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    Re: Borrowed Bygrave
    From: Brad Morris
    Date: 2016 Jan 15, 02:36 -0500


    One other point

    Robin Stuart requested that I precisely survey my MHR1 for all scale markings.  I complied and he created software that will generate precise copies!!!   So you get the identical markings.

    Robin and I agreed that the original German artwork must have been hand drawn very carefully and then photo reproduced.  Of course, Robin's software will allow you to size directly for your tubes

    If you want authenticity, that's the way to go.

    I'd suggest Francis Upchurch for putting the scale on the tube.  He's done it a few times now and may have some tips.  Alignment is pretty important


    On Jan 15, 2016 2:28 AM, "Brad Morris" <bradley.r.morris@gmail.com> wrote:


    How lucky!!!

    As to your reproduction, back some years ago, a fellow in Germany (?) produced a set of mechanical drawings and even offered up the cardboard tubes that are used.  I'm hoping he's still on list.  That would be ideal, as he offered the tubes and plans.

    I still have my un-used tubes (maunly because I have an MHR1 and have little need of a repro).  If that individual is sold out of the proper tubes, we can work something out...  I don't want to undercut or otherwise fiddle with his good works, so he goes first!!

    Gary has made several reproductions, and they are quite enviable. 


    On Jan 14, 2016 8:17 PM, "David Pike" <NoReply_DavidPike@fer3.com> wrote:

    I’ve got the loan of a Bygrave Position Slide Rule MkIIA from the Royal Institute of Navigation for a couple of months (photos below).  Apparently, they had two, a good one and a poor one.  Unfortunately, I was only able to find the poor one; nobody seemed to know what happened to the good one.  It carries the inscription that it was produced by the Air Ministry Laboratory South Kensington in August 1920.  If the number was ever filled in, it’s long since rubbed off.  I’d like to teach myself to use it prior to possibly making a copy for myself with plastic piping.  Is the best set of usage instructions those on Gary’s Freddie Noonan page?  Also, does anyone know where I can find a photo or print out of the explanation off the side of the MkIIA?  Finally, does anybody know what went down the inside of the cylinders?  All I can see is the remains of a brass chain.  DaveP

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