NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Home made artificial horizon
From: Geoffrey Kolbe
Date: 2011 Oct 04, 18:37 +0100
From: Geoffrey Kolbe
Date: 2011 Oct 04, 18:37 +0100
Robert wrote:
No no, you don't understand Robert. There is a satisfaction in the process of spending a great deal of time and effort to build an AH as cheaply as possible using plastic, string and sealing wax. ;-)
But on the matter of practicality, I have no doubt that you are correct. Could you take the plastic string and sealing wax AH to navigate your sledge to the middle of the Antarctic? Or your camel to the middle of the Sahara desert? Possibly, but people have certainly been there and done that with a Freiberger AH. I took the short cut many years ago and bought one.
One note on the use of levels. Just because the graduation on the level is only one mil say, (about 3 MOA), does not mean that you are limited to an accuracy of 1 mil in level adjustment. By turning the level end for end for comparison and estimating the bubble position to one tenth of a graduation, it is possible to get an accuracy in level-ness at least an order of magnitude better than the level graduations would suggest.
Geoffrey Kolbe
I can't take it anymore!
Seems like you folks are going to a great deal of hassle and looking in every hidden corner for the perfect levelling mechanism and/or to make an effective artificial horizon. Short of using a pan of motor oil or getting hold of some mercury, the best option is, in my opinion, to just go out and purchase a Freiberger artificial horizon which comes with all you need to obtain pinpoint accuracy (as much as is possible with a sextant).
No no, you don't understand Robert. There is a satisfaction in the process of spending a great deal of time and effort to build an AH as cheaply as possible using plastic, string and sealing wax. ;-)
But on the matter of practicality, I have no doubt that you are correct. Could you take the plastic string and sealing wax AH to navigate your sledge to the middle of the Antarctic? Or your camel to the middle of the Sahara desert? Possibly, but people have certainly been there and done that with a Freiberger AH. I took the short cut many years ago and bought one.
One note on the use of levels. Just because the graduation on the level is only one mil say, (about 3 MOA), does not mean that you are limited to an accuracy of 1 mil in level adjustment. By turning the level end for end for comparison and estimating the bubble position to one tenth of a graduation, it is possible to get an accuracy in level-ness at least an order of magnitude better than the level graduations would suggest.
Geoffrey Kolbe
