I did a thing: Built a Keyboard

(This is an evergreen document devoted to the construction of a keyboard)

I’ve decided to build the dactyl-cc keyboard.

• Printer
  • Prusa i3 MK3S+
  • OVERTURE PLA Matte. (fantastic!)
  • Print Time: 52 hours
• Parts:
  • Teensie2.0
  • MCP23018
  • TRRS Male-to-Male cable
  • TRRS break out jacks
  • 100 1N4148 Diodes
  • 70 Keys: Cherry MX Silent Red
  • USB-C to MicroUSB cable
• Consumables:
  • 30Gauge jumper wire
• Files:
  • left
  • right
  • bottom_left.stl
  • bottom_right.stl
  • controller holder.stl

Notes

Printing

• When printing the Loligager, change it’s position to lay flat, and print the second one in MIRROR
• I sliced with Prusa Slicer with 0.15mm layer hight, 15% infill, and build plate supports for the two halves of the keyboard.
• I’ve found no one talking about what screws to use, other than one reference to an M3. depth looks to be about 1/4"

Building QMK

Note, I tried a lot of things¹ in desperation, so all of these steps may not be necessary.

brew install qmk/qmk/qmk
brew install gcc-arm-none-eabi
python3 -m pip install -U qmk
qmk setup

# verify it worked:
qmk compile -kb clueboard/66/rev3 -km default

Discussion

Why the Teensie 2.0?
I really wanted a microcontroller that was USB-C. But, the wiring guide I had was for a Teensie 2.0, so I decided to build this incarnation with the Teensie 2. If all goes well, I might change the microcontroller later.

The big reason I wanted USB-C was for compatibility with my MacBook. But, good news! I found a USB-C to Micro-USB cable!

How great is that matte filament?
It’s shockingly great. I printed one half of the keyboard in Polaroid Black PLA and the difference was stark. The vertical pieces in the print look like they were injection molded, they’re so smooth.

Also, the support material was WAY easier to remove with the matte.

Tips on removing the support material
“When brute force isn’t working, use more brute force” - Udi Manber. I got pretty aggressive on the last keyboard half (I printed the first one in the Polaroid filament). I used

Where’s the mouse?
I’m optimizing for probability of success, so I’m tackling in stages:

• v0: use a trackpad
• v1: add a trackpoint^{2 3}

How much has this cost ?