large lasercut compasses for drawing circles

thingiverse

I needed to create large circles, allowing me to carefully sketch a portion of my design on a whiteboard. Unable to locate any big compasses, I built one myself! The intended purpose of this design is for lasercutting. It comes in three sizes: 20cm, 30cm, and 50cm lengths. To build it, cut two matching pieces and attach them together with a 1/4" machine screw (or similar size), using washers to keep the arms from sticking together. There are slots meant for rubber banding the working ends of the compass – markers, pens, pencils, etc. I used a pencil eraser as the center point since I was drawing on a whiteboard (it worked okay, not great), but if you're drawing on paper you could use a sharp pencil, nail, etc., as your center.