Introduction: Z Probe for 3018 Pro


I wanted to mill PCBs on mei 3018 Pro but it had no Z Probe Pin.
Because I couldn't find any Instructions how to do it, i made in myself.


  • Solder Iron
  • Wire Stripper
  • Wire Cutter
  • Thin wire (or better an enamelled copper wire)

Step 1: Z Probe Pin

The CNC runs on GRBL 1.1 so I found the right Pin where the Z Probe should be connectet to.
My CNC Controller Board had an ATMega328 so the Z Probe should be connected on Pin 28 (SDA)

Step 2: Pull Up

To prevent the Z-Probe from triggering in an undefined way, a pull up resistor is needed.

I used an 4,7kOhm Resistor. The Resistor is Solderd between Pin 28 and VCC of the ATMega. (see Picture)

Step 3: Connect

The Z Probe can be connected between Pin28 and GND. There is no need to change the Firmware.

Only on GRBLControl I needed to add a command for the Z-Probe: "G38.2 Z-1 F1; G92 Z0"

The last fracture of the command sets the Z Axis of the Machine on zero. There you can change the thickness of your Probe.