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    Re: Cylindrical Slide Rule tube poll
    From: Hanno Ix
    Date: 2010 Jan 22, 09:11 -0800

    As I said in this group, I am on the list of interested people. 

    Actually, for now I really do not care what materials are being used.
    I just would like to get to use a working Bygrave for a while before I make suggestions for modifications if any.



    From: Gary LaPook <glapook@pacbell.net>
    To: NavList@fer3.com
    Sent: Thu, January 21, 2010 11:09:29 PM
    Subject: [NavList] Re: Cylindrical Slide Rule tube poll

    Remember to allow for the thickness of the paper carrying the cotangent scale and the plastic covering it in figuring the clearance between the tubes and so the proper sizes for the tubes. Measuring the scale on my first reproduction of the Bygrave it is 1.516 ~1.520 inches in diameter mounted on  a 1.500 inch tube so the scale takes up about .020 inches of clearance between the tubes, about .5 mm.


    Wolfgang Hasper wrote:
    > Since we come back to the tubes time after time
    > I am interested to find out how many would like to make an actual reproduction on reproduced tubes?
    > The HR1 uses Aluminium tubes
    > (all dimensions [mm])
    > inner tube    54x1        235 long
    > interm. tube    58x1        225 long
    > outer tube    62x1        222 long
    > A kit of all three sizes 300 long each would be nice.
    > Narrow tolerances are required for the outer diameters to fit the scales, the inner diameter is less important. If there is a felt lining as on the original you can easily compensate for 0.2 mm.
    > Aluminium as the material seems preferable but not compulsory. I would not like to have stainless steel, it is heavy and a pain to machine.
    > To investigate the local possibilities for custom tubes I have started with a firm that works with perspex. Maybe plastic is more realistic to have in custom dimension than aluminium? We'll see.
    > I will try on aluminium tubes also.
    > If Douglas is successful earlier it will be even better, maybe we can get two independent quotes.
    > How many on the list would be interested in how many kits?
    > If you want I could compile a list of all interested so we know how many metres we will have to order ;o)
    > Wolfgang

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