Thước đo góc (Protractor) xoay được

I made a Protractor, It can draw circles 、angles and measuring angle.(It is rotatable)

Special Tips:
When it's finished printing,it  might be a little tight.
let it takes a few more turns.

This model was printed using PLA. (fill in 10~15%，using a lower layer hight (0.15~0.2mm)，no support)