GRBL 3 Axis Control Board
Output signal:
1: Fan: used for shaft motor cooling
2: Shaft: connect motor shaft, keep the same with power supply voltage, 5A electricity, if the motor power of the spindle is high, can connect external relays such as the switch.
G code M3 open, M5 closed, with version 0.9/1.1 of the firmware can adjust PWM, achieve the speed of the axis governing and tunable laser
3: X axis motor signal output, A4988 max 1.5A electric current
4: Y-axis motor signal output, A4988 max 1.5A electric current
5: Z-axis motor signal output, A4988 max 1.5A electric current

Input signal:
1: X-axis minimum limit X-
2: Y-axis minimum limit Y-
3: Z-axis minimum limit Z-
4: Reset button: press the button, system will restart, can be used for urgent stoping of machine

Package Contents：
1 x GRBL CNC Controller
1 x USB cable
3 x Heat sinks