• Install the GRBL into your Arduino. Find here some useful instructions on how to do this.
• Download and install “Universal Gcode Sender” for sending Gcode commands to the Arduino. You can download this program here.
• Open Universal Gcode Sender and connect to the Arduino.
  •  Make sure that the belts are not connected.
  •  Test each motor’s rotation direction by sending the G0 X0 or G0 Y0 command. Change the wiring if needed to make the motors work as intended.
  •  Load a Gcode file. Make sure that the Gcode won’t make your CNC collide with your borders.
  • Run the Gcode file.

The assembly process is quite straightforward:

1. Assembly the pulleys and pulley holders (3 in total).
2. Assembly the pulleys, the motors and the motor holders (3 in total).
3. Assembly the X shafts and the X shaft holders (2 in total).
4. Assembly the movable left side base.

  5. Assembly the movable right side base.

  6. Assembly the movable middle base.

  7. Assembly all the bases and shafts accordingly.

  8. Place the belts and make sure to tighten them up.

  9. Manually move the X and Y bases to check for uneven movements or noises. Try loosing/tightening the screws and adjusting the different elements to make the movements as smooth as possible.

Before proceeding with the electronics, I really recommend checking that all the components work properly. Pay special attention to A4988 modules, as they need to be tuned before being used. Find a nice tutorial about tuning them here.

After ensuring that all the components work properly follow next diagram to setup your electronics. Don't forget to connect the X.STEPS/DIR pins so the commands in the A axis are the same as the ones in the X axis (remember that the X direction is controlled by two motors!).