We will need a piece of carton paper or card stock (I cut mine from a cereal carton box), a ruler, a sewing pin, a toothpick and 2 pens/pencils.
Make a rectangle out of your carton paper. Mark points with an interval of 10mm in between and poke through the dots with a sewing pin. Enlarge the holes with a toothpick.
And that's it, we are done! Let’s try it out.
Take out 2 pens and decide how big you want your circle to be. The distance between the 2 pens is half the diameter of the circle. Image: The distance between the 2 pens is 30mm so we will have a 60mm wide circle.
One pen will serve as the pivot (this one does not move) and the other one will be the drawer. Have a try!