brass vs bronze for making a punch

Oh,'re a Canadian. They had to put facets on your nickels to keep you from shaving them on those long winter nights.
Reply to
Ed Huntress
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Good Lord! Fifty years ago? I can just barely remember the incident, the details are gone for ever :-)
>> >>They also had a "tape controlled" machine there that would do things >>automatically. It could even change tools, or so I was told. One guy >>had been to school on the control system but it was never used while I >>was there. >> >>I did ask the guy how it worked and it used a punched tape like a >>telex machine. The left column was, say longitudinal travel, and one >>punch was one increment of movement. > >Um...that's how I learned lathe programming. We had a Sheldon 1710H >controlled by a Bendix 5 NC, and a teletypewriter to key in and punch >the paper tape. I could program straight cylinders and tapers, and >face them off, IIRC. I never did any actual work with it; the real >machinists wanted to play with it and hogged the keyboard. > >For anything complex, we used a telephone-connected time-sharing >system that did the programming by computer.
Reply to
John B.
At another base one of the guys tried turning coin sized blanks for the Coke Machine. It didn't work either but somehow one of the machined blanks got stuck in the machine and the Coke Machine Guy went to the Squadron Commander and a great investigation ensued... "My guy made a fake coin" Nah, couldn't be, none of them drink Coke".
But it did appear that a Coke machine was a bit "smarter then the average bear", to paraphrase Pooh.
A far better scheme was discovered by "one of the guys" while TDY to Okinawa to support the "Black Birds". In wandering around he discovered that the Jet Engine Shop had bins of some sort of "bronze" nuts that could be bored out to finger size and when machined and polished a bit looked surprisingly like a gold ring. Subsequently he discovered that the "ladies" in the pubs would trade their services for gold rings.
He said that if he had any more spare time to make rings he probably would have "died in a foreign land" :-)
Reply to
John B.
Depends. Back as late as the 1970s, I would commonly see the term "mil" used in integrated circuit data sheets -- for things like the spacing between pins on a given side (typically 100 mils), and the separation between two rows of pins (for common TTL ICs, typically 300 mils -- though some were larger, 400 mils, 600 mils and such). The same units were used for the dimensions of the bodies of the chips, between the pins, too. So, the term stuck around for a while longer in certain industries.
Now -- the surface mount chips -- with rows of ribbon leads soldered to a single surface of the board were 50 mil centers back then, though smaller now, I believe.
I don't have any recent data sheets ready to hand, so they may have changed since then.
Enjoy, DoN.
Reply to
DoN. Nichols
Coming from Semi on the last three jobs - 10 years ago ...
The BGA ball grid arrays were metric. And some of the other Modern forms of surface mount.
Science and Engineering was metric all along, just took some time for the general industry to go that way.
The older stuff was designed by Fairchild and TI and later EIA and JEDEC who created specks on the actual leadframe and therefore pinouts. Yes RCA and Harris and ..... created stuff as they needed and were all brought in to have common pinouts, form and function. Competition was not part of the scene, we were design engineers and loved our jobs.
I was a EIA/JEDEC member Specs or 4 companies, DRAMS, SD, DD, DIMM SoDIM SIM and Sram and packaging and motherboards. I was a busy guy in a week or two during JEDEC meetings.
JEDEC was the old name but the group went International in nature.
It was nice, I had friends in dozen or more companies. We all assigned each other tasks to get done to complete specifications on this or that.
Reply to
Martin Eastburn

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