Loading ...
Sorry, an error occurred while loading the content.

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

Expand Messages
  • Milan Zahorcak
    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
    Message 1 of 7 , Sep 4, 2008
    • 0 Attachment
      Message
      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.

    • 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 2 of 7 , Sep 4, 2008
      • 0 Attachment
         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 3 of 7 , Sep 5, 2008
        • 0 Attachment
          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 4 of 7 , Sep 5, 2008
          • 0 Attachment
            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.
            >

          Your message has been successfully submitted and would be delivered to recipients shortly.