sextant

This is a fully functional sextant. 

A sextant is an instrument generally used to measure the altitude of a celestial object above the horizon. Making this measurement is known as sighting the object, shooting the object, or taking a sight. The angle, and the time when it was measured, can be used to calculate a position line on a nautical or aeronautical chart. A common use of the sextant is to sight the sun at noon to find one’s latitude. Held horizontally, the sextant can be used to measure the angle between any two objects, such as between two lighthouses, which will, similarly, allow for calculation of a line of position on a chart.

Celestial navigation continues to be used by private yachtsmen, and particularly by long-distance cruising yachts around the world. For small cruising boat crews, celestial navigation is generally considered an essential skill when venturing beyond visual range of land. Although GPS (Global Positioning System) technology is reliable, offshore yachtsmen use celestial navigation as either a primary navigational tool or as a backup.

I must say, that this is a toy. I have used a 2d drawing from Internet, make some changes, remodel all the parts in 3d and make this toy. I have simplified some parts /no micrometer at the rotation handle, no spring at the handle, some parts are combined a.s.o./ By using a normal mirror, it can have some mistakes in the measurement \reflection\, but for showing the principle of work and measure is OK.

In my opinion is fully working and operational sextant, but printing in PLA and the mirrors could give not very accurate measurement, that's the reason to call it a toy. Plastic calipers are toys too :)

I can try it in the summer, when I go to the sea. 

The third plate is only for same telescope as this, that I have found!!!

P.P. I upload two step files. If someone has a problem with to tight rotation and zahnrad, print them.