Centerfinder
thingiverse
I created a handy little tool to help discover some centers :) I built in an offset of 0.1mm for a 0.2mm sharpie thickness. Every parameter can be adjusted with the customizer's ease. Thanks also go out to Rudolf Huttary, whose amazing time-saving library I had to directly include because the customizer couldn't handle it on its own.
Download Model from thingiverse
With this file you will be able to print Centerfinder with your 3D printer. Click on the button and save the file on your computer to work, edit or customize your design. You can also find more 3D designs for printers on Centerfinder.