Along With Concerns
"Harry Andreas" wrote in message ... In article , wrote: Note that this is sort of the same approach that lost Germany the war. Everything was hand-finished to very high standards, while us sloppy folks cranked out ten times as many tanks as they could because we let the tolerances be looser and eliminated a lot of the skilled 'touch-labor' in the finishing stages. Hmmm. I wouldn't ride that horse too far. Ever see a 1944 built Walther P-38, or Waffenfabrik Mauser? They didn't spend nearly any time finishing them as compared to the early war versions. The German record was very mixed They certainly become very efficient at manufacturing light weapons, the MG-42 was a classic design that was simple , reliable and excellent. Trouble is they also made plenty of monstrously complex weapons systems. The Panther and Tiger tanks were examples of technically advanced weapons that simply couldnt be cranked out in the numbers needed due to the complexity of their manufacture. "US folk" cranked out so much hardware because there were more of us, we had more natural resources at hand, and we weren't being bombed. Trouble is even Britain outproduced Germany for much of the war with fewer natural resources and we WERE being bombed. Bombing didnt seriously disrupt the German manufacture of weapons until mid 1943 by which time the tide of war had turned. The allies decided in many cases to accept technically inferior weapons if they could be more easily mass produced Compare Battle tank production in 1943 Germany 3,000 Mk 4, 3,800 Panthers, 650 Tigers USA 21,000 M4 Sherman Keith ----== Posted via Newsfeeds.Com - Unlimited-Unrestricted-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- |
#58
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F-35's Costs Climb Along With Concerns
In article , "Keith W"
wrote: "Harry Andreas" wrote in message ... In article , wrote: Note that this is sort of the same approach that lost Germany the war. Everything was hand-finished to very high standards, while us sloppy folks cranked out ten times as many tanks as they could because we let the tolerances be looser and eliminated a lot of the skilled 'touch-labor' in the finishing stages. Hmmm. I wouldn't ride that horse too far. Ever see a 1944 built Walther P-38, or Waffenfabrik Mauser? They didn't spend nearly any time finishing them as compared to the early war versions. The German record was very mixed Keith, I hear ya, and the other posters who have said similar things, but I still object to Mr McCall's statement that, in Germany, "Everything was hand-finished to very high standards". That's just not true. As you point out, it was very selective, and as I pointed out, there are definite examples of German industry reducing their quality standards to meet production demands. cheers PS: now that the Hobbit's (Rooney) out, what will England do? -- Harry Andreas Engineering raconteur |
#59
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F-35's Costs Climb Along With Concerns
Harry Andreas wrote: PS: now that the Hobbit's (Rooney) out, what will England do? Try and win some football without a spoilt brat throwing tantrums on the pitch and verbally abusing the match officials when, rightly, he is called to task. |
#60
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F-35's Costs Climb Along With Concerns
In article , Ricardo
wrote: Harry Andreas wrote: PS: now that the Hobbit's (Rooney) out, what will England do? Try and win some football without a spoilt brat throwing tantrums on the pitch and verbally abusing the match officials when, rightly, he is called to task. LOL! Well, Ashley Cole looked all right today anyway. -- Harry Andreas Engineering raconteur |
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