1. What is CNC shield expansion board?
A CNC Shield Expansion Board is an electronic device that allows you to build an engraving machine, 3D printer, mini CNC, and other similar devices using your Arduino nano. It is designed as a shield and can plug on top of an Arduino, requiring no external connections and wiring. The CNC Shield V4.0 has four slots on the board for plugging in a stepper motor drive module, which can drive one stepper motor each.