Welcome to the NavList Message Boards.


A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding

Compose Your Message

Add Images & Files
    Re: Cylindrical Slide Rule tube poll
    From: Gary LaPook
    Date: 2010 Jan 24, 12:35 -0800
    Since you are using a 50 mm tube it should be possible for you to use the two in plug to make a locking mechanism, see http://www.fer3.com/arc/m2.aspx?i=111582


    Hein Bodahl wrote:
    On 23.01.2010 06:56, Gary LaPook wrote:
    You guys appear to be trying to achieve perfection. The original Bygrave
    and my copy both achieve the same level of accuracy, one or two minutes
    of arc, even though my tube is only 1.5 inches in diameter. I just cut
    and tried different percentage settings for my printer until I got a
    reasonable fit and it works as well as the original. It's not worth
    pulling your hair out to try to get better accuracy.
    What hair I have left is hardly worth pulling out for any reason :)
    I am using my sextant in an armchair 100 miles from the nearest natural
    This is a wonderful, educational hobby for me. As such, nitpicking time
    consumption is essential. If someone else also can benefit from it, all
    the better.
    After some consideration and testing, 50mm (2") seems to do the trick
    for me. 50mm  will keep the entire cot scale divided down to at least 1'
    on a 35cm (14") long tube. It may not be necessary but I think it looks
    I have attached the prototype scales, one continuous cos-cot for A3
    sheets to save a little on tube length, and separate cot and cos scales
    for A4 sheets in case somebody with an A4 printer wants to try.
    As some of the labels will be cut of on the right side I have extended
    the scales on the left side. They are intended to be cut vertically
    exactly where the scales start at the bottom (digitally if you want to

    Browse Files

    Drop Files


    What is NavList?

    Join NavList

    (please, no nicknames or handles)
    Do you want to receive all group messages by email?
    Yes No

    You can also join by posting. Your first on-topic post automatically makes you a member.

    Posting Code

    Enter the email address associated with your NavList messages. Your posting code will be emailed to you immediately.

    Email Settings

    Posting Code:

    Custom Index

    Start date: (yyyymm dd)
    End date: (yyyymm dd)

    Visit this site
    Visit this site
    Visit this site
    Visit this site
    Visit this site
    Visit this site