Vixen Optics put this Right Ascension Motor with Star Book One set together for their Advance Polaris Mount. It consists of a Right Ascension (RA) motor for tracking heavenly bodies as they move across the night sky and a hand controller to manually find celestial objects and automatically track them.
The low-vibration 360° micro-pulse motor is specifically built to fit seamlessly onto the AP mount and gets its power from the mount centralized power system. It features a 140-tooth worm wheel with a brass shaft and an aluminum alloy rotation axis. Vixen's Star Book One (SB1) is a basic controller and gives you control of the motor. It automatically detects the mount it is plugged into and adjusts its capabilities accordingly. This means that if you install the optional Declination motor, the SB1 will detect it and give you control of it. The controller has both backlash compensation to minimize or eliminate the play between the teeth in the worm wheel for smoother tracking, and Periodic Error Correction (PEC) so you can program out inherent errors in tracking so objects will remain centered in your field of view during long observation sessions or long-exposure astrophotography. To track near and deep space objects, the SB1 has four speeds: sidereal, Kings Rate, lunar, and solar. To make the AP mount more versatile, the SB1 can work in either the Northern or Southern hemispheres.