I made this protractor to have a better understanding of which angle my Hwayeh MG90S micro servo points in with regard to the applied PWM signal from the microcontroller. The servo I have is quite similar to a standard 9G servo, but not excactly the same. The center cutout differs a bit from servo to servo. I have also made a simple arm for mounting on the servo with a center cutout of 4.90 mm.

The thickness of the protractor is 2.70 mm with 0.75 mm extrution cutouts for the numbers and marks. If you want to print this, add a color shift on 2.20 mm and you will get three layers of the second color on the top of the dial (when printing on 0.25 mm layer height). Or, simply use my pre-sliced file that has the color shift added :)