Tommy's Star Tracker (TS-2)

thingiverse

+++ This is a work in progress! I will posts updates as I have them. +++ UPDATES: APRIL 29 - Added a mount for a 5 x 24 finder scope to be used as a polar scope APRIL 29 - Added two sizes of counterweights MAY 2 - Small change to the counterweights (interior support no longer blocks bolt) MAY 7 - Added screws to finder scope mount MAY 7 - Added DEC axis for 90 degree mount MAY 11 - Tweaked the DEC mount and worm gear MAY 11 - Added extra small counterweight MAY 17 - Updated DEC top, drive gear, and worm gear (for strength) MAY 17 - Added BOM and PDF with build instructions MAY 20 - Added metric versions of some parts* JUNE 11 - Added a clutch mechanism JUNE 11 - Changed the vixen mount to be a clamp JUNE 11 - Trimmed up the 90 degree adapter and DEC top JUNE 24 - Updated Clutch Ring to screw on smoother This is my newest version of an equatorial star tracker for astrophotography. This can be hooked up to a simple arduino for basic tracking, but I'm planning to get it running on onStep with a RAMPS board. Note that you do not need to print the files labeled with "Metric" unless you are printing the metric-only version. This project is still in the testing phase, so please use these files at your own risk. Next on the lists of addons/improvments are: A computerized Goto version with motorized DEC axis A tripod with built in latitude base A dedicated arduino controller An OnStep controller A "Pro" version with a slightly higher build cost but a built in polar scope I'll keep this updated as the project moves along BOM (for main body only): - M3 20mm bolts x 4 - M3 15mm bolts x 10 - M3 5mm bolts x 3 - M3 nuts x 10 - 1/4" bolt 1" long x 1 - 1/4" bolt 3" long x 1 (drill a 4mm hole 17mm from the end for the worm gear screw) - 1/4" bolt 1 1/2" long x 2 (sharpen the ends of these to hold the pipe) - 1/4" bolt 1 1/4" long x 1 - 1/4" nut x 3 - 1/4" lock nut x 2 - 1/4" x 5/8" x 0.196" bearings x 3 (R4-2RS) - 3/4" x 1 3/8" x 1/2" bearings x 2 (standard lawn mower bearing such as AM118315) - 3/4" OD metal tube, 5 1/2" long x 1 (paint the inside flat black or you'll see reflections) - Keystone jack x 1 (I use RJ12 but an RJ45 would probably work too) - Nema 17 stepper x 1 (48mm length; I use 17HS19-2004S1) - 20t GT2 pulley (or you can print one) - 200mm GT2 belt (I guess you could print that too) For a tripod with polar alignment, see https://www.thingiverse.com/thing:4868538 The latitude base in the pictures can be found here: https://www.thingiverse.com/thing:4776560 For a Vixen Dovetail bar, see https://www.thingiverse.com/thing:4888474 * for metric versions of parts, the 1/4" bolts are now M6 hex bolts, the tubes are both 20mm OD, the large bearings are 20x32x7, and the small bearings are 6x19x6. If you don't see a part file with the word Metric after it, it's because the regular version doesn't use any imperial parts <code> // TOMMY'S STAR TRACKER <code> const int stepPin = 9; // Set the stepping pin to pin 9 const int dirPin = 8; // Set the direct pin to pin 8 <code> (HASHTAG SYMBOL HERE)define DELAY 67.343 // This is the delay in between steps in milliseconds <code> void setup() { pinMode (stepPin, OUTPUT); // Set stepPin as output pinMode (dirPin, OUTPUT); // Set dirPin as output digitalWrite (dirPin, HIGH); // Set the direction to clockwise } <code> void loop() { digitalWrite (stepPin, HIGH); // Start a stepper pulse delay (DELAY); // Wait digitalWrite (stepPin, LOW); // End a stepper pulse delay (DELAY); // Wait and repeat } </code>