Tommy's Motorized Equatorial Mount (TS-1)

thingiverse

NOTE: This project has been replaced by "Tommy's Star Tracker" https://www.thingiverse.com/thing:4839602 A 3D printed star tracker mount for visual astronomy and astrophotography! This design is based on SimonRob's Equatorial Mount for DSLRs (https://www.thingiverse.com/thing:4365068), but it's been upgraded to handle smooth tracking on a lightweight telescope setup. A huge thanks to him for laying the groundwork, and I highly recommend checking his thing out for a great set of build instructions. Note that I also used Trigubovich's Compact planetary gearbox (https://www.thingiverse.com/thing:2114390) , but couldn't get the remix connection to work; I'll see if I can fix that. Also, don't forget the matching latitude base or tripod and the 3D printed counterweight! https://www.thingiverse.com/thing:4868538 https://www.thingiverse.com/thing:4776560 https://www.thingiverse.com/thing:4755514 Parts List: - a ball head mount - a Nema 17 motor - electronics to drive the motor (I used an arduino) - a 200mm GT2 belt - a 20T GT2 pulley - Two R8-2RS bearings (1/2" x 1 1/8" x 5/16") - One 623ZZ bearing (3mm x 10mm x 4mm) - Four M3 40mm screws for the Nema motor - an M5 bolt for the planetary gear output - a bunch of short M3 bolts and nuts for assembley - a 1/2" OD tube (I had aluminum on hand, but it's a common size for rigid copper) - a 3/8" threaded rod and nuts for the counterweight (or metric equivalent should be fine) The reduction ratio is 1:17 (1:4 at the planetary gear and 1:4.25 at the pulley) - Telescope should rotate every 23.9344 hours - after the 1:17 reduction that's 1.4079 hours - that would equal 5068.47 seconds - Nema has 200 steps or 6400 microsteps (at 32 microsteps) - 5068.47 sec / 6400 microsteps - 0.7919485 seconds per microstep If microstepping at 32, you should have one step every 0.7919485 seconds. // TOMMY'S EQUATORIAL MOUNT const int stepPin = 9; // Set the stepping pin to pin 9 const int dirPin = 8; // Set the direct pin to pin 8 #define DELAY 791.95 // This is the delay in between steps in milliseconds void setup() { pinMode (stepPin, OUTPUT); // Set stepPin as output pinMode (dirPin, OUTPUT); // Set dirPin as output digitalWrite (dirPin, HIGH); // Set the direction to clockwise } void loop() { digitalWrite (stepPin, HIGH); // Start a stepper pulse delay (DELAY); // Wait digitalWrite (stepPin, LOW); // End a stepper pulse delay (DELAY); // Wait and repeat }