Arduino cnc shield v3

New Stock Arduino cnc shield v3 engraving machine 3D printer A4988 expansion board. Expansion board can use as engraving machines, 3D printers and kindly. Total 4 slots channel stepper motor driver module ** When inserting A4988 module, must be careful not to insert opposite. Stepper motor wiring as follows: 2A, 2B is a group (red, green), 1A, 1B is a group (blue, yellow), if want to change direction, can be change the position of one group , for example 2A, 2B mutually exchanged