Telescope altitude drive

thingiverse

This project involves motorizing a 300mm Dobsonian telescope's Azimuth/Altitude mount using a belt and stepper motor. The large quarter circle pulley, bolted to the scope, and a small pulley on the stepper motor work together for zero-backlash, high-speed driving with an accuracy of 11 arcseconds per microstep. Further gearing down can provide better resolution but may pose challenges in achieving zero backlash. A video animation is available at http://youtu.be/Y1-zTE1iXZs. Current tasks include printing, testing, and performing resolution/accuracy tests. Longer term goals involve creating manual control for constant rate, an Arduino sketch to convert hour angle/declination to Az/Alt, and a Stellarium plugin for slew commands using gcode if possible. The design has been returned from review, and the plate needs to be printed, skate bearings installed in idlers, and the mount bolted together with the stepper motor attached.