NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Sextants and Glue [was Sisteco Prismatic Compass]
From: Fred Hebard
Date: 2004 Mar 20, 08:56 -0500
From: Fred Hebard
Date: 2004 Mar 20, 08:56 -0500
Jared, I believe my sextant is the C&P Professional Sextant, as referred to on their website. However, I am not familiar with older designs. It has 3 horizon and 4 index filters plus an astigmatizer added to the the index filter rack. There is no added button on the micrometer dial for adjusting for dip and index error. The mirror housings are aluminum, as best as I can tell. Most lens systems I have disassembled glued the compound lenses together, but mounted them with threaded rings in the barrel. Retaining clips also could be used for filters. If it's so easy to replace, do you know how I might dissolve the old glue clinging to the two horizon filters that have fallen out and what sort of glue I should use to replace them? Fred On Mar 19, 2004, at 8:02 PM, Jared Sherman wrote: > Fred, I would bear in mind that most of the finest camera lenses in the > world today are in fact built up from multiple elements--glued > together. > Glue is literally the stuff that makes precision optics possible today. > > If the alignment and material selection is done properly, the glue > joint is > stronger, lighter, and thinner than screwed metal rings. It will never > seize > up, and it is easily replaced when and if need be. > > There are also combat aircraft whose wings are literally glued on. > Glue is > not necessarily a bad thing! And if it happens to keep down the cost > of the > sextant, even better. > > Which sextant did you get? How big is the filter rack on it? (How many > filters?) >