I followed the original project on this upgrade.
Here is a video of the overview.
I built this enclosure out of .25" melamine with .5" square dowels in the corners.
The 3 stepper motors are wired into 4-pin mic/CB connectors. The spindle and Arduino power are wired into simple center pin power connectors.
The 110v coming in was taken out of an old PC Power Supply to wire into the Enclosed DC Power Supply.
The top of the box is a .125" thick clear acrylic that is really just sitting on top for now. I drilled holes into it so I could mount the Speed Controllers potentiometer and also the E-Stop button.
All of the wire inside of the box was hacked from that same PC Power Supply.
The fan on top of the GRBL Shield is a 5v fan that helps keep the Motor Controller cool while cutting and is wired right into the Arduino 5v.
The USB for now is just passed through the enclosure to the Arduino but I have plans to mount a USB Passthrough Connector.
In order to access the “Reset” button on the GRBL Shield/Arduino, I hooked up an old monetary reset button from an old PC case (its the blue/white wire you can see sticking out of the right side of the enclosure in the picture. I will eventually mount this into the top acrylic as well.