A simple box for all your GX lightgun needs

Coming Soon: a redesign using the Adafruit CH334F USB Hub Breakout is planned to replace the individual dual-USB boards currently used.

Updated files @ July 27th, 2024: Fixed dimensions of USB breakout board mounts on the base; adjusted top standoffs to account for breakouts spacing. Find the updated -V2 files attached!

Using a set of GX16 enabled lightguns? Want a clean setup? Can't be arsed to make your own square with holes? You want it? It's yours my friend! As long as you have enough connectors.

This is designed for the super special awesome OpenFIRE lightgun system, hence the top panel logo--but nothing's stopping anyone from using this with other DIY systems.

Disclaimer: I'm the lead maintainer of the OpenFIRE system, I just wanted something clean for my reference setup.

Compatible with most printers, requires no special setup or supports, just slice and print as displayed. Player sides are conveniently engraved on both the front and back panels. Both halves are friction fit, but screws help secure it.

This setup is made with GX16 connectors in mind - you could use either six or eight pins, just so long as it's consistent with the connectors used on your guns. Make sure the wiring is the same across all connectors and guns! You really don't want to know what 24V to ground is like...

For 8-pin connectors, this is the layout I recommend for the most featureful setup:

Bill Of Materials:

• GX16 Connectors (Male): At least 2pcs, + any guns you're retrofitting GX16 into.
• USB C Breakout Boards: 2pcs (Can also be found on Adafruit)
• 3.5mm Audio Panel Mount Connectors: At least 2pcs, + any pedals you're retrofitting audio jack outputs into. 3pins are the most you'll need.
• DC Barrel Plug Panel Mount Connectors: 2pcs, make sure the size matches your power supply! 5.5x2.1mm is the standard. Keep in mind that with these connectors specifically, Center is the shortest lead, and Shielding is the longest lead.
• Any DC Power Supply (5A or above): Make sure the barrel plug size matches your panel mounts! (preferably 5.5x2.1mm)
  • For most home solenoids (up to JF-1039 or equivalent), just one PSU (12V / 24V / Adjustable) with a DC power splitter (1Female to 2Male) will be enough.
  • For heavier duty arcade solenoids, you may want two separate PSUs - one per side.
• GX16 Prewired Connectors (Female-to-Female): At least 2pcs, can't hurt to have more on hand just in case.
• 3.5mm TRS Aux Cables: At least 2pcs, though in all likelihood you probably already have some of these. I recommend at least 2m length cables for adequate spacing for your pedals.
• 8mmx2mm Self-adhering Silicone Pads: At least 4 individual pads; optional, but can help add some friction to the box to keep the weight of the GX connectors from pulling as much.
• M3x12 screws: 2pcs; technically optional, but keeps both halves secured.
• M3x6 screws: 4pcs, for securing USB breakout boards to the base.
• 28AWG Wire: For all your USB/pedal wiring except for solenoid.
• 22AWG Wire: For your solenoid/DC VCC & GND wiring.

Quick Assembly Instructions:

Print both halves. Attach audio and power panel mounts and tighten nuts until they're snug - consider using hot glue to secure them and prevent the mounts from rotating in place. Attach USB breakouts to mounts in the back side with M3x6 screws.

Do not mount the GX connectors yet; instead, start tinning and soldering your wires of a decent length to the pins on the back side of the GX modules according to the desired pin layout. Remember that 22AWG wire is required for solenoid connectors to avoid EMI disconnects, and 28AWG for USB 5V/GND - you can use any smaller gauge wire for the rest. Wind the GX nuts in so the wires slip through, then fit the connectors through the holes (they are notched so they only go upright or upside-down).

Now, tighten the nuts to secure the GX connectors, with pins prewired. Now you can connect the wires to their respective pins.

• For the DC connectors specifically linked in the Bill of Materials above, remember that Center is the shortest lead, so (assuming your PSU is Center Positive) make sure that your Solenoid VCC wire connects to the shortest lead, and Solenoid GND connects to the longest lead.
• For the Audio connectors linked, connect to either Pin 1 or 2 (the two shortest leads on either 3pin or 4pin models); one goes to the Pedal line on the GX connector, the other can share GND with the USB breakout. If you're a psycho using a two-switch pedal, the longest Pin can go to Pedal 2 on the GX connector.
• For USB, connect the wires as you prefer, making sure the polarities match in your gun. GND can safely be shared with the Audio (Pedal) connector.

Once your wiring is done, make sure to plug in the USB and connect your GX wired gun. If that doesn't work, make sure your data lines match with the wiring in the gun's connections, and that D-/D+ wires are of roughly equal length. Once the gun's microcontroller is communicating fine with the PC, then test your pedal. Finally, verify your power connections, then power on the PSU and connect its plug to (either of) the power connectors, and test your solenoid.

If everything works, congratulations, your distro box is complete!

If not, um, I hope you didn't short 24V to ground on a Pico...

Now just attach the top panel to the base, ensuring the legs aren't snagging on any cables, and secure it with M3x12 screws. For that nice finishing touch, attach the silicone feet to the indentations on the underside of the base.

If you are running into data (dis)connection issues, you may want to ensure the cables connecting to the PC are of good quality with adequate shielding, are connected to native USB 2.0 ports if available, and that the power supply has ferrite for adequate noise filtering.