Krtkus

An extended 5x12 keyboard with 2 extra keys. The design is intended for ortho layouts with a shifted number row, allowing for the placement of the delete and tilde keys above their usual spots. PCBs are designed in Kicad, case in Blender.

• Low profile
  • Kailh Choc V1
  • Gateron KS-27/KS-33
• QMK/VIA compatible
• Tray mount
• 3D printed case with a 7 degree tilt
• 236mm × 122mm × 30mm

Connecting the keyboard to usevia.app requires manually uploading the design file in the design tab.

My builds

Board	Keycaps	Switches	Case	Firmware
	MBK Legend Ergo/Ortho	Choc V1 Brown	Black Resin	Caterina
	Keychron LSA ABS	KS-33 Brown	JLC Black Resin	Caterina (Legacy)
	Keychron LSA PBT	KS-33 Red	9600 Resin	Caterina (Legacy)
	Keychron LSA ABS	KS-33 Brown	Black Resin	Atmel DFU
	Logitech MX Mechanical Mini	KS-33 Brown	Black Resin	Caterina
	Dell AT101W	KS-33 Banana	Krtkus Retro	Caterina

Room for improvement

• Spacebar stabilizer
• Hotswap version
• Standard USB port orientation

Parts

• One of the PCBs:
  • Choc V1
  • KS-33
• Case:
  • STL file
• Arduino Pro Micro
• 61 SMD diodes
• 61 switches
• 61 keycaps
• 5 M2x6mm screws

Optional:

• 90 degree Micro-USB cable
• Rubber feet

QMK

Standard QMK setup except for "tap_keycode_delay": 40, which fixes ignored taps in some games where input scanning is tied to frame rate. To best of my knowledge, keeping this value above 33ms (30fps) should cover all edge cases.

Documentation

• info.json reference: https://docs.qmk.fm/reference_info_json
• Keycodes: https://docs.qmk.fm/keycodes

Compiling (Windows)

• Python: https://www.python.org/
• MSYS: https://msys.qmk.fm
• Toolbox: https://qmk.fm/toolbox

Run the compile script:

python qmk_compile.py

Resetting

Once the firmware is flashed, it provides key combinations to enter bootloader or clear the keyboard's persistent storage.

• LShift + RShift + B - Puts the keyboard into bootloader mode for flashing
• LShift + RShift + C - Clears EEPROM and reverts to the default keymap

Kicad 8

Libraries

Below is a list libraries included in the project. These libraries are not licensed under CC0. Please refer to each specific library for licensing details.

• Scotto Kicad
• MX V2
• Gateron 3D models

Switch grid

Unit	Offset
Switch	19.05
Switch 4	4.7625
Switch 16	1.190625
Switch 64	0.29765625