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Re: [woodandbrass] W&B Exam. Paper One. Flanges.

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  • marenfred
     None of the flanges fit. Like the flanges, the man has a screw loose. He is probably a Phalangist. His name? - Bezel bub. Fred On Sep 4, 2008, at 11:49:06
    Message 1 of 7 , Sep 4, 2008
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       None of the flanges fit. Like the flanges, the man has a screw loose. He is probably a Phalangist. His name? - Bezel bub.
      Fred
      On Sep 4, 2008, at 11:49:06 AM, "eric evans" <ericevans@...> wrote:
      From:"eric evans" <ericevans@...>
      Subject:[woodandbrass] W&B Exam. Paper One. Flanges.
      Date:September 4, 2008 11:49:06 AM EDT
      To:woodandbrass@yahoogroups.com

      A man has ten lenses. Each lens needs a flange to make it usable. The
      man goes on e bay and pays a very high price for twelve flanges. He
      tries each of his ten lenses with each of his twelve flanges. Using
      Sod's 2nd. variant of Murphy's Law, estimate:
      a. How many of the flanges fit a lens?
      b. What is the name of the man?
      Marks will be awarded for tear-stained papers.
      Eric.



    • eric evans
      Hi Milan, Your exam results are now available and are posted in another place. Seriously, not being much given to deep thought, I had never previously
      Message 2 of 7 , Sep 5, 2008
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        Hi Milan,
        Your exam results are now available and are posted in
        another place.
        Seriously, not being much given to deep thought, I had never
        previously considered how the larger flanges might have come into
        being, except to look at them and think wow, that must have been a
        hell of a size of bar stock, a huge chuck and an enormous amount cut
        to waste. I will look at them a bit more closely in future for the
        casting marks, which of course is a much better way of doing it, once
        someone has pointed it out.
        Eric.


        --- In woodandbrass@yahoogroups.com, "Milan Zahorcak"
        <milan.zahorcak@...> wrote:
        >
        > Oh, Eric . . . tsk, tsk.
        >
        > You can always tell who are the professional lens collectors, and
        those who
        > are still the optimistic novices, by their outlook on flanges.
        >
        > There is a Fundamental Axiom in lens collecting concerning
        flanges. It goes
        > like this - write this somewhere in plain view:
        >
        > Flanges only come in three forms:
        >
        > 1. Too small
        >
        > 2. Too large
        >
        > 3. Wrong thread pitch.
        >
        > I have a collection of flanges that DRAWFS my collection of lenses -
        easily
        > 10x. The reason is, of course, because none of them fit anything
        that I
        > own.
        >
        > I have an engineering background, and own precise laboratory grade
        digital
        > micrometers, accurate to .01mm, .0005" and pitch gauges that cover
        every
        > thread ever made from 90 tpi to 12 tpi - yes, including metric and
        > half-sizes.
        >
        > And when I need my superb machinist to make a flange for me - do
        you think
        > that I can provide him with a the appropriate dimensions via email,
        have him
        > make the flange, and believe for even a moment that there is the
        remotest
        > chance of the new flange fitting my lens?
        >
        > There is a very long answer that involves thoughtful and complex
        profanity
        > in several Eastern European languages, lapsing into outraged
        swearing in
        > tongues . . . but in short, no.
        >
        > I have to send him the lens, he takes the basic measurements, gets
        very,
        > very close, and then fits the one to the other - usually just
        making minute
        > corrections to the flange to preserve the sanctity of the lens -
        but he'll
        > "chase" the lens threads if there is damage or roughness.
        >
        > Live and learn, live and learn . . .
        >
        > mz
        >
        > PS: By the way, were you aware that the vast majority of older
        flanges and
        > some of the more complicated hoods (flared Globe hoods, for
        example) were
        > sand cast and then finished on a lathe? As opposed to be being
        turned on a
        > lathe from an existing piece of stock? On the under side of many
        flanges
        > you can still see the grain of the mold.
        >
        > Also true for the majority of knobs, larger gears, etc.
        >
        >
        >
        > -----Original Message-----
        > From: woodandbrass@yahoogroups.com
        [mailto:woodandbrass@yahoogroups.com] On
        > Behalf Of eric evans
        > Sent: Thursday, September 04, 2008 8:49 AM
        > To: woodandbrass@yahoogroups.com
        > Subject: [woodandbrass] W&B Exam. Paper One. Flanges.
        >
        >
        >
        > A man has ten lenses. Each lens needs a flange to make it usable.
        The
        > man goes on e bay and pays a very high price for twelve flanges. He
        > tries each of his ten lenses with each of his twelve flanges. Using
        > Sod's 2nd. variant of Murphy's Law, estimate:
        > a. How many of the flanges fit a lens?
        > b. What is the name of the man?
        > Marks will be awarded for tear-stained papers.
        > Eric.
        >
      • Milan Zahorcak
        Cast marks . . . yes, casting is a simple way to replicate complex parts, at least to within a certain tolerance that can then be appropriately finished. I
        Message 3 of 7 , Sep 5, 2008
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          Message
          Cast marks . . . yes, casting is a simple way to replicate complex parts, at least to within a certain tolerance that can then be appropriately finished.  I first started noticing cast marks when looking closely at the hoods on Globe lenses.  Many hoods appeared to have slight flaws in their fine details - and at near microscopic magnification, the reason why became apparent.  See the attachment.
           
          Interesting enough - in certain high ticket items - certain flaws in a master mold form show up for years in the final product and can help to identify an original from a fake.  But now I come close to poaching on someone else's preserve.  However, it is a interesting note, and if the other member is willing to share the details, it makes for a fascinating story.  Other member ???
           
          Regards,
           
          mz
           
           
           
           
           
           
          -----Original Message-----
          From: woodandbrass@yahoogroups.com [mailto:woodandbrass@yahoogroups.com] On Behalf Of eric evans
          Sent: Friday, September 05, 2008 5:03 AM
          To: woodandbrass@yahoogroups.com
          Subject: [woodandbrass] Re: W&B Exam. Paper One. Flanges.

          Hi Milan,
          Your exam results are now available and are posted in
          another place.
          Seriously, not being much given to deep thought, I had never
          previously considered how the larger flanges might have come into
          being, except to look at them and think wow, that must have been a
          hell of a size of bar stock, a huge chuck and an enormous amount cut
          to waste. I will look at them a bit more closely in future for the
          casting marks, which of course is a much better way of doing it, once
          someone has pointed it out.
          Eric.

          --- In woodandbrass@ yahoogroups. com, "Milan Zahorcak"
          <milan.zahorcak@ ...> wrote:
          >
          > Oh, Eric . . . tsk, tsk.
          >
          > You can always tell who are the professional lens collectors, and
          those who
          > are still the optimistic novices, by their outlook on flanges.
          >
          > There is a Fundamental Axiom in lens collecting concerning
          flanges. It goes
          > like this - write this somewhere in plain view:
          >
          > Flanges only come in three forms:
          >
          > 1. Too small
          >
          > 2. Too large
          >
          > 3. Wrong thread pitch.
          >
          > I have a collection of flanges that DRAWFS my collection of lenses -
          easily
          > 10x. The reason is, of course, because none of them fit anything
          that I
          > own.
          >
          > I have an engineering background, and own precise laboratory grade
          digital
          > micrometers, accurate to .01mm, .0005" and pitch gauges that cover
          every
          > thread ever made from 90 tpi to 12 tpi - yes, including metric and
          > half-sizes.
          >
          > And when I need my superb machinist to make a flange for me - do
          you think
          > that I can provide him with a the appropriate dimensions via email,
          have him
          > make the flange, and believe for even a moment that there is the
          remotest
          > chance of the new flange fitting my lens?
          >
          > There is a very long answer that involves thoughtful and complex
          profanity
          > in several Eastern European languages, lapsing into outraged
          swearing in
          > tongues . . . but in short, no.
          >
          > I have to send him the lens, he takes the basic measurements, gets
          very,
          > very close, and then fits the one to the other - usually just
          making minute
          > corrections to the flange to preserve the sanctity of the lens -
          but he'll
          > "chase" the lens threads if there is damage or roughness.
          >
          > Live and learn, live and learn . . .
          >
          > mz
          >
          > PS: By the way, were you aware that the vast majority of older
          flanges and
          > some of the more complicated hoods (flared Globe hoods, for
          example) were
          > sand cast and then finished on a lathe? As opposed to be being
          turned on a
          > lathe from an existing piece of stock? On the under side of many
          flanges
          > you can still see the grain of the mold.
          >
          > Also true for the majority of knobs, larger gears, etc.
          >
          >
          >
          > -----Original Message-----
          > From: woodandbrass@ yahoogroups. com
          [mailto:woodandbrass@ yahoogroups. com] On
          > Behalf Of eric evans
          > Sent: Thursday, September 04, 2008 8:49 AM
          > To: woodandbrass@ yahoogroups. com
          > Subject: [woodandbrass] W&B Exam. Paper One. Flanges.
          >
          >
          >
          > A man has ten lenses. Each lens needs a flange to make it usable.
          The
          > man goes on e bay and pays a very high price for twelve flanges. He
          > tries each of his ten lenses with each of his twelve flanges. Using
          > Sod's 2nd. variant of Murphy's Law, estimate:
          > a. How many of the flanges fit a lens?
          > b. What is the name of the man?
          > Marks will be awarded for tear-stained papers.
          > Eric.
          >

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