This is a replica of a compass as you can find in every aircraft. It is designed to be used with a NEMA 17 stepper motor (like this one : https://amzn.eu/d/48ZMKHg) and with a digital sensor (like these : https://amzn.eu/d/fukfElb). The PDF is the background to be printed and glued to the turning disc.

I will use it connected to a stepper driver shield for an Arduino Uno. I plan on using it for DCS World through the use of DCS Bios.

To assemble the different parts you will need 5 M3 screws for the stepper motor (M3x5mm) and the digital sensor, 4 M3 screws (M3x10 mm) to attach the front plane to the spacers, 4 spacers (20 mm, M3) and four nuts (M3) to attch the spacers to the motor support.

Update : I have adjusted the backplate where the stepper is attached so the sensor can now be secured in position by a 10 mm M3 screw and a nut.

UPDATE V2:
Changed the design to ease the zeroing : in the original design the window is too small and sometimes the sensor doesn't see through it, which leads to an ill positioned zero.
To correct that defect I have significantly changed the design. All parts are labelled V2.
The windows being no longer necessary I have also edited the graphic part.

If you want to build the V2 (please do so, it is way better than V1) of this compass, only print the parts that are labelled V2 AND the front plane that has not been modified. The remix with embossed markings has also been updated.