In 2023, I had the opportunity to exhibit at Open Sauce, an exciting new event organized by YouTuber William Osman, held at Pier 35 in San Francisco. Open Sauce is a giant science and maker fair where the focus is on "fun" science rather than traditional "serious" science. To illustrate the creativity on display, my booth neighbors at the 2023 event included a quadruped robotic dog, a camera robot that printed photos on receipt paper, and a giant Furby costume.

At the event, I showcased my latest creation: an 18"x17"x28" tabletop arcade machine running my game, Thetawave. This was the third cabinet I had designed and built, featuring a second display for an animated Thetawave logo. Although I spent most of the event at my booth, I thoroughly enjoyed demonstrating the arcade machine to attendees, receiving feedback on the game, and networking with fellow makers and tech enthusiasts.

The Metalmancy booth at Open Sauce 2023 featuring a tabletop arcade machine running Thetawave.

When exhibitor applications for 2024 opened, I knew I had to participate again, this time with an improved and even more impressive machine.

Issues with the 2023 Arcade Machine

The 2023 arcade machine was the best I had built so far, but it still had room for improvement. Traveling from Minneapolis to San Francisco by plane, I encountered a significant issue: upon arrival, I found the screen protector completely shattered. The monitor panel had slightly caved in, likely due to rough handling during transit. This reminded me of my experience at CES 2020, where I saw the Delta exo-suit and imagined my poor arcade machine being suplexed into the luggage bay by a mech-assisted baggage handler. Upon further investigation, I realized the problem stemmed from the monitor panel lacking sufficient support. It needed at least one additional point of reinforcement to remain structurally sound under the weight of the heavy monitor.

A distinguishing feature of my arcade machines is that they are constructed from steel rather than wood. I chose steel due to my background and experience in metalworking and welding, making it the material I am most comfortable working with. My process for building these machines starts with ordering custom laser-cut steel parts from a local metal shop. Once I receive the parts, I fit them together and tack weld them in place. After ensuring the fit is perfect, I proceed with longer, stronger welds to securely hold the enclosure together. To finish, I round the corners with a grinder, smooth the surfaces with a wire brush, and paint the machine with black automotive paint for a sleek and durable finish. After painting, I take the enclosure to a vinyl shop where they apply custom graphic wraps to the exterior, typically featuring art from the game intended to be played on the machine.

There are a couple of issues with the build process. First, the requirement for welding to assemble the machines is inaccessible to most makers. While this method works if the machines are primarily assembled by myself or other skilled welders in professional weld shops, it presents a significant barrier if I want to distribute the machines as kits for makers to assemble themselves. Welding requires specialized skills and equipment, which many hobbyists and makers do not have, making it difficult for them to complete the assembly on their own.

Welding together the enclosure of an arcade machine.

The second issue is the quality of the graphic wrap on the exterior of the machine. On corners, it tends to ripple, fray, and peel, which looks unattractive. Transporting the cabinets around exacerbates this problem. There are a few potential solutions to this issue. One option is to glue bumpers on the corners to hide the imperfections and protect them from damage. Another is to wrap the vinyl around the corners to provide more surface area for adhesion. However, the solution I ultimately chose was to ditch the vinyl decal wrap altogether, which I'll elaborate on later.

A bubble of air under the vinyl wrap on the top of the arcade machine.

A crucial feature of any arcade machine is its ability to run games effectively. The arcade machines I build are designed to run games developed with contemporary tools, which may include graphics-intensive features such as 3D graphics, shaders, and bloom effects. For the 2023 machine, I decided to use a LattePanda Delta 3, a single-board computer equipped with an Intel Celeron N5105 processor and Intel UHD Graphics. I chose this board because it offered adequate performance to run my game, but also because in included an Arduino co-processor. This co-processor made it very easy to control the LEDs in the buttons and along the edge of the screen.

The electronics in the back of the arcade machine, including the Latte Panda Delta 3 single board computer.

When I brought this machine to events, starting with Open Sauce, I received a lot of feedback from players indicating that the controls felt unresponsive. Initially, I attributed this to the physics-enabled movement in the game. Many players of Thetawave are surprised by the incorporation of acceleration and velocity in the player's movement, and I assumed their feedback was a reflection of this observation. However, upon further investigation, I discovered the actual issue. In slower environments, such as on the LattePanda and when running the web build in a browser, the game slows down the physics simulation instead of skipping frames. This created a "slow motion" effect, leading to input lag and occasionally causing strange spawning behaviors due to timers in the game progressing faster than the physics simulation. It became clear that the computer would need to be upgraded for future machines.

Building a Better Arcade Machine

Before starting on the new arcade design, I had already decided to scale down the size of the machine. While I enjoy building large arcade machines, smaller machines offer many advantages for both me and potential customers. They are easier to transport, less expensive to produce, and more structurally stable. Additionally, I chose to eliminate welding as a requirement for assembling the new design. Instead, I opted to add flanges with mounting holes to sheet metal parts in the center that would screw onto the side panels. I strategically placed these flanges in areas where I would have otherwise used a weld. To address the previous issue with the monitor panel, I added a flange halfway up the panel to provide extra support and prevent another mishap during travel.

A Fusion screenshot of the back of the new arcade design. Notice the flange with the locknut in the bottom left of the image.

For the majority of the design process I figured I would just try vinyl wrapping the mini arcade machines again, but after I ordered the parts and assembled the first machine, I got an idea that I couldn't believe I hadn't thought of earlier. Since my arcade machines are made of metal I had a whole new medium of graphics that I could use: magnets! After realizing this, I quickly made a pattern for the all of the visible surfaces of the cabinet and sent them off along with the art to create die cut magnets. When I received the magnets, they worked just as expected. The graphics were vibrant, the edges were thin, and they adhered to the sides of the machine enough to to stay in place, but could also be easily removed and replaced when needed.

As mentioned previously, the LattePanda Delta 3 single-board computer was too under-powered to run Thetawave at a decent frame-rate, so a new computer needed to be chosen. Unfortunately, by this point, it was too close to the date of Open Sauce 2024 to test out a variety single-board computers. I needed one that could run games like Thetawave that use 3D graphics, and some costly visually effects like bloom. I ended up settling on using a Steam Deck handheld gaming PC. While the Steam Deck is very much over kill for running a game like Thetawave, it is still relatively small and could be positioned behind the arcade machine and plug into a dock on the inside of the machine to charge and connect to the controller inputs and the display.

The Steamdeck behind the arcade machine.

It was now getting very close to the date of Open Sauce 2024 and now that I had figured out all of the details and improvements from the previous design, it was time to order all of the parts and assemble. Below is a table of where I ordered all of the parts from along with some comments on why I used them.

I decided on ordering the parts required to build two of this arcade machine design. I figured that I could run Thetawave on one of them, and either find a second game to showcase on the second one, or link the arcade machines together for multiplayer Thetawave.

Assembling the Machines

With the all of the parts in, I was able to assemble the enclosures for the two arcade machines. I assembled the first one myself and it came together relatively easily with me only recording a few minor changes that I would make for a future revision. I had some friends of mine assemble the second one and was able to identify some steps in the assembly process that may be challenging for people who have less experience than me with assemblies like this. For example, I used lock-nuts to fasten the center parts in the arcade enclosure to the side panels. This can be a bit tricky to install especially if you don't have an exact sized wrench that fits them and are instead using pliers. I may consider changing this out for wingnuts with Loctite for future revisions.

The assembled enclosure of the new arcade machine.

Now all that was left was to wire the machines. By far, the vast majority of the wiring was for the input panels. In order to make custom input panels for different games, I used a Brook Fighting board, which has terminals to connect buttons to that are coordinated with different XBOX controller inputs. The Brook Fighting board is viewed by the computer that it is attached to as an ordinary XBOX controller and passes the inputs attached to it as the their corresponding XBOX controller inputs. In order to easily connect a variety of input panels with different layouts, I chose a connector that had enough pins for every possible XBOX input to use a standard connector. Then for each input panel, I wired the all of the buttons and joystick directions to their corresponding pin position to connect to the Fighting board.

All of the other components were relatively simple to wire. The speakers were connected to the display driver board to play the audio signal that was passed through HDMI. The display driver board was connected through HDMI to the dock. The Brook Fighting board was also connected to the dock with a USB cable. The whole arcade cabinet was powered with a 12V power supply which directly powered the display and the fan. In order to charge the Steam Deck while it was connected to the arcade I bought a module to convert the 12V to USB C power delivery to power the dock. Once wired the back panel can be screwed on with four thumbscrews, while making sure to pass the connector for the dock out the hole in the panel to be connected to the Steam Deck. The final steps were to apply the magnet decals to the sides and the acrylic screen protector. With both cabinets completed, I was ready to present them and Thetawave at Open Sauce, at this point, my plan was to use an HDMI splitter to duplicate the display on both cabinets for multiplayer Thetawave, however as the event was approaching I was met with a new challenge to get a different game on the second cabinet.

A Final Challenge

A couple of weeks before Open Sauce 2024, I met Joanna, the founder of Chickensoft, an organization that creates tools to help people efficiently make games with Godot. We quickly became friends and decided to collaborate on putting the Chickensoft game demo onto one of the new arcade machines I was building. I decided to use a Beelink SER6 mini PC that I had in my shop, as its AMD Ryzen 7 7735HS could easily handle the game. With the hardware settled, the next challenge was figuring out the controls.

The Beelink computer being used to run the Chickensoft game demo on the second arcade machine.

The Chickensoft game demo is a 3D platformer, similar to Spyro the Dragon, Banjo-Kazooie, or A Hat in Time, meaning it required controls for movement, jumping, and camera manipulation. Finding the right inputs for this type of game proved tricky. For the 3D camera, we needed a two-axis analog joystick. While small thumbsticks for controllers are easy to find, we wanted something larger that would fit the aesthetic of an arcade machine. Unfortunately, most joysticks larger than thumbsticks are limited to four-way digital inputs, which aren’t suitable for camera control. Eventually, we settled on using a decently sized analog joystick from Adafruit that worked perfectly for our needs.

The analog joystick from Adafruit.

Next, we needed a digital joystick for movement, ideally one with an integrated button on top to handle jumping. This setup would allow the player to keep one hand on the camera joystick while using the other for movement and jumping, without having to reposition their hand. Unlike the search for the analog joystick, we found plenty of options here, but most were too tall and would have blocked the screen. We eventually located a shorter joystick with a hollow shaft, which allowed me to design a screw-on top with a small arcade button mounted on it, neatly routing the wires down through the joystick.

The custom digital joystick that was made for the Chickensoft game demo.

With the input hardware selected, I designed a new input panel and ordered it from SendCutSend. When it arrived, we quickly assembled the hardware, hooked it up to a Brook Fighting Board, and tested the setup with the Chickensoft game demo. The results were fantastic—the controls felt intuitive, and the game played smoothly.

With everything ready, we packed up the two arcade machines and set off for San Francisco, excited to showcase our work at Open Sauce 2024.

Showcasing the New Arcades at Open Sauce 2024

This year, Open Sauce 2024 was held at Cow Palace in Daly City, a larger venue than last year’s event, which meant even more fascinating projects on display. My booth neighbors this time included the WLED project, which is open source software for controlling RGB LEDs, and another booth showcasing giant prop weapons from video games and anime.

Fortunately, the arcade machines made it to the venue in one piece this year! I set them up with Thetwave running on the Steam Deck and the Chickensoft game demo running on the Beelink mini PC. Everything worked perfectly, so I confidently finished setting up the rest of the booth before opening it to the public.

I quickly noticed that there was a lot more interest in the arcade machines this year. Attendees were not just having fun playing the games—they were also curious about purchasing a machine or learning how to build their own arcade setups and gaming hardware. The level of engagement was incredibly encouraging, and it was thrilling to see a crowd form around our booth as people lined up to try out the games.

The Metalmancy booth at Open Sauce 2024 featuring two tabletop arcade machines.

One of the biggest highlights for me was getting interviewed by Framework. If you’re not familiar with them, Framework designs and sells upgradeable laptops—they’re a company I’ve admired for a while. Their recognition of my work and the opportunity to do an interview was truly meaningful, especially since I draw a lot of inspiration from their design philosophy. They even gave us some free hardware, which I’m already planning to integrate into future projects. You can watch my interview with Framework here.

Getting interviewed about my arcade machines by Framework.

If it isn’t clear by now, Open Sauce is my favorite event of the year. Whether you’re a creator, maker, or just curious, there’s something there for you. If you plan on attending next year, be sure to stop by my booth, say hi, and try out some games!