This is one of the simplest CNC builds we’ve seen but it still functions quite well. It’s a clone of the EggBot, but is aimed at printing on spherical Ping Pong balls rather than oblong eggs. [Chad] calls it the Spherebot, but you should be careful not to confuse it with the morphing sphere robot which can walk around like a hexapod.
The project is both mechanically and electronically simple. The body of the printer is made up of three acrylic plates, which we’re sure were clamped together when drilling holes to guarantee proper alignment. Threaded rod and nuts are used to mount the plates to one another, as well as to hold the sphere in place while printing. One stepper motor turns the ball while the other pivots the pen mount. A servo motor is responsible for lifting the pen. The entire thing is driven by an Arduino along with two stepper motor driver boards. Don’t miss [Chad's] presentation embedded after the break.