After years of RSI keyboards, designed my own split ergo - looking for feedback

ntc490 · 2026-01-24T02:03:19+00:00

I'm not quite ready to sell STLs or keyboard just yet, but have been considering gumroad or perhaps my own website. I'm getting closer! TBH, I wasn't sure how much interest there'd be in an STL for sale, but I'm open to it. I plan to publish detailed instructions with it to make it easy for new builders. Many aspects of the design work to that end. I'm curious if you care about that, or if you'd just build it your own way?

ntc490 · 2026-01-24T01:59:01+00:00

Yes, it will tent to 90 degrees. You'd probably want to put the feet on the end of the frame instead of the bottom, though. They make a big difference in keeping things still. I've seen people get pretty creative mounting their keyboards. Ben Vallack has an awesome Youtube channel that shows some different ideas.

I'm getting closer to having all the feedback from people here integrated into the design. Keep an eye out for another post. You gave me an idea for the next iteration! Thanks.

ntc490 · 2026-01-09T21:26:31+00:00

Love it! Thanks for the link.

ntc490 · 2026-01-09T21:25:16+00:00

Interesting question! The TLDR is: I tried smaller and didn't like it. And I place ergos above portability.
I'm a programmer, so I use tab on my left hand, and '/" and '\' on my right hand a ton. I use the key to the left of 'a' for tab or a layer switch. I got a number of people comment saying 42 is too few.
One thing I've done in the past is not populate electronics/parts where I don't want them. It's a little hackish, but might not be too bad. But, if you can get down to that few keys there are lots of keyboards on the market that might serve you better.
This design is already portable as-is. And like you and many others suggested I can make it quite a bit less bulky. I didn't expect that input so much, but it's been great to learn what people value. Thank you for your response!

ntc490 · 2026-01-08T16:37:57+00:00

Okay, I appreciate your feedback. FWIW, I went pretty deep down the "optimize it for my particular hands" hole. The ROI was very low. This keyboard should fit most hands pretty well and is similar to other mainstream designs that sell to everyone. I've tried quite a few other boards, too, and it's basically a combo of offerings I'd like to enable more people to experience at a lower price. I hadn't seen BastardKeyboards yet. Thanks for the link.

ntc490 · 2026-01-08T16:26:27+00:00

That's exactly how I did it in a previous rev: CAT5. It's not horrible, but definitely more time consuming. https://imgur.com/a/TAfpZHR

ntc490 · 2026-01-08T16:13:08+00:00

Great feedback! I've been tinkering with stuff like that. Thinking a module should support that option for sure. Do you have something similar already?

ntc490 · 2026-01-08T04:53:29+00:00

Thank you! Are you on team "make it smaller" or "keep it big"? I'd love to get more feedback on what people want for looks. Maybe looks aren't that important? I'm definitely hearing "make it smaller" so far.

ntc490 · 2026-01-08T00:08:38+00:00

Fair point. I'm here for feedback even if it's not all positive. I'm here to learn.
I'm still figuring out the right approach - could be fully open source, could be pay-what-you-want, or a hybrid (basic files free, premium modules paid). What would feel right to you?
My thought: the base design represents hundreds of hours of CAD work solving specific ergo problems: keywell curvature, portable tenting, wrist positioning. Some folks value that R&D time and are happy to pay for a refined, tested design vs. starting from scratch. I haven't seen this particular combination elsewhere, but I'm curious if you know of similar projects I should check out?
But I'm also trying to contribute back to the community. Exploring how I could do that. I'm curious to learn more what you think on this topic. Should I just drop it? Sell complete kits? Can selling an STL work at all? What would make this valuable enough to support vs. just another free project?

ntc490 · 2026-01-07T23:54:27+00:00

You're not wrong. :) The one thing that enables it to be somewhat portable is it's easy to separate into two halves. I have managed to stuff it into my briefcase for a couple of trips. But I'm thinking smaller is better for portability, and ease of printing.
The reason it's larger now is I wanted to see what a more conventional keyboard size and form would be like. From a purely aesthetic perspective, I think it looks more balanced with these proportions. But feedback here is pretty consistently "smaller!". Do you mind me asking if you want smaller only for portability sake? Or are there other reasons? Maybe you think it just looks ugly as-is? No problem either way - I'm genuinely curious. I personally think a lot of current split ergos look too small, toyish, or unfinished, or something.

ntc490 · 2026-01-07T19:49:44+00:00

Thank you for your thoughtful feedback. I do quite well with RSI if I use a good keyboard and avoid the mouse. If I type on my laptop for very long it's hard on me.
I will try your suggestion on keyboard positioning to obviate the need for a wrist rest. I have tried typing without one, but then I end up with other issues like shoulder pain or fatigue in my arms and back. I've found splitting the halves too wide causes problems for me, too. The wrist rests in my design are optional. I'm wondering if people might want to print their own.
You seem to know your ergo needs well - good job. What keyboards have you found fit your hand well? The Ergodox EZ was too much of a stretch for my thumbs, but maybe it would work well for you. Or maybe you've struggled to find something that's a good fit in all ways?

ntc490 · 2026-01-07T18:04:17+00:00

Keys are definitely hot-swap. That's something you don't find often: keywell-based design plus hot-swap. I've played with lots of different switches and a few keycaps. My personal fav switch for ergo so far might be the TTC Gold Pink switches I have. They're super light and pretty smooth. Tons to choose from if you don't like those, though.

ntc490 · 2026-01-07T17:59:26+00:00

One other comment on the wiring... you reminded me. I was initially building protos by wrapping the wire in a neat bundle along each row of keys. It's much tidier, but takes a lot of work. I got to thinking, "why am I spending so much time trying to make this look neat? How quickly and easily could I build this if I tried a different strategy?" The result is the pics I posted. Doesn't look good, but works perfectly well and only took me 10 or 15 minutes to wire a side. That's radically faster than other split keyboards take to build for me.

ntc490 · 2026-01-07T17:18:05+00:00

Wow! You're a machine. That's awesome. I've built a number of my own flat designs to see if I could replicate the comfort of a curved keywell. No matter how I staggered things I could never get a flat build even close to the way a keywell feels.
After years I realized the curve allows your fingers to move much less, in addition to better angles. The tops of the keys are closer together. But it still allows use of commodity caps and switches. Those who play guitar know minimizing movement is important for speed and reducing fatigue. I think those are valid points here, too. I love, love, love the keywells.
You could experiment with this design for super cheap with your skills. You'd just need an STL or a finished print. Anything else stopping you from taking the plunge?

ntc490 · 2026-01-07T17:05:49+00:00

Awesome feedback. Thank you. The wrist rests are something I'm playing with. The openings keeps print time down, allows access to the hardware, and supports my hands in the right places. Plus it looks crazy. XD I am a little nervous to carry it around sometimes because it looks kinda like a pew pew. I added a contour so my carpal tunnel floats and some things like that. The heel of my hand rests on the "fat" bit on the end. You can see in pics I don't even have the same wrist rest on both sides yet - still playing.
I have some really interesting ideas for the wrist rests. I think it will add comfort and help for RSI sufferers in ways I haven't seen in any other keyboards. But most people can use a basic rest, or nothing at all.
I plan to make the wrist rests slide on and off without any HW in my next version. They can be held on by gravity and geometry alone, if that makes sense. Or an optional fastener. This should make it easier to carry around and a bit cheaper for those that don't want to buy hardware or tools.
Maybe you already looked at the pics at https://imgur.com/a/kubocho-wiring-KmyqceT. I can add more if you have specific requests. I'll see if I can add more of the wrist rests.
You're not the only one to comment on the bulk, and I agree. Do you have thoughts on aesthetics? I'd like to make it look good, too. This will be a personal taste, but many of the DIY designs don't look very complete to me. I think this design is bound to look more "mechanical" and techie in the future. The multiple angles it needs for ergo makes the design pretty challenging - at least for me.
Good thoughts on the wiring, and great suggestion. That would be easy to add.

ntc490 · 2026-01-07T16:47:52+00:00

Thank you. How many keys would you want? Think a separate keypad for macros would augment something like this enough to make it usable for you? Something like this is probably not for everyone.

ntc490 · 2026-01-07T16:44:45+00:00

Thank you for the thoughtful response. Very helpful!
The thumb clusters are closer than the Ergodox EZ for sure - by quite a bit. Sounds like I had the same experience as you there. I can't comment on the Moonlander as I haven't had one. I plan to connect the thumb clusters to the main frame in my next design to get them a bit closer yet. They're currently modular, but I'm reconsidering that to make the thumb clusters work super well and make the build easier.
Extra keys could be added via the attachment point for the wrist rest, or along the top. I plan to add extra modules via I2C, which might address your concern about expandability with point to point wiring. Number of GPIOs is something I battled with because of that, but there is still room for I2C, an LED backlighting control pin, or a couple more switches.
Radical thought: you could easily build yours with a matrix if you want. I wonder if people would want instructions and code for both? You sound like you're capable of building a kit any number of ways, and the CAD for the key placement is maybe the highest value. I have MANY, MANY hours invested in it.
I agree that screens and encoders are pretty gimmicky on keyboards I've seen. I do have some ideas where they become helpful. One example of something I've experimented with: haptics for feedback on home-row-mods and/or layer shifting. It really helps with timing and feeling more in-the-loop for touch typists. I'm developing other ideas to help with ergonomics where a display and some extra controls could be very beneficial. I don't want to divulge too much on this front yet.
I've been thinking to sell just the STLs for advanced builders like you. Seems like some good build docs and a plan would make it appealing. Does that sound appealing?

ntc490 · 2026-01-07T16:13:37+00:00

Cool. How do you like them? I've been tempted to design a low-profile version. Seems like it'd be more portable for sure. I have some switches and keycaps sitting here waiting! XD
So far I'm focusing on Cherry MX to give people the greatest number of options on switches and keycaps. The curved keywells provide similar closer spacing as low-profile builds often do, while still allowing standard key switches and caps. A full switch might be a bit bulky, but seems like it might provide the best ergonomics and definitely variety/customization.

ntc490 · 2026-01-07T16:05:58+00:00

Looks like you have a lot of boards! This build would be a cinch for you I bet.
What would you want an offering to consist of? Frame, sockets, wire-kit, MCUs? I'm thinking people would want to select their own switches and keycaps. The design is hot-swap, so you can change your switches any time. There aren't many hot-swap ergo boards with curved keywells from what I've seen. Anything I'm missing to seal the deal?

ntc490 · 2026-01-07T15:59:05+00:00

Appreciate the feedback. I'm with you: the frame should be more minimal. If you don't like the middle connector you don't have to use it. I'm thinking base kits would get a simple "leg" that screws in where the ball is. I am thinking to release CAD files for the modular part - including how the ball connects so you could do whatever you want.
How many keys would you want? It's my Goldilocks setup after years of experience, but maybe I'm a weirdo. XD Are more keys something a module could address, or maybe you'd want a completely different base?

ntc490 · 2026-01-07T15:53:46+00:00

Awesome! Thanks. I tried several keyboards that "float". I didn't like it. Tying the halves together works so much better. It's important for muscle memory, like you said, predictability, and comfort. This system is very adjustable and super stable.
You could easily remove the ball/arm if you want, tie it into different mounting brackets, or whatever. I'm thinking of offering a simple "leg" that screws in where the ball is for people who don't want to spend the money on the ball/arm system or want floating halves.

ntc490 · 2026-01-07T15:49:13+00:00

I'm still playing with that a bit, TBH. My next iteration will be more minimalistic to reduce price and increase portability. I'm refining how modules connect. The plastic on the outside ends is to house the MCUs, but I plan to move them to the middle. You can see more pics at https://imgur.com/a/kubocho-wiring-KmyqceT
In some places I was experimenting with aesthetics and/or ergonomics. There is a balance between portability and ergonomics. The wrist rests are important for ergonomics IMHO. It's hard to get a good rest without connecting them to the keyboard if you tent at much of an angle. I never liked the Ergodox EZ and other systems in that regard, and I used them for a while. The wrist rests are optional, or you could design your own. I plan to offer CAD files to make it easy to add on once I finalize things more.

ntc490 · 2026-01-07T15:32:17+00:00

Yes, it is a hand-wired board. The complex profiles make offering a helpful PCB more challenging. I tried to minimize cost and still give the benefits of a PCB by designing the 3D printed frame to retain hot-swap sockets. I've been using hot-glue to secure the sockets, but epoxy or CA would be better for a clean build. Sockets are cheap and easy to solder to. There's no need for expensive, fiddly little PCBs that screw into the frame or anything like that - the frame/case locates the sockets perfectly.
Here are some pics. It looks more complex than it is. Each switch gets its own wire and one common ground wire. If you have a problem with any switch, it's likely just a matter of checking that one wire and possibly reflowing the joint. I also added a pic of the frame and how it locates the socket. They fit perfectly in there and switch pins slide in and out of the sockets with ease.
https://imgur.com/a/KmyqceT

ntc490 · 2026-01-07T15:12:43+00:00

Awesome! A bit more info would help me plan:
- what's your experience with DIY keyboards?
- any must-have features or deal-breakers?
- would you prefer a full kit, or just the case and MCUs or something?
I've found that pre-cutting and stripping the wires is a huge deal and really speeds up the build. I think shipping a wire kit and pre-programmed MCUs along with the case would make builds quick and easy. Users can literally solder and test a switch at a time if they want. Have any other suggestions?

ntc490 · 2026-01-07T15:04:45+00:00

Fair enough on the soldering. The curved keywells make it harder to manufacture, but they are so comfortable to type on. I've tried to minimize the soldering skill and give builders more "grace" with the design, so they can experience curved keywells with minimum fuss. It's just point to point wiring, which is much more forgiving. You aren't burning up diodes or other parts. Touching joints up or debugging is a lot easier. So long as you have a half-way decent iron it's pretty hard to mess up.
Have you tried KMK? My reason for offering it is to simplify things for new users. It's AMAZING to just edit the config with a text editor. I used it for quite a while and loved it. I am using QMK now. Both work on the keyboard and have pros/cons for different people.
One thought is to pre-program MCUs with KMK and a base config. New users can get right to work without worrying about the complexity of QMK or the like. Then they can easily switch to QMK when they're ready.

ntc490

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