Split Mechanical Keyboards

Do you feel sore typing on your old keyboard? Do you feel like your keyboard is holding you back from reaching your full potential? Or, do you simply want a new, shiny gadget to differentiate yourself from the crowd? Then a custom ergonomic keyboard might be something for you.

I recently fell down the rabbit hole of making custom ergonomic keyboards. For most of my career, I've never cared about keyboards or ergonomics, typing away on whatever piece of cheap plastic I found at the office. But recently I started looking for new ways to be more efficient at work, and it sort of escalated. Well, anything worth doing is worth overdoing, right?

One thing that always bothered me about standard ANSI keyboards, aside from the illogical QWERTY layout, is the weird offset between the rows. This so-called row-stagger, a relic from typewriters, is making the hand positions quite awkward. Since we are not using typewriters anymore, the row offset can be skipped entirely, minimizing lateral or sideways finger movements. To better accommodate the length difference between the fingers, a column offset can be introduced.

Frequent and prolonged typing can cause repetitive strain injuries (RSI's) and increase the risk of carpal tunnel syndrome. Making lateral finger movements can be quite a strain, and having a column-staggered keyboard can help with that.

Off-the-shelf or do-it-yourself?๐Ÿ”—

So, regarding ergonomic mechanical keyboards, there are somewhat limited options commercially available, and those that exist, like the kinesis, tend to be a bit pricey. In the open-source / DIY space, however, there are countless boards if you are willing to build them yourself. So being a nerd who enjoys a bit of tinkering, the choice was obvious.

I did a thorough bit of googling before I found Bastard Keyboards. I found the dactyl-style keyboards interesting because they had a swept design, minimizing finger movement. These designs were also open source, with the electronics, software and hardware files available on GitHub. Since this was my first try at making a custom keyboard, I wanted to try both a minimal design and a fully featured one to see what fit me best. I settled on trying the scylla and skeletyl.

Sourcing parts๐Ÿ”—

There are both pre-built keyboards and DIY-kits available on the website. Since I was planning on building several keyboards (and ordering stuff from AliExpress is one of my hobbies), I opted to source the parts on my own.


I ordered the PCBs from jlcpcb. Their quality and service are great for the price. For each half of the keyboard, there is one flexible board for the main key cluster, a smaller one for the thumb cluster, and an adapter board for the MCU. The PCBs are designed so that the same board can be used for both the left and right sides, minimizing the number of PCBs to order.



Since I don't have a 3D printer, I ordered the enclosure from jlcpcb as well. I ordered a SLA resin print that was fairly cheap, and the quality was superb. The surface finish was very fine, with the layers barely visible.



The Bastard Keyboards are mostly designed around the Elite-C microcontroller board. This is simply an upgraded version of the Arduino Pro Micro. The Elite-C has the same ATMega32U4 chip but exposes an additional 5 I/O pins on the bottom side. It also uses the Atmel-dfu bootloader instead of Catalina, which is found on Arduino boards. I opted for a cheap Pro Micro clone I found on AliExpress. The Elite-C board is designed to use QMK firmware, a popular choice for keyboards with Atmel/Arm chips. QMK is highly configurable and can be extended with all kinds of hardware like touchpads, encoders, displays and LEDs.


The Skeletyl board is quite minimalistic and uses only 36 keys. It can be used with the miryoku layout enabling a full keyboard through layers and modifiers. I found it to be well-thought-out and not too complicated. Miryoku makes use of home-row modifiers, putting the shift, ctrl, alt, and win modifiers on the middle row upon holding. This poses some challenges, though it is easy to activate them by accident by holding the keys too long. It can also be tricky to do combinations with multiple modifiers.


Since I was to learn a new physical layout for the keys, I figured I might as well learn a new key-layout as well and ditch QWERTY completely. There are several alternatives that are more efficient, like Dvorak, Workman and Colemak. I started learning Colemak-dh, which is supposedly easier to learn when switching from QWERTY. This was quite an undertaking, as I had to relearn 25 years of muscle-memory. Practicing at sites like keybr and monkeytype got me up to speed.

Keycaps and switches๐Ÿ”—

Regarding the mechanical switches, there are way too many to choose from. The switches come in three types , linear, tactile and clicky. I had once tried those obnoxiously loud blue switches and figured I wanted something more discrete. I picked gateron yellow because it has a little more feedback than the more common reds.

For the keycaps, there are multiple types as well. Since I bothered soldering all the LEDs, I picked double-shot or pudding-type caps that allow some light to pass through. Since the keycaps have a profile based on rows and are based on QWERTY, I had to place them accordingly. For the thumb cluster keys, I just put some random keys since all the keys on my board are 1U in size. Since I touch-type, this hardly matters.

Closing thoughts๐Ÿ”—

So I've made two keyboards, and I really like both of them. For typing, I found the Skeletyl board to be really nice. All keys are very easy to reach, and you barely move your hand at all. However, when doing a lot of key combinations, it can get quite cumbersome. In that case, the Scylla board is easier to use because it has extra keys for modifiers.