A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Tibor Miseta
Date: 2021 Mar 2, 12:52 -0800
Not beeing allowed to travel I played a bit with the idea of constructing a DIY starfinder. The intention was to educate myself and understand things better, but finally it became a usable backyard navigator's tool, I think.
Hope it could help the newcomers like me, better understand the motion of celestial bodies and learn the sky.
I collected all valuable information that I could found here on Navlist, descriptions by Ed Popko and recomended modifications by Gary Lapook, Frank Reed, Greg Rudzinski and others, and tried to incorporate them (or at least what I could understand from them).
My design is unusal in the way that the alt-az grid is the stator and the star wheel is the rotor. This is because the rotor is intended to be printed on transparency film, that are usually 100 microns thick only, and I think it would be too vulnerable to make it dismountable. So the rotating star wheel must be the upper part, printed on transparency film, and mirrored. This way the whole upmost surface of the starwheel is a clean film, that can be written with an alcoholic pen in all positions, and wiped off with an alcoholic tissue without hurting the print.
The design is fixed, so the disks are not changeable, thus there is no reason to show the non-visible stars (this makes it more readable for the mid and high latitudes).
Because the vulnerability of the transparency film, I dropped the idea of the rotating cursor too, instead there is a declination scale on the stator (rotate the rotor above it as needed).
So, for every latitude range a separate starfinder must be printed, but it is so simple and cheap to build, that it should not be a problem.
The whole thing is program generated. I plan to make and share the whole series as soon as I could test it carefully, and might be, others can too.
If anyone would like to build and test it, I would appreciate any comments, suggestion and advices. I am especially lost with the asterism to be shown and the southern hemisphere.
Instructions: just print the base on a cardboard, only one of the starwheels on a transparency film, cut around the film and pin them together. (You must be VERY precise matching the rotor to the base!) I hacked a quick intro too, how to set up the Sun, planets and the Moon for one day. It is far not complete and does not cover the topic of how to use it, but who is familiar with things like this can figure it out soon.