NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Wolfgang Hasper
Date: 2011 Mar 31, 11:38 -0700
Some time ago I made a horizon mirror sin only relatively simple tools:
A drill press, two sizes of hole saws, drills, tapping equipment
The mirror cell follows te Freiberger mirror in dimensions
~ 125 mm dia over all
100 mm dia mirror
I used hole saws of 105 mm and 127 mm to cut ot a circular base and a ring from 5 mm aluminim, srewed togerther with M3 brass screws
3 more brass screws with tpped ends are uses for levelling. M3 has sufficiently fine pitch.
The mirror bears on 3 steel balls ~ 4 mm dia from a ball bearing and is held in place by another 3 opposing smaller balls in simple plastic springs.
The mirror cost around 25 €, the rest next to nothing, ~ 6 hors of work.
You only need a good grade spirit level, considerably more expensive and small & light enogh to fit onto the mirror.
c.f. linked photos
regards
Wolfgang
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