Some time ago, I was introduced to the r/MechanicalKeyboards subreddit, where I marvelled at the colourful and creative range of keyboards on display. Now I have four 60% keyboards, two split ergo keyboards and a bunch of bags with key switches laying around. It is an odd hobby to enjoy, for sure, but allow me to introduce it to you.
Custom Mechanical Keyboards, in sort of a nutshell
If you play games on your PC often, you probably have a mechanical keyboard, likely outfitted with one of Cherry’s famous line of switches. These mechanical switches have been favoured by PC enthusiasts over the dome switches (and membrane keyboards) found in most cheap keyboards for their tactility when pressed, their sound, their actuation speed, and/or their smooth press action. However, these gaming mechanical keyboards are generally limited to Cherry’s three most popular switch types (Red, Brown and Blue) and in full-size (104 keys) or tenkeyless layouts (without the numpad). Thankfully, a community has existed for years (probably dating back to when the IBM Model M Keyboard gained traction) that has appreciated mechanical keyboards (and other niche keyboard types), to the point of customising and creating their own mechanical keyboards. For those particular about their keyboards, they now have a wide variety of PCBs, cases, key switches and key caps to choose from (though most of these will have to be obtained second hand). Let’s go through each of these in turn.
As already noted, most people will be familiar with Cherry’s three most popular switches, the Cherry MX Blue, Brown and Red. These three represent the three main categories of key switches – clicky, tactile and linear. Both clicky and linear switches have a ‘bump’ when pressed down (where resistance to pressing the switch down builds up and then suddenly falls off), but clicky switches are specifically designed to output a click sound when pressed (though the mechanisms differ between switch manufacturers). Linear switches do not have a bump and the force required to push down increases in a roughly linear fashion (thus the name). Within these categories switches can differ greatly in feel depending on the weight of the springs within the switch, the method used to create the tactile bump, and the point at which the switch actuates (registers as a key press to the computer) when pressed down. For example, Kaihua Kailh Speed switches have an actuation point that are just over 1mm down, which will appeal to gamers who want their key press to register as soon as they press down on the keyboard.
PCB and cases
Most custom mechanical keyboards are built on a PCB with a microcontroller (such as an Arduino or Teensy) to handle processing key presses. While the more technically inclined can take a stamp-sized PCB and handwire their own keyboard, soldering wires between the PCB and the switches, most people use a PCB the size of the keyboard and mount the key switches on the PCB. Each switch has two metal legs that are pushed into holes in the PCB, which are then soldered to the contacts surrounding each hole. That said, recently Kaihua has introduced a hotswap socket that allows you to simply insert the legs into the holes without the need to solder them. As these PCBs define the physical key layout for the keyboard, there is a wide variety of PCBs for various keyboard sizes and layouts. Generally these layouts are a subset of the full-size keyboard and are designated by the percentage of keys (roughly), such as 60% or 75%. Other layouts include ortholinear keyboards, which do not stagger keys in each row as a normal keyboard does but lines them up in a grid of rows and columns, theoretically reducing the distance your fingers need to travel to type. Of particular interest to me, there are even split keyboards which have separate PCBs for the left and right hand, typically connected by a 3.5mm AUX cable.
The advantage of the microcontrollers typically used on these PCBs is that the firmware can be flashed by the user, allowing you to install a firmware with a keyboard layout that you prefer and with support for macros, customisable RGB lighting and much more. Some even let you open a text editor and push a button combination to start up a text interface for setting options on your keyboard. The most popular firmware, QMK, is an open-source firmware with prior support for tens of different PCBs and keyboard kits and allows people to relatively easily add support for new hardware and handwired keyboards.
One of the more popular keyboard sizes, the 60% keyboard that omits the function row, navigation keys and numpad from a full-size keyboard, is a mostly standard size and thus a 60% PCB can generally be combined one of the many different 60% cases available (in materials from acrylic to aluminium). But other layouts tend to be sold with their case as they are not generally interchangeable. On the topic of cases, apart from the housing that the PCB will be screwed into most cases come with a plate that goes above the PCB (or at least allow you to purchase a plate separately). Key switches will clip into the plate, making it less likely that switches will fall out of the PCB, and the plate also provides additional rigidity for the keyboard and protects the PCB from crumbs and dust falling between the key caps. For this reason, most people prefer a metal plate. Some niche cases also come with or allow you to install a weight block, which is literally only used to make the keyboard heavier and less likely to slip around on the table, or a battery for a Bluetooth capable keyboard.
The most visually distinctive element of a keyboard, there are likely hundreds of different key cap sets available by now. Key caps not only affect aesthetics however, as there are a number of key cap profiles which can influence how easily your fingers travel between keys and find the key you want to press. The DSA and XDA profile, for example, has each key cap share the same shape, resulting in a very flat and uniform keyboard. By contrast, SA, Cherry, OEM and other profiles generally have a taller key cap for the top rows of the keyboard and a concave shape when the keyboard is viewed from the side. Some say that these profiles result in less finger travel when moving between keys and easier acquisition of the correct key when typing. The profile can also affect the sound of typing, as the very tall SA keycap has a larger hollow space for a deeper sound when slammed down compared with most other profiles.
Most key caps are designed to fit the Cherry MX stem, which looks like a plus (+) sign and is used by most key switch manufacturers including Gateron and Kaihua. However, Alps/Matias switches are incompatible with Cherry-style keycaps, limiting customisation for those who favour the silence and/or feel of these switches.
Stabilisers are an essential part for most keyboards (the exception being keyboards that only use smaller length keys). These are generally used for the spacebar, shift, enter and backspace keys and are two plastic stems attached with a wire that prevent these keys from wiggling when pressed. Most prefer stabilisers manufactured by Cherry or GMK, and enthusiasts will lubricate the stabilisers to minimise noise and ensure smooth pressing action. Dedicated enthusiasts will actually lubricate the key switch internals as well for the same reasons.
Some PCBs support per-switch LED lighting, which will be installed after the key switch and also soldered to the PCB. The cable from the keyboard to the PC is also another point of customisation, and you can have someone create a custom sleeved cable in the colour(s) of your choice.
Accumulating a collection
Looking for a small keyboard I could take to work, I began with a KBParadise V60 Matias Quiet Click, a fine keyboard for typing, but limited in its ability to customise the key caps or define my own layout. The Matias Quiet Click switch has a nice feel with a defined tactile bump but also quieter than any other tactile switch I’ve used since. I moved onto the New Poker II with Cherry Brown switches, but I wasn’t happy with the key layout for function keys.
It was at this time that I saw that there was an avenue for building a custom mechanical keyboard without the need to solder anything. Kaihua hotswap sockets were not available at that time, but people were using holtite/SIP sockets to add hotswap capability to existing PCBs. These are little lead/gold cones that you stick in the holes in the PCB, and legs on switches can slip into the cones to make electrical contact with the PCB. After a little research I ordered a B.face from Winkeyless.kr, a 60% PCB with holes that support holtites, RGB underlighting and support for single colour LEDs for each switch. While the holtites for the LEDs had issues staying in the holes, the holtites for the switches were a snug fit and easily stayed in when removing switches. I pressed each holtite in with a hex screwdriver and then tapped each one with a soldering iron to make the fit a bit more snug. The switches I used were an interesting choice – Gateron Tactile Clears that are no longer available. These switches were a cheaper version of the Zealio switch Gateron manufactured for ZealPC, and were possibly manufactured without authorisation from ZealPC. At the time I merely considered them as a cheap tactile switch with a weighting heavier than a Brown, which I thought I would enjoy. Indeed, I enjoyed the tactility of the switch compared to a Cherry MX Brown, but the weighting was a bit much and exhausted my fingers over long typing periods.
A little later I was noticing some pain in my wrists when typing. I experimented first with the Diverge 3, a split ergonomic keyboard with an acrylic case. It has a number of advantages over other similar alternatives, being relatively cheap for an ergonomic keyboard with a quite usable thumb cluster that doesn’t require you to move your fingers much in general typing. However, it doesn’t provide an easy option to install tenting legs, which helps address issues with wrist pronation. I also chose the wrong key switches for my Diverge 3 – Gateron Clears, a light, linear switch. These would activate even by resting my fingers on the keyboard, and accidental presses happened too often for my liking while my fingers moved around on the keyboard.
I moved on to my current daily driver, the Ergodox EZ. A very pricy split ergonomic keyboard, it matches that value with a solid build quality, hotswappable switches, the ability to tent the keyboard, and underglow RGB lighting.