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: Celestaire Astra IIIB backlash
    From: Douglas Stephen
    Date: 2020 Jun 15, 06:01 -0700

    Thanks for the response, there is no obvious play in the micrometer knob. All the screws are tight. I took off the cover on the micrometer knob and tightened the scew that attaches it to the gear shaft as much as I was comfortable with (it bears down on plastic in the knob). I even tried pressing with a finger agains the gear to press it more firmly into the rack while turning the micrometer both ways - still the same amount of backlash. I did the same with pressing against the end load spring while checking for backlash - same result. The micrometer feels like the same resistance the first 2 minutes as the rest, although the micrometer seems to have a bit more resistance in one direction that the other - mostly around 0 degrees. I even measured some star distances so I wasn't just checking backlash at near 0 degrees, same results. I think what I need to do is just appreciate that I can get good readings with careful operation of the sextant and try to understand that there are some things I just don't understand (like where this backlash is coming from).



    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