Custom Mechanical Keyboard

Built in 2019

The world of mechanical keyboards is surprisingly deep. On a surface level, most people don’t even draw a distinction between common membrane/rubber dome keyboards and mechanical keyboards. When a typical keyboard may cost around $20, it may seem strange that some people would voluntarily spend $150-$200 on a mechanical keyboard. It’s downright crazy to most that one might be willing to pay upwards of $500 or even $1000 for a custom keyboard that “does the same thing”.

That is the world of custom mechanical keyboards. It’s no longer about pure utility, but rather it increasingly centres around the satisfaction that results from a premium typing experience. After hearing what a premium keyboard can sound like, I set out to build my own. This started a period of research, gradual purchases, long waits, and eventually the final build and first typing test.

By the measures of the custom keyboard community, my keyboard is actually quite modest. Let me break it down.

A mechanical keyboard generally has four major parts:

1. The case. This is the outer enclosure that holds the other parts. There may or may not be a plate, which I’ll explain in the build breakdown.

2. The PCB. All the electrical stuff happens here.

3. The keyswitches. This is the most important component, as the feel and sound of the keyboard is mostly dictated by the switch.

4. The keycaps. The case and keycaps together determine the look of the keyboard.

The Case

The case I used is a black-anodized 5-degree aluminum case from KBDfans, a Chinese keyboard part supplier. I also bought an aluminum switch plate in the same order. It’s a very basic tray-style case. The purpose of the plate is to add additional stiffness and help align keyswitches. Thin plates such as mine are quite cheap, but in high-end custom keyboards the plate can be a 4mm thick behemoth of precisely machined, hand-polished brass. Yeah, things get pretty crazy.

Within the realm of custom keyboards, this case and plate are on the low end. More expensive cases are generally heavier, have a more premium finish, and are more decorative. They are also much harder to come by, as keyboard parts are often bought as part of “group buys” (to be explained in the keycap section).

The PCB

The PCB was again a very basic one from KBDfans, called the DZ60. Like most custom keyboard PCB’s, it isn’t hotswap-compatible. Therefore, I would have to solder my switches on. The DZ60 supports a wide range of key layouts, which was essential since my layout is not conventional. I chose a layout with a “2u” left shift, meaning that the left shift is 2 times the width of a regular single key. This is in contrast with a traditional layout, where the left shift is 2.25u. This slight shift allowed me to squeeze more keys on the lower right side of the keyboard, making space for arrow and function keys.

One feature of the DZ60 is that it’s QMK compatible. QMK (Quantum Mechanical Keyboard) is a firmware toolkit that allows you to flash custom firmware onto the PCB, remapping the keys at the firmware level. I stored my keymap file on my Github.

The Keyswitches

There are generally three classes of mechanical keyswitches:

1. Linears. These switches depress with a linear force vs. displacement graph.

2. Tactile. These switches have a tactile bump partway through the stroke, allowing the typist to more clearly feel the moment when the switch actuates.

3. Clicky. These switches are like tactile switches, but they are made with an extra part to produce an audible click.

For my keyboard, I chose the Gateron Ink, a linear switch. Linear switches appeal to me because of the smoothness of motion, and the gentle “thock”-like sound they produce. Linear switches are offered with a variety of spring stiffnesses. I actually bought a switch tester that came with a variety of different keyswitches so that I could feel the difference between different switch stiffnesses. I settled on the Gateron Ink since it had my desired stiffness: 60 g to actuation, 70 g to bottoming out. Reviews also identified the Gateron Ink as being a very smooth switch, rivaling the more expensive Tealios by Zeal Generation Inc. However, there isn’t a lot of publicly available rigorous scientific testing to quantify such claims. That’s possibly something worth investigating if I ever get access to a an Instron machine or something similar.

An additional optional step that I took to prepare my switches was the application of lubricant. Although the switches come pre-lubricated from the factory, the application of additional high-quality lubricant can significantly affect the feel and sound of the keyswitch. Based on recommendations from the community, I used a lubricant called Krytox 205 grade 0. It’s a thick grease, well suited for linear switches. I would disassemble each switch, and apply a thin layer of lubricant to all sliding surfaces using a small paintbrush. The entire lubricating process took several hours. I also lubricated the stabilizers, which stabilize longer keys such as the enter key, shift keys, and the spacebar. The stabilizers are what allows you to press the left side of the spacebar and have the whole spacebar move down evenly.

Keyswitches need to be soldered onto the PCB. I didn’t have very much experience with soldering, but luckily I have friends who do. The soldering I was doing was through-hole, which is very easy. I didn’t really have any problems, other than accidentally soldering a couple switches in the wrong spot at one point.

The Keycaps

Ahh, the keycaps. I would argue that the keycaps are the most significant factor in the overall aesthetic of your keyboard. The “gold standard” of keycaps in the keyboard community are those manufactured by the German company GMK. GMK keycaps are made from doubleshot ABS, which results in a very high quality, thick keycap. The lettering will never wear away, and there is a high degree of control over all colouring. GMK keycaps are sold in group buys.

What the heck is a group buy?
When a designer wants to produce a custom set of keycaps for the community, they must go through a design process with GMK and order a minimum number of sets. However, it requires significant capital to place that order, so they go to the community with their design and ask interested buyers to put down money up front to cover the capital cost. If enough buyers are interested, then the designer (or their designated vendor(s)) places the order. After the keycaps are produced, the designer (or vendor(s)) coordinates the distribution to all buyers. Obviously this process comes with a certain amount of risk for the buyers, as there is a chance that something goes wrong and their money is lost. My advice to any readers interested in building their own custom keyboard is to research the risks involved with group buys, and only buy from reputable sellers with a history of successful group buys. This same process of group buys can apply to any part, not just keycaps.

The keyset I bought is called GMK Bento, inspired by the Japanese bento box. It has, in my opinion, a great colour combination, and cool novelty keys. It has a hiragana sub-print, though it does not serve a functional purpose other than to fit the aesthetic theme. It also supported all the necessary keys for my layout, such as a 2u shift key. I ordered the keyset in late February, but didn’t receive it until mid August due to production delays. It was a gruelingly long wait, but well worth it in the end.

Final Thoughts

Typing has never sounded or felt so good. Though it took longer to complete than I would have liked, I’m ultimately very glad that I took on this project. I use my keyboard every day, and I often stop mid-type to admire how good it sounds or how satisfying it feels. Typing on the cheap rubber-dome keyboard at the office feels downright horrifying in comparison. I would definitely consider building a second keyboard so that I can have one at work and one at home.

The number one question I get about my keyboard is “how much did it cost?”. The answer is, of course, a lot. Probably a lot more than most people are willing to spend on a keyboard. But it did result in a truly unique possession, and at the end of the day, it was worth it to me. I think that’s all that really matters.