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    Re: Problem with a sextant
    From: Bill B
    Date: 2006 Apr 26, 15:47 -0500

    > Bill,
    > Thanks.
    > Neither do I understand what Joel really proposes
    > to measure.
    >
    > Alex
    
    If I understand Joel, what this setup would measure is distance from the arc
    to the pivot point.
    
    
    I believe he suggests securing the sextant's arm and placing the dial
    indicator against the arc and moving the frame through its range of motion.
    If not uniform it may be off on one or all of:
    
    1. The arc is not a perfect arc of a circle
    2. The axis of rotation is off in relation to the arc
    3  The bearings on the arm are eccentric.
    
    It would be impossible to tell which with this setup IMHO, but would point
    out a problem.
    
    If one could measure the distance from the precise axis of rotation to
    various points along the arc one could narrow down the list of suspects.
    
    If I read you correctly, you wish to measure the distance between teeth on
    the arc. I do not believe the above setup, as I understand it, will
    accomplish that for you.
    
    Bill
    
    
    

       
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