Simple compass

thingiverse

Recently I had to draw a circle bigger than my compass, so I decided to build one myself. To get started, you'll need a 3/16 inch threaded rod and four nuts, two #6 by 3/4 inch screws with nuts, and a needle tip (cut off a piece of a thick sewing needle). In the writing end, you can use a pencil, a ballpoint pen, a marker, or almost any other writing instrument. You might need to attach the pencil holder screws using epoxy, as the nut holes are smaller than the nuts. They'll stay in place by pressure alone. To put the needle in its spot, simply heat it up a bit – PLA softens at very low temperatures.