Note: The files don't have the "Moshi's Arcade" text at the top of the machine. It's your machine if you print it, after all :)
BOM (Bill of Materials)
Most of the parts are simple - print them with your usual amount of top/bottom layers, perimeters, and some sparse infill (Anywhere between 5% and 10%).
The back can be printed as-is. However, I liked the hexagonal aesthetic (shown in my pictures). To print it like that, use a 25% hexagonal infill, with 0 bottom layers and 0 top layers. Note that the captive nut holders do need top layers, so set your slicer to return doing top layers after 3mm height. This ratio also lets you use M3 nuts and bolts to mount things to the back, like a raspberry pi case, or a speaker.
Start by mounting the LCD. Slip nuts into their captive slots on the LCD holder, then use short M3 bolts to mount the LCD into the holder. Connect micro USB and HDMI to the screen now.
Connect the two halves of each of the frame sides to one another using the longer M3 bolts (M3x18 or higher).
Mount each side to the LCD holder using the two captive nuts (on each side). You might need to bend the HDMI cable a little to make it fit.
Mount the controller pad to the sides and make sure it sits flush against the LCD holder.
Mount the front control panel and bannertop to make the assembly sturdier.
At this point you should start connecting the joystick and buttons. Joystick needs M4 nuts and bolts to mount, and the buttons are simply pushed into their slots. This is also a good point to start wiring the buttons and joystick to the Zero Delay USB encoder.
Once the buttons and joystick are wired, you can test the electronic side of things by connecting the Raspberry Pi to the LCD and to the Zero Delay USB encoder. Consult the RetroPie documentation on how to install RetroPie on your Raspberry Pi.
When you're certain everything works correctly, mount the Zero Delay USB encoder to the back of the LCD holder using some double sided tape.
If you printed the back as a solid, mount the Raspberry Pi to it using some double sided tape. If you printed it without top/bottom layers using hexagonal infill, you can use M3 nuts and bolts to mount a printed case like this one.
Mount the back plate to the rest of the case and have fun!