Celestaire Artificial Horizon Adapter for Davis Sextants
by biketool, published
Press fit adapter for Celestaire David White artificial horizon to fit Davis Mk12, Mk15, and Mk25 plastic sextants .
Print at 10% size be sure to use a slic3r ratio of 1.0 for infill and adjust your filament ratio so your walls will be fused properly.
Press fit the more narrow end(22mm) into artificial horizon, you need not cut off the Plath/Tamiya fork mounts for standard sextants unless you want, larger(23mm) tube end fits into the friction fit telescope mount on Davis plastic sextants. This may appear wrong size but the inside of the Celestaire sight sun shade tapers inward to a cylindrical area, tests show a perfect hand tight fit in the sight and proper removable friction fit in the sextant.
Requires no boresighting as the bubble will always gravity align with the horizon line in the artificial horizon.
Don't be concerned that the horizon side of the mirror is blocked by the bubble, you now align the the center of the bubble with the horizon line then adjust the sextant to allign a celestial object to the black line as you would with the sea horizon, it is a bit more work to allign three objects than the regular sun and horizon. Continue to use sun filters for both mirrors as required.
The Celestaire bubble horizon will still work on full size sextants with fork mount sights while this adapter is installed.
An artificial horizon sight is required for celestial navigation anytime a good sea horizon is not viewable due to weather, terrain, or an inland location; it is also required when you are at an unknown height above sea level including airborne. This initially incompatible sextant and artificial horizon combination when joined together with this adapter forms the most affordable realistic inland, airborne, and bad weather celestial navigation tool currently available.
The alternative is several thousand dollars for a high end commercial navigators sextant and bubble sight that in daytime is not functionally better for the average navigator or using a bowl of water or folding water box for reflecting the sun which Davis actually sells for inland practice.
The Celestaire sight uses a horizontal slit to force proper eye alignment, this makes it less useful than a two axis bubble sight for shooting smaller stars after dark.