Welcome to the NavList Message Boards.

NavList:

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

Compose Your Message

Message:αβγ
Message:abc
Add Images & Files
    or...
       
    Reply
    Re: Traditional navigation by slide rule
    From: Paul Dolkas
    Date: 2016 Oct 20, 10:11 -0700

    Bob-

     

    After looking at the printout of the slide rule, I have to say that converting it to a 3-D model is quite possible, but a hell of a lot of work. There’s hundreds of marks that would have to be accurately measured and manually entered into the model, one by one. Even if you have a dxf file, where the marks are already in a 2-D cad format, translating them into a 3-D format would keep me busy for a long time.

     

    The best way, I think, is to give the file to a engraver that can work directly from the file, if that’s possible. I was impressed with the custom ruler somebody posted – it’s super precise, and the PCB material it’s printed on is pretty robust stuff.

     

    Having said that, using 3-D printing to make the sliding parts themselves (that the scales could be glued onto) would be a trivial thing.

     

    Paul Dolkas

     

    From: NavList@fer3.com [mailto:NavList@fer3.com] On Behalf Of Tony Oz
    Sent: Thursday, October 20, 2016 7:29 AM
    To: paul{at}dolkas.net
    Subject: [NavList] Re: Traditional navigation by slide rule

     

    Dear Bob,

    Are you sure the 3D-printing is really necessary?

    I think a much simpler and cheaper way exists.

    Consider a backplane to which a pair of spacers are glued, a movable spacer for the slider's scale and the three scales glued to the relevant spacers. The key idea is to arrange the stator's scales to be wider than the movable spacer so that they (the static scales) overhang that spacer preventing its' falling out.

    The (rather simplistic) sketch is attached.

    All this make it possible to rely on laser engravement of the scales - I'm sure a much more precise process. The wide enought gap between the spacers - provided that the scales themselves are tightly pressed together by their edges - make glueing everything easier, just make sure the scales' indexes are aligned properly. One does not need to worry about the parallelism of the spacers, etc.

    Two-layer white-cover/black-substrate plastics exist of wide list of vendors.

    So an inexpensive DIY kit of the three scales and a backplane (with usage instructions engaved) is quite possible.

    Regards,

    Tony



    Attached File:
    Image removed by sender.
    Image removed by sender.

    View and reply to this message

    File:


       
    Reply
    Browse Files

    Drop Files

    NavList

    What is NavList?

    Join NavList

    Name:
    (please, no nicknames or handles)
    Email:
    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:

    Email Settings

    Posting Code:

    Custom Index

    Subject:
    Author:
    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