Nice. First 3D-printed replica wins my vote as a teaching aid and generally cool retro hack. We need more of this offline tech stuff.
Combine a compass and other navigational tools, and I see an interesting evolution as a sort of retro, creative-commons, git-forkable hacker-army object.
Elegant device that enables you to get an accurate Sun altitude at specific times of day, and hence a position fix. No moving parts.
I think the 'hack' here is to think through the navigation requirements of someone sailing across an ocean. Do they need to be able to find a position at an arbitrary time (the proper sextant) or would the ability to find a position at some time during daylight be enough? The result is a device that is robust and that can be kept in a 35mm film cassette.
When you figure out how to 3d print a birefringent material, let me know. In fact, when you get a hobby-grade 3d printer to print something you can actually see through, let me know.
Sure. Obviously not everything comes from a machine. One can probably rely on people finding some crystal separately and/or if feasible order bulk-printed 3D transparent material (no idea of light properties of those, though I know they exist... just saw some this morning!).
My understanding from the image is that the operation is based upon the combination of two directional light beams through holes driven by an opaque piece with a rotating disc. Whether this was used at the time or not, it still seems a clear way to demonstrate the concepts.
At the very least the operation could perhaps be usefully modelled three dimensionally using raytracing, perhaps also with the capacity to vary basic optical properties of the transparent crystal feature such as reflectiveness, refractiveness and average opacity, as well as atmospheric conditions encountered in the seas ancient European seafaring peoples are known to have sailed.
Combine a compass and other navigational tools, and I see an interesting evolution as a sort of retro, creative-commons, git-forkable hacker-army object.