This is based on the “Corner Protractor” model by nightfox90, but heavily modified. I added a larger, finer, multi-color scale and snap-fit connectors so that it does not fall apart. Also, you can now measure more extreme obtuse and acute angles (15° - 165°) without the measurement being obscured by the arms.

Make sure that you print the Snap-fit-test.stl first and tune the “XY size/hole/contour compensation”  settings (or flow rate) until it fits perfectly. The connectors should take some force to put together (place them on top of each other and hit them with your hand) and they should offer some resistance to rotation, so that the protractor does not move while you try to read the measurement.

The file Protractor_Multicolor_generic.3mf contains the three multi-color scales already set up. Since the lines on the multi-color scale are very thin, you will need to use the Arachne wall generator and set the “Minimum wall width” to something like 30% (the scale on the photo was printed on a Bambulab X1C with these settings). This is already set up for the three scales if you open the file in OrcaSlicer. Just disable the two scales you don't want.

You will need to print:

• 1x Base_Arm.stl

• 1x Cross_Arm_Clip.stl

• 1x Guage_Arm_LargerScale_Clip.stl

• 1x Main_Arm_Clip.stl

• 1x ProtractorLarger_Clip.stl if you don't want a multi-color print

• OR 1x ProtractorLarger_NoScale_Clip.stl combined with one of the ProtractorLarger_Scale files in a different color.

Assemble as seen on the photos.