I’ve updated the GCode CNC Demo on Github with an example of how to run 4 stepper motors. It could be extended to 6, 8, or more.

Using the new Adafruit Motor Shield v2 and an Arduino UNO I’m showing how to control 4 stepper motors at once with GCode, the standard language for CNC machines like 3D printers, mills, and lathes. If you are designing your own machine this is the simplest way to get started. The code has four different examples that build on each other to grow your understanding. In theory this system could be expanded up to 32 stepper motors.