This is a button box designed to use full-size arcade buttons and to mount the most common joystick control board available on sites like eBay and Amazon.
1-1/8" Suzo Happ buttons (the ones with the long screw and nut to fasten them) are recommended, though you can use any full-size (1-1/8") arcade button that fixes in place with a nut. Sanwa and similar buttons aren't recommended, but may work. These buttons are available from common online retailers and can be had for as cheap as $1 per button, or $2 or so per button if you buy them with the microswitch included.
There are four posts inside the box to press-fit the joystick board to, though after building a few of these the consistency on the mounting holes on the joystick boards isn't great, so you may need to either flex the posts to get them into the mounting holes on the board, or less ideally snap the posts off and just use hot glue. You can also simply leave the joystick board floating inside of the box safely.
The cable strain relief is a simple press-fit part. Feed the USB cable into the box, then press the strain relief part onto the cable with the opening facing downwards. Then press it into the hole on the box from the inside. On a reasonably tuned printer it will be a snug but doable press-fit. The part is very small, so if it's too tight you can re-print it at 2% less scale until it fits snugly. It's recommended to tie a small knot in the cable on the inside of the box to prevent the cable pulling on the joystick board connector.
Wiring the buttons requires no soldering, as the most common joystick board comes with plug in wires that simply plug into the board and then slide onto the microswitches. Once finished, the button box shows up as a normal joystick on any Windows, Mac, or Linux computer. It does not work on consoles, only computers.
The joystick board that works best is the one commonly called "zero delay joystick board" or "zero delay encoder". They are sold under many brands and are typically about $10-12 dollars and come with the board, wire bundles to wire up your buttons, and a USB cable to connect other your PC.
You'll need eight 1-1/8" arcade buttons. Again, I recommend Suzo Happ buttons that fix in place with a nut. You'll also need eight microswitches, which may be included with your buttons depending on where you buy them. These are easily available at most online retailers.
Requires 4 #6-32 (or M3.5x .6 in metric) screws to fasten the top to the body. A screw test jig is included so that you print it and bring it to the hardware store or use it to test screws that you have handy. Screws can be of any length, though 1/2 inch is plenty. No brass inserts are needed! Simply screw into the holes in the print. They have knobs inside so that the screw will go in easily. Only turn the screw until you feel a bit of resistance, then stop. Over-tightening will strip out the screw holes. The screws are counter-sunk so that the button surface is flush.
