Spirographe

Draw spirograph curves: a pen fixed in a circle that rolls inside (hypotrochoid) or outside (epicycloid) a fixed ring.

R = fixed ring radius, r = rolling circle radius, d = pen distance from the rolling circle centre. Integer ratios R : r give closed patterns; Full closed curve uses one complete period.

Pick a preset or choose Custom and edit R, r, and d. Enable Show guides to see the ring and rolling circle.