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A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Sextant mirror stability
From: Bruce Stark
Date: 2004 Oct 14, 13:39 EDT
From: Bruce Stark
Date: 2004 Oct 14, 13:39 EDT
Fred,
You wrote: "I haven't studied the following experimentally, but it seems to me that sextant mirrors take a while to "settle down" after they are removed for cleaning, etc. It also seems better not to adjust them if there is no side error or failure of index mirror perpendicularity, as long as the index error is a reasonably small number, such as under one or two minutes of arc. "The Sextant handbook" also cautions against over-adjustment. I wonder what other's feelings, experience, etc., are about this."
On the rare occasion I adjust a mirror, I finish by giving the mirror frame a few taps with the back of a fingernail. Perhaps there's no point in it, but it can't hurt.
Bruce
You wrote: "I haven't studied the following experimentally, but it seems to me that sextant mirrors take a while to "settle down" after they are removed for cleaning, etc. It also seems better not to adjust them if there is no side error or failure of index mirror perpendicularity, as long as the index error is a reasonably small number, such as under one or two minutes of arc. "The Sextant handbook" also cautions against over-adjustment. I wonder what other's feelings, experience, etc., are about this."
On the rare occasion I adjust a mirror, I finish by giving the mirror frame a few taps with the back of a fingernail. Perhaps there's no point in it, but it can't hurt.
Bruce
