Really big drawing of epitrochoids and hypotrochoids

This is my newest ball-point pen drawing. It’s nearly 40 inches in diameter  and features epitrochoids and hypotrochoids if you are into the math terms.

One of the detail shots shows the edge of one of my parametric drawing gears used make this drawing. A pen is in the full drawing shot to show scale. I taped two pieces of paper together for this drawing as I didn’t have any paper that was 40 x 40.