https://x.com/astro_Pettit/status/2083655015240016368/photo/1

Lions were once excited by custom equatorial mounts, when the skies were darker.  To this day, the good ones are quite expensive.  The trick is achieving both fine & coarse adjustments with the same mechanism, minimizing whiplash.  Then an astronaut showed a custom mount made from less expensive servocity parts.  Just get the gearing close enough & fine tune it with the motor speed.  

Noted it uses a ball mount for coarse adjustment.  The mount only has to move 1 speed in 1 direction, avoiding whiplash or clutches.  It has the advantage of not having to support any mass.

Still ponder if such a thing can be FDM modeled by making it large enough.  There just aren't any more stars at night & once you photograph everything, it's done.