Carl-Fredrik Arvidson

Hot Swap TBK Mini

Published 2022-01-21
and modified 2022-02-20

This is the third time I'm building a custom keyboard. It's another TBK Mini from BastardKB. The difference from my last build is (hopefully) better build quality and hot swap.

How I built it

1. Printing the case

I started by printing the case on my Ender 3 printer with eSUN PLA+ Cold White filament. I sliced it using Ultimaker Cura with the following settings:

  • Standard Quality - 0.2mm
  • Build Plate Adhesion: Brim
  • Supports: Tree supports

2. Ordering custom PCBs

On the last build I was't really happy with how messy the micro controller ended up. And hand-wiring the controller was a bit of a pain.

3. Wiring the flexible PCBs

I wired the columns together by running one wire through all of the row holes. I found that this worked out best after some trial and error. I would have been really happy with one extra row hole on every key-switch section since it got pretty tight with the diodes that I used.

Soldering Flexible PCBs

Then I soldered the hot swap connectors and tried out the fit in the case.

Trying out the fit Closer look at the flexible PCBs

I wired the thumb clusters on one row and to columns that matches the original firmware (and my last build).

Thumb cluster wiring

4. Wiring the Elite-C-holder

I wired the Elite-C-holder according to the excellent Prepare the Elite-C build guide.

I then wired everything just like my previous build. I could have mirrored the halves like the original TBK minis but I still had to change the diode direction on that firmware so I chose to stick with the firmware that I had already made. Image how I wired before

Update 2022-02-20

After the build I decided that I would wire it as the stock TBK mini. The both sides are now mirrored.This means that as long as I change the diode direction to #define DIODE_DIRECTION COL2ROW I can use the stock firmware.

Wired as the stock TBK mini

All done.

All done with wiring

5. Setting up the firmware

Since last time I have started to use my own userspace in the qmk firmware repository. It makes it really easy for me to use the same layout on all of my keyboards.

I used the following command when building my own miryoku inspired layout.

MAKEFLAGS="COL2ROW=yes" util/ bastardkb/tbkmini:cfarvidson

To make this possible I added the following in users/cfarvidson/

COL2ROW ?= no
ifeq ($(strip $(COL2ROW)), yes)
	COL2ROW = yes

and this to users/cfarvidson/config.h

#if defined(COL2ROW)

6. All done

I added white NP keycaps from keycapsss.

The final look of the keyboard The final look of the keyboard

I'm really happy with the end result.