Recently I had to cut an methacrylate circle of a certain diameter and I had no compass or similar tool to draw the circle. Looked here for a design that meet my needs but couldn't find any. I like simple and functional things and I remembered some tool my drawing teacher used when I was a child... that came to my mind. Not a joke!! This works for me better than any toy. My hands handle this well, not like some toys that always break in my hands. I needed something that I could attach several kind of tools, to draw, to mark, to pinch, etc. Don't make mistake, there are awesome compass designs out there, but as always I wanted my own design to be able to change it. I believe in the open source hardware so there are the FreeCAD sources. So I had to begin a little project to design this manual drafting compass. I call it the poor man's compass because it is simple to print, simple to mount, and simple to use, but also sturdy and durable. Printing requires no support. Use an M4 hex bolt, a washer or two, and a M4 wingnut to join the two parts. Use some rubber bands to fix your favourite tools to the wings of the compass, done. Once more an simple design for a simple thing.

UPDATE (16-JUN-2016): Increased M4 nut & bolt tolerances for an easier insert without filing or pressing or heating.