To install:Use 4 x 10mm M5 bolts and nuts to secure the printed part to the end plate.Remove the Grbl shield if its attached to the Arduino.Then secure the Arduino to the printed part using 3 x 10mm M3 bolts. I didn't use the fourth hole because the caps of my bolts were to big and would have interfered with the header pins on the Arduino.Reattach the Grbl shieldI used a zip tie through the long hole in the bottom of the printed part and the end plate to secure and relieve strain on the cablesI also zip tied the power cable to the bottom of the end plate to relieve stress there too.