NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Alan S
Date: 2013 Sep 6, 16:35 -0700
All:
I have a "home made" mirror type artificial horizon, composed of the following. The mirror is 10" x 10", and is, at least supposedly, that "first surface mirror"
Said mirror is mounted on 3/4" thk. x 14.5" x 11.75" piece of plywood, the mirror held in place with masking tape strips in each corner. It appears secure so mounted.
The assembly has 3 1/4" x 20 tpi leveling screws in "t" nuts, the screws are round headed machine bolts, heads down.
I understand that leveling of a mirror horizon is critical. I use an Empire brand 9" long torpedo level, the maker claims is accurate to within .0005"/",would this be sufficiently accurate for leveling of the mirror assembly? I also use a Davis Artificial Horizon, filled with water, which which I get quite good results, my calculated fix is often inside 2 NM of a known position (GPS coordinates).
Trying sun shots this AM, with the mirror assembly, after leveling, the sun appeared painfully bright, even with ALL sextant sun shades in. Seems like additional sun shields would be appropriate, but what sort and how to rig them? As memory serves, a dark film was, at one point, mentioned by a poster here, don't recall who. Do you think that a cardboard tent spanning the mirror, with blue and orange colored film shields might work. Colored plastic shields that were furnished with the Davis Artificial Horizon work quite well.
Any guidance would be appreciated. Thanks
Alan
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