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A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
C&P Index Arm Adjustment
From: Greg Rudzinski
Date: 2016 Apr 24, 18:45 -0700
From: Greg Rudzinski
Date: 2016 Apr 24, 18:45 -0700
My weather beaten Cassens & Plath started to show a great deal of side error for no good reason so the index arm was set to zero then wiggled as I looked through the x4 scope. Side error was seen drifting all over because of a loose index arm riding against the arc. The fix was to tighten up a pair of set pins above the micrometer worm gear that had worked loose over time.
1-remove plastic micrometer cover on lower index arm (4 screws).
2- loosen pin lock nuts (see image).
3- screw down pins until just touching arc.
4- screw down lock nut.
5- install plastic cover.
6- adjust out side error.
There should now be no wiggle in the index arm through the arc.
Greg Rudzinski
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