Cardiod with gear

A cardioid is a plane curve traced by a point on the perimeter of a circle that is rolling around a fixed circle of the same radius.

I decided to use gears instead of plain round discs to draw a cardioid These two gears have the same teeth and hence same radius. These holes are used to hold a sketch pen used to trace the path as we move one gear around another one.

Print 2 copies of the same Gear.

Here is the explainer video of the same.