README.org

ACK42

ACK42 is a DIY sandwich-style keyboard with 42 keys inspired by Absolem, Corne and Kyria. The first prototypes were assembled in September 2020 and they have miraculously survived daily use since then.

This repository is a dump of the artifacts left over from the creation process. Things might be broken, so take this not as a finished product ready to be sent off for manufacturing, but rather as a documented example of one way of creating a keyboard.

I briefly entertained the idea of skipping a PCB and instead 3D-printing wire channels and hand-wiring Kailh hotswap sockets (see Gallery). In the end I went the PCB route and that was a good decision in hindsight. It made assembly much easier and I ended up making 4 versions of the keyboard: 2 MX hotswap versions and 2 Choc low-profile versions, 3 of which I still use regularly, some daily.

Process (rough)

1. CAD top plate, spending countless hours shifting switch positions around a few millimeters at a time and 3D-printing prototypes until things feel just right
2. CAD everything else: bottom plate, screw holes, MCU cutout and cover
3. Dump top plate to a KiCad-friendly format so the outline and switch positions can be used during PCB design
4. Add all PCB components into KiCad, connect them in the electric schematic and then on the PCB
5. Import top plate into KiCad and painstakingly rotate and position all switch footprints so they’re lined up with the top plate
6. Add some art to give the PCB some flair
7. Export Gerber files from KiCad and send them off to the manufacturer
8. Export all necessary SVG files from OpenSCAD, tile them neatly in a single SVG file that represent an acrylic sheet and send it off for laser cutting
9. Order all other necessary components (see Materials)
10. Wait for parts to arrive
11. Assemble the keyboard(s)

Materials

All parts required to assemble a single ACK42 keyboard (MX variant):

• 1 ACK42 PCB
• 1 Elite-C microcontroller with pins + stand-offs
• 8 M3 12 mm screws
• 8 M3 cap nuts
• 2 M2 screws
• 2 M2 stand-offs
• 64 0.5 mm washers (or equivalent)
• 42 Kailh hotswap sockets
• 42 through-hole diodes
• 42 MX-style switches
• 42 Keycaps

Gallery

License

LICENSE © Pontus Andersson

The KiCad components were taken from the following repositories and their licenses can be found in the corresponding pcb subdirectories:

• https://github.com/daprice/keyswitches.pretty
• https://github.com/keebio/Keebio-Parts.pretty
• https://github.com/tmk/keyboard_parts.pretty