Custom Keyboard Spotlight: Building a CA66 Keyboard

By Ryan Whitwam

A retro-inspired board with modern features.

There are plenty of keyboards you can purchase pre-built that get the job done, but the genuinely distinctive boards require a bit of work to assemble. I evaluate numerous factors before embarking on a new keyboard build project. I consider the layout, how it will jive with keysets I have and will have in the future, and what firmware it runs. Sometimes, a keyboard just looks so neat that I throw caution to the wind. That was the case with the CA66, which I just finished building recently. Here's a look at my latest keyboard project.

The CA66

It's amusing that in smartphones, designers are doing everything they can to minimize bezels, but it's the opposite with keyboards. Big bezels are very in right now because they let you create a more distinctive shape and do cool things with materials. These boards can look a bit retro, but in a good way. That's the case with the CA66—the Avec Corniche 66. That roughly translates from French as "66 with a ledge."

The board has a large, rounded top and bottom bezel with a compact 65% layout. That means there's no number pad or function key row. The arrows and far right side column of keys are also slightly offset from the rest of the board, too. The CA66 is loosely based on the IBM PCJr keyboard, which was a terrible keyboard with an interesting layout. The CA66 is a delightfully retro slab of metal—it even replicates the PCJr "IBM" badge in the lower left corner with a stylish CA66 brass logo.

I saw pictures of the CA66 from a small Chinese group buy last year, and I immediately knew that I wanted it. I had to wait several months for the second round to open for US orders, and then came the interminable multi-month wait for production and shipping.

Switch modding

Since the CA66 is a retro-inspired design, I figured why not go with a "retro" switch? The Cherry MX Clear switch was first produced back in the 1980s, and you can still find it on keyboards today. This is a heavy tactile switch that is a bit unusual in the way the force ramps up near the bottom. This switch bottoms out at almost 100g, which can be a little fatiguing if you're a heavy typist (you're not really supposed to bottom these switches out). They're also a little scratchy.

Disassembled MX Clears.

The great tactile bump of the Clear switch has led some keyboard enthusiasts to mod them with different springs and lubricant to minimize the roughness. These are called "Ergo Clears." There are newer switches that do an excellent job of replicating some aspects of the MX Clear with varying spring weights—for example, Zealios. I already have several Zealio boards, so I wanted to try something a little different. I decided to make some Ergo Clears.

The first step was buying a bag of MX Clear switches. That was easy enough. Then, I had to pick a new spring weight. I know from using other switches that I like springs that bottom out between 70 and 80g for typing. I was able to find some 72g springs, which splits the difference between 67 and 78g Zealios.

Many switch lubricants are a mix of two different Krytox materials—a grease and oil type lubricant. This is easy to mix up yourself with tubes purchased from Amazon, but the two materials slowly separate over time. I was able to find a switch lubricant called Tribosys 3204 that has similar properties and is a single material. I also picked up some thin Krytox oil for use only on the springs.

Modifying nearly 70 keyboard switches could best be described as "tedious." First, I had to open the housing (there's a top and bottom section) and remove the stem and spring. I added a drop of Krytox oil to each end of the new 72g spring, and dropped it in the housing. Next, I applied a thin layer of Tribosys 3204 to the rails on the left and right of the stem. The stem sits on top of the spring, and then it's just a matter of clipping the top of the housing back on to push the stem down into the track.

The finished switches retain the robust tactile bump of the MX Clear but with smoother action and a lighter bottom out feeling.

Building and programming

I've come to expect a few niceties with high-end mechanical keyboard kits, but some of those are missing in the CA66. That's what happens when you make decisions based almost entirely on how something looks, but I knew that going in. The switch plate, for example, does not support removing the switch tops. That means you can't fiddle with the switches after plugging them in. That makes repairs and modification more difficult. On the plus side, the manufacturer offered a brass plate option. If you ever find yourself building a custom board and brass is an option, get it. It adds good heft, and the bottom out sound is pleasantly muted compared to aluminum or steel.

The first step in building any board is to check the PCB for obvious signs of damage. You'll also want to figure out which way the switches face so you can plug them into the plate. I always have to remind myself to slow down at this point because there's one very, very important step that can ruin your day if you forget. Most boards have PCB-mounted stabilizers, and you must attach those to the board before anything else. For the CA66, I used authentic Cherry stabilizers from GMK in Germany. Do not buy the cheap Chinese knockoffs. The real deal sets cost about $10, and they're worth it. Stabilizers keep longer keys like space and enter level as you press them, and cheap stabilizers wobble and make noise. Yuck.

With the stabilizers in place, I was finally able to line up the plate and switches with the PCB. It can be annoying to get all the contacts through the right holes, but you'll get there. It took me about five minutes with the CA66. I also used some keycaps to verify switch placement and spacing. This can save you a lot of pain down the line, so I always do it even though it takes a few more minutes.

With the switches in the correct places, the time came to solder. This process is the same on almost all keyboards. The only difference here is the CA66 has a breakout board with the USB port on it, which connects to the PCB with a ribbon cable. I took that off and set it aside to avoid damage. Each switch has two solder points, so the CA66 required north of 130 total points. I always solder the four corners and one switch in the middle, and then I plug the PCB into a computer to make sure it's detected. Everything looked good here, so I forged ahead. You just need about a second of heat on the pin and PCB pad before introducing the solder. It shouldn't take more than a few seconds to get enough melted into a small cone shape.

The partially soldered PCB.

The CA66 is what's known as a top-mounted keyboard. That means the plate with the switch and PCB mounts to the top of the case. I used the eight included screws to secure the plate and screwed the bottom panel on to close the whole thing up. I also reconnected the USB Type-C breakout board and mounted that inside before sealing the chassis.

Programming the CA66 was a bit of a mixed bag. There's an online visual editor, but it's mostly in Chinese. Google Translate helped here. It runs the TMK firmware, which is not my favorite as it's somewhat limited compared to more modern options like QMK. Still, it was quick enough to tweak the layout and add some function layers.

To flash a layout, you place the board in bootloader mode by plugging it in while pressing Escape. The only tool provided to flash the board is a Windows EXE, and it's also in Chinese. There are only a few buttons, so I was able to sort that out after a few trial clicks.

Wrapping up

I didn't encounter any major bumps in the road with the CA66 build. The board looks every bit as fantastic in real life as I'd hoped, and I enjoy typing on my modded Ergo Clears. I decided to put a keycap set on this board called GMK Carbon, which matches the black anodized case quite well. It's based on the colors of the HEV suit from Half-Life, hence the lambda key. The little turtle is an artisan keycap called a "Snapper."

I was surprised how many options I have with the LED light strip. I'd only seen pictures of it in rainbow mode, but you can choose any color thanks to the bank of RGB LEDs on the PCB. There's a diffuser tucked in the case to make the lights look nice and smooth. I have them set to "Carbon orange" right now. Overall, this is one of my favorite boards right now.