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    Re: DIY Davis prism directly on the mirror?
    From: Brad Morris
    Date: 2018 Nov 8, 22:31 -0500
    Tony

    I can think of one reason why not.

    Suppose you do not manage to get the orientation correct, or select the wrong prism, or any other of features that may affect function.  Suppose, in the end, you don't like the prism functionality and wish to go back to a swung sextant

    How will you back this change out?

    Brad 

    On Thu, Nov 8, 2018, 10:40 AM Tony Oz <NoReply_TonyOz@fer3.com wrote:

    Dear Brad,

    This is a sketch of where I'd like to glue a prism. Its' edge where the two faces meet should be made parallel to the transparent|mirrored boundary.

    Most sextants I saw so far let the horizontal mirror to rotate slightly in the holder, at least my SNO-T does. So I will definitely need to adjust the mirror+prism position (within ~half degree) using the cross tool - just as the original Davis prism attachment was supposed to be properly aligned. And later on - to re-check the alignment with the same cross tool.

    Actually my question was if there is a reason to NOT have a prism permanently attached (glued) on the horizon mirror. You ask why? - I think it is a convenience and more robust/compact design.

    And I want this prism there exactly for its' indended purpose - to help to align my sextant vertically at sea.

    Please comment.

    Warm regards,

    Tony

    60°N 30°E


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