Leonardo KeycapRio brings flexible tented ergonomics to a compact MX keyboard

Leonardo KeycapRio makes tented ergonomics look approachable

Leonardo KeycapRio goes straight at one of the biggest assumptions in ergonomic keyboard design: that a tented unibody has to be fiddly, hardware-heavy, or awkward to assemble. Stephan Møller’s compact MX board answers that with a screw-free, glue-free build, using the PCB itself as part of the structure instead of hiding it under a complex case stack.

That is the real hook here. KeycapRio is not just another small ortho-adjacent board, it is a 30-key, 5x3+1-ish monoblock split MX layout that tries to give you split-like angle and desk presence without separating the board into a traditional two-piece build.

A flexible PCB doing structural work

The standout engineering choice is the custom single PCB, which includes deliberate squiggles so it can bend without cracking when mounted to the tenting base. That detail sounds minor until you think about what it solves: the board can keep a connected unibody shape while still adopting the kind of angle many builders chase in split ergonomics.

Instead of relying on a complicated case sandwich, the PCB is press-fit onto a 3D-printed tented base. That keeps the assembly simple and makes the whole project feel more attainable, especially for builders who already know their way around hotswap parts, a Pro Micro-style footprint, and the usual open-source controller ecosystem.

Compact, but still very much a real keyboard

KeycapRio sits in the compact ergonomic lane rather than the full-featured typing-board lane. With 30 keys, it is clearly designed around a focused layout, one that expects layers and efficient movement instead of raw key count.

Even so, it does not read like a sculpture or a one-off concept prop. The board is hotswap, uses an RP2040 Pro Micro controller, and supports ZigMkay firmware, so the practical side is very much intact. That combination matters because it lowers the barrier for anyone curious about a one-piece ergonomic board without forcing them into an exotic electronics setup.

Why the screw-free build matters

The phrase that lands hardest is simple: no screws, no glue. In hobby terms, that is a big deal because it removes two of the most common friction points in a custom build, extra fasteners and permanent assembly steps.

A press-fit tented base makes the build easier to imagine, easier to finish, and easier to revisit later. For anyone who has put off a custom ergonomic project because it looked like too many parts had to line up perfectly, KeycapRio offers a different message: the geometry can be clever without the assembly being punishing.

Part of a bigger Stefan Møller experiment

KeycapRio also makes more sense when you place it alongside Stephan Møller’s recent work. Wilson26 appeared on January 20, 2025 as a 26-key semi-handwired split keyboard using 1u PCBs and Seeed XIAO controllers, with magnets helping hold the case together and keep the halves planted on the desk. Mike Typeson followed on August 26, 2025 as a 30-key true split keyboard held together by a 3D-printed tented base, even though the electronics are in three pieces.

Then came Clacky Chan on September 22, 2025, a true split prototype with custom tenting and Stephan Møller’s ZigMkay firmware. It used a hotswap RP2040 Pro Micro controller, a reversible PCB, and a diodeless design, which makes KeycapRio feel less like an isolated experiment and more like the next step in a clear design sequence.

What the project says about open-source ergonomic keyboards

On Møller’s GitHub profile, those projects sit together with repositories such as wilson26, mike-typeson, zigmkay, and clacky-chan, which shows a body of work built around compact ergonomic layouts and firmware as much as around case design. The thread running through all of it is obvious: tenting, unibody construction, and open-source hardware are being treated as one conversation instead of separate problems.

That is where ZigMkay becomes important too. It is an open-source keyboard firmware written in Zig, designed to run on keyboards with MCUs supported by the microzig library. In practice, that helps KeycapRio stay inside a DIY ecosystem builders already understand, rather than pushing them into a dead-end proprietary stack.

Why KeycapRio stands out in the ergonomic crowd

The broader ergonomic-keyboard world often treats monoblock and split-style boards as niche curiosities, especially when the layouts get small and the tenting gets ambitious. KeycapRio pushes back on that by showing a compact unibody can still be buildable, mod-friendly, and logically engineered.

The result is a board that takes the visual drama people expect from tented ergonomics and pairs it with a very practical assembly story. By letting the PCB flex, press-fitting it into a tented base, and keeping the electronics friendly to hobbyists, Leonardo KeycapRio makes the case that compact one-piece ergonomic MX boards do not have to feel like a compromise. They can be the cleanest path to a desk-friendly build that still looks and behaves like something made for enthusiasts.