Small Space. Big Ambition. Coleman Martin's Atom Pinball.

"My wife said we have room for four pinball machines in the basement. But there was this lonely little corner…."

That's how Coleman Martin from Kansas City ended up building Atom — a micro pinball machine packed with innovation, magnets, and music he learned to compose from scratch.

At Pinball Expo 2025, Coleman wheeled out what might be the most densely engineered homebrew game on the show floor. Not just because of the physics. Because of what it represents: what happens when you combine curiosity, 3D printing, and a basement corner that "maybe could fit something small."

3D Printed. Almost Everything.

"I was working on a larger machine and developing a mini playfield for it," Coleman explains. "The mini playfield became kind of its own game."

So he leaned in. Hard.

The entire cabinet? 3D printed. Ball guides? 3D printed. Ramps? Mechanisms under the playfield? 3D printed.

What's not printed: pop bumper mechanisms, flipper assemblies, the spinner. Coleman stuck with precision flippers — "I wanted to make it play nice and look nice" — and the decision pays off. The game feels tight. Responsive. Real.

The playfield itself is wood wrapped in prismatic car vinyl, giving it a shifting rainbow hue under the lights. Coleman's planning a final version with printed art on that same vinyl, plus a proper clear coat. But even in prototype form, Atom turns heads.

Electrons, Protons, and Magnets

The theme is atomic physics, and the playfield mechanic delivers on it. You've got an electron in orbit. A proton locked at 12 o'clock. And a magnet that grabs the ball mid-flight.

"The magnet sets up shots for the red flipper," Coleman says. "Otherwise, trying to hit the drop targets and ramp is random. But with the magnet, you can really aim."

Hit all three drop targets. Light the electron orbital. Shoot under the red flipper for atomic multiball.

There's also an accelerator energy countdown — if it hits zero, you lose your ball. Coleman added it to prevent someone from starting an electron orbit and walking away. "I didn't want the whole thing to melt down an hour later."

Smart design. Practical problem-solving. That's homebrew in a nutshell.

Music, Lessons, and Scott Danesi's Influence

Coleman's first game, Greek Gods, featured a transparent LCD screen. Players look down through it into an underworld mini playfield where they can redeem their soul for an extra ball. Wild concept. It worked.

But Atom upped the ante in a different way: Coleman did all the music himself.

"One of the things that made me confident I might be able to build a homebrew was Scott Danesi bringing Total Nuclear Annihilation to Expo years ago. He did the music for that too."

So Coleman started taking music lessons. First on a Teenage Engineering OP-Z for Greek Gods. Then he upgraded to an Ableton Push 3 for Atom.

"This music is done in Ableton. It's not my final music — it's not great — but it's definitely a step up from the work I did before."

Coleman's being modest. The fact that he taught himself music production for his pinball games is the kind of commitment that defines the homebrew community.

Iteration is Everything

The playfield is on its third form. "Many of the shots were too hard on the first version, so I moved the ramp, moved the flipper shot, reprinted a bunch of pieces."

Coleman designs in Fusion 360, prints the parts, screws them to the playfield, and tests. If something doesn't feel right, he iterates. No ego. Just improvement.

He also learned something important bringing Atom to Expo: people really like to nudge.

"That's one thing I learned taking it to Expo this year — how much people will nudge the table to try to keep from draining."

Good thing the whole machine sits on a rolling wooden table with casters. It lets you nudge. The P-ROC board has an accelerometer built in. Coleman could turn it into a tilt, but for now, he's keeping it loose.

The Heart of Homebrew

Coleman credits the Multimorphic Slack group and Scott Danesi's encouragement for giving him the confidence to start building. "Scott was super supportive to everybody building their homebrews."

That's the spirit of this community. Learn some woodworking. Learn some electronics. Take music lessons if you have to. Build the thing.

Atom isn't just a pinball machine. It's proof that you don't need a factory to make something beautiful. You need a corner in the basement, a 3D printer, and the willingness to print version three when version two doesn't feel right.

Coleman's already thinking about the next one. But first, Atom needs a few more tweaks, some final art, and a proper clear coat.

Then it's ready to keep spinning that electron — and keep inspiring the next builder who walks by and says, "Wait. You made that?"

Want to build your own game? Check out this blog post for more info on how and where to get started: https://www.marcospecialties.com/pinball-parts-blog/homebrew-loot-crates