Koopa Shell OneWheel
OneWheel Fender Cover Shell
Intro
This project began as a simple idea: turning a OneWheel fender into a Koopa shell. The design was modeled directly in CAD, scaled to fit standard 3D printers by splitting it along natural seam lines. The shell is assembled with hot glue, making it sturdy enough for light use but safe to break apart in a fall. The final result is a fun, oversized prop that always gets a laugh. Digital files and physical prints are available through my partner’s Etsy shop, with strong community support helping to keep the project alive and thriving.
Concept Origin
This one almost doesn’t need an introduction. The moment I looked at a OneWheel fender, I immediately saw a Koopa shell just waiting to be built. It was one of those projects that shows up in your head uninvited, sets up camp, and refuses to leave until you make it real.
I couldn’t not do it.
Design & Development
The design process was pretty straightforward. I started by modeling the rough dimensions of the OneWheel tire and side rails. From there, I built the Koopa shell on top, directly in CAD.
The real challenge wasn’t the shell design, but the **scale**. It’s huge. There was absolutely no way it was going to fit on a single print bed, especially if I wanted people with standard printers (like a Prusa Mini or i3) to be able to make one themselves.
To deal with that, I split the shell along its natural seam lines, which helped disguise the panel transitions. The result is a large prop that feels cohesive when assembled, even though it's printed in chunks.
Prototype & Build
The Digitron project yielded several significant results:
Prototype and Build
This is a physically large and kind of ridiculous object. It takes a long time to print, eats a decent amount of filament, and it’s… well, spiky. Also, you're straddling it while moving at over 20 miles per hour.
So yeah—maybe don’t make it _too_ strong.
To keep it fun (and not hazardous), I used hot glue to hold the panels together. Hot glue is perfect here: strong enough to survive some light bumps, but soft enough to fail safely if something goes wrong. If you fall and land on it, the shell breaks apart instead of sending you to the ER.
Final Result
The final prints still make me laugh every time I see them. The build came together quickly, the outcome is genuinely funny, and it always gets a reaction.
I think that’s the whole point.
This project’s had more life than I ever expected. My partner runs a 3D printing business and has been managing the digital side of things for years. Over time, we’ve had a few incidents where someone (either carelessly or intentionally) bought the files and tried selling physical prints without checking with us first.
We’re not against that kind of thing in fact, we offer commercial licenses regularly and are happy to work with other makers. But businesses need communication. All we ask is that people reach out and set up something official.
Thankfully, the community has been amazing. People flag knockoff listings, let us know when something seems off, and generally don’t participate when it looks like someone is selling our designs without permission.
I don’t think I can express how encouraging that is. For fun, silly projects like this, a lot of the motivation comes from a place of _“because I can”_ and a desire to share something goofy with the world. That motivation is fragile. The fastest way to kill it is seeing someone try to profit off your work without even saying hello. But having the community support us? That helps more than I can say.
If you want one, digital files and physical prints are available through my partner’s Etsy shop.
