So after a couple of days of printing, and a little sanding, some assembly, and not a tiny bit of cursing, I have a printed orrery gear assembly for our Earth-Moon Orrery.
It’s a little stiff, but that’s to be expected since I haven’t perfected the gears through sanding. (That means carefully going through each tooth with a tiny little strip of sandpaper and polishing down all the little rough edges.) Of course the mechanism also needs to set for a few days; I’ve found 3D prints out of the FormLabs Form 2 printer generally take a couple of days to set before the parts seem totally cured. (Of course I could buy the system FormLabs sells to harden parts–but I haven’t.)
The ideal way to build this mechanism, of course, is out of brass–and the next thing for me to do is figure out how to cut brass gears and replicate this mechanism in aluminum and brass.
But as of now, our very simple little mechanism works.