Star follower

Many photographers would like to take a picture of night sky object e.g. Andromeda galaxy or some colorful Nebulas. To achieve this goal we need to take long exposure photo. To eliminate movement of the sky the camera must be turning the same speed. Assuming the Polaris (North Star) is not moving we can aim it through the hole in the main shaft. The stepper motor is set to microstepping of 20,000 steps/rev (Now I would recommend to use a additional gearbox or print higher HTD gears ratio to lower steps/rev). The 3D printed parts are essential to carry the gear bearing with the shaft to perform smooth revolutions. Optional parts are joints to improve device rigidity. (In PrusaSlicer need to be added stops for M6 nuts).

Other parts, like weight to make work for stepper motor easier was chosen steel screw rod with some metal rings. Pieces of wooden log  are also used to spare some filament ;) 

Photo of Andromeda galaxy is taken from this mount (exposure time is 11 minutes) 

To protect electronics is used shoes box,