Very large epitrochoid drawing in progress blue and black ballpoint pen

Line drawing in progress is about 4-1/2 feet in diameter. The exterior epitrochoid line patterns are complete, I think. I rotated the outer drawing gear around the inner gear 2,016 times, if I did my math correctly.

Ink lines alternate black and blue, from a distance the color blends together creating a beautiful indigo coloring.

I do these large drawings on the floor as I don’t have a table large enough to hold them. Next I’ll add interior hypotrochoid patterns. Will post the finished results.

Parametric drawing in progress of large epitrochoid
Epitrochoid patterns are about 4-1/2 feet in diameter. Eight expended pens/refills.
Ballpoint pen drawing of detail of cusps of epitrochoid.
Ballpoint pen drawing detail showing main cusp of epitrochoid. Blue and black alternating lines.