CNC Shield V3.0 can be used as drive expansion board for engraving machine, 3D printer and other devices. There’re 4 slots in the board for stepper motor drive modules, can drive 4 stepper motors, and each step stepper motor only need two IO port, that is to say, 6 IO ports can quite well to manage three stepper motor, it’s very convenient to use. After insert Arduino CNC Shield V3.0 into Arduino UNO, and installed GRBL firmware then you can quickly DIY a CNC engraving machine.
The Arduino Nano is a small, complete, and breadboard-friendly board based on the ATmega328 (Arduino Nano 3.x). It has more or less the same functionality of the Arduino Duemilanove, but in a different package. It lacks only a DC power jack, and works with a Mini-B USB cable instead of a standard one.
The CNC Shield v4 is made for the control of 3D printers, milling and engraving machines. This version of the shield has 1 motor driver less than its predecessor, but is more compact and has room for an Arduino Nano. This board has 3 sockets for the installation of stepper motor drivers such as the A4988. Only 2 channels per motor are required to control this motor. There is also a connection for 2 end-stop switches per motor.