Star tracker

I had some spare acrylic from another project, so I decided to get this project underway. The basic idea is very similar to Alex Kuzmuk's design.
https://kukuruku.co/post/diy-an-astro-tracker-in-two-nights/

I desired a simple and reliable star tracker, that was also small enough to carry, particularly for hiking or travelling.

The use of the Arduino provides a lot of flexibility in gear and thread choice. Mine uses an M6 thread to drive the barn door.

You may need to adapt it to your tripod/camera mount. There's a 6.5mm (1/4) hole for the camera mount. I used a 3d printed base for a ball joint from an old monopod, bolted in with a 6mm bolt. The tripod mount is designed to fit my Vanguard tripod with foot dimensions of 10mm high, top 32.3mm square, base 42mm square.

There's a couple of potential improvements that could be made. The hinge could be redesigned to incorporate bearings (see update 19/06/17). The gear system could benefit from bearings as well. In a 'perfect' sy