This is all the parts to make a functioning star compass like the one in the show Made in Abyss. If it is printed correctly you should be able to make it balance and actually point downwards all on its own.
Since I can't print a clear ball I used these 70mm clear Christmas ornament balls you can purchase from amazon. The outer ring is also held in place by the tabs on the ointments and will hide the seam on the plastic ball at the same time. (I'm pretty proud of that part) (https://www.amazon.com/gp/product/B01GFW8HPQ/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1)
For the pivot's I used the smallest sowing needles that I could buy from my local craft store. I also bought a .5mm drill bit from the hardware store and used that to drill a roughly 2mm deep hole into the compass for the needle points to sit inside of. If the hinge is done correctly it makes for a really low friction pivot that allows the compass to spin freely while still being very secure, I can actually shake the ball decently hard without the compass popping off the hinges.
The next part is also very important. The best way I found to get the needles to securely mount inside the 3D printed inner ring and also in to the clear ornament, are to actually drill a really small pilot hole then heat the needle with a candle or something so you can push it though and melt the plastic to the exact diameter of the needle then just add a little CA glue to make sure it doesn't go anywhere.
As far as balancing the center go's its gonna depend on the version you make. I know that on the 2.0 version I was able to drill out weight from the inside outwards under the socket that the bottom snaps into, that way the hole would be hidden from sight.
I know it is not easy to make but I promise it can be done with a little patience and ingenuity. Good Luck!
It can defiantly be printed with an FDM printer. My friend was able to make a pretty good looking center at 200% size on his Ender 3 Pro. So if you put in the work to sand it and finish it it can turn out pretty good.