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: Sextant frame design- Who won?
    From: Thomas Rick
    Date: 2021 Nov 8, 04:56 -0800

    Bill- I have an interest in the thermal stability question for frame arrangement.

    I note this paper though behind the pay wall provides notes on tested results for sextant material design:

    I have a particular interest in how the ladder frame re- C Plath compares to the circular C&P as both are arived at early and long held designs. I would like to see empirical data of arc displacement for each design over a range of temperatures. I also have a specific interest in the C Plath "Traditional" as it was a late adoption which copies but seems to fall short in particulars of a center circle design as manufacuted by C&P. We now have regenerative design capabilities in even modest CAD software- I wonder at the frame arrangemnt which this process would arrive at given constraints such as frame material and arc displacement. Perhaps in my ignorance I am missing the key attribute of thermal change which might be variable index error not arc displacement? 

    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