“The concept of the SphereBot (or Egg-Bot) is really neat and innovative. For those of you who do not know, the SphereBot is a device that uses ordinary pens (sharpies, Rose Art markers, etc.) to draw on round objects. These can be anything, from ping pong balls, to golf balls, and even eggs. Vector Drawings are made in the free, open-source drawing program Inkscape, and are sent to an Arduino over serial using an easy-to-install extension as g-code. The Arduino receives these instructions and controls two stepper motors via the two A4988 stepper motor controllers. The object is rotated by one stepper motor while the pen is controlled by the other, the up-and-down motion of which is facilitated by a servo motor. Despite being relatively simple, the SphereBot is a really cool device, and is really fun to build.”