Paintbrush Keyboard Thoughts

recently i bought a paintbrush keyboard kit from keebd. it’s a 8 key mechanical keyboard, designed to be used by people with 4 fingers. i built it because:

• i wanted to learn how to solder (specifically, i wanted a friend to teach me how to solder)
• i wanted to learn how to assemble custom mechanical keyboards
• i wanted to fiddle with QMK firmware
• i wanted a switch tester for choc v1 switches
• but i also wanted to check for accidental key activation, so i wanted to put them in an actual keyboard and see what was required to get them to activate

i think its a cool little macropad, and fiddling with ARTSEY as a 1-handed input method is fun.

keebd’s build guide is very sparse though. what i recommend is looking through splitkb’s build guide for its aurora-series products to understand how to build a keyboard for the relevant parts. see also everything in its resources section to learn about soldering and what tools you need and so on. ill post what was used below.

specifically, as someone who built a wired version, i only soldered the hot swap sockets, pro micro-compatible microcontroller unit (with sockets), oled (with sockets), populated the switches with the ones i bought, and flashed the firmware with the one that keebd offered. it also came with an acrylic base plate with standoffs, which isn’t in that guide, but it’s relatively straightforward. just make sure you have precision screwdriver bits for torx screws, because thats what the base plate screws use.

keebd offers a few microcontrollers, but i used the helios. its the main one the site offers with QMK compatability and QMK firmware. it also has a lot of flash storage (16mb), so if you wanted to reuse it as a MCU for a DIY stenography keyboard you can flash javelin-steno on it relatively easily (i imagine).

so i learned how to solder (with a friend teaching me, thank you jess!) and i learned how to assemble a keyboard, kinda, though it has no diodes like more complex boards so its not the best indication. it gives me a way to fiddle with firmware, and i can see how different choc v1 switches feel, and see how much force is needed to activate them.

basically, i bought 2 types of switches: reds (50gf linear), and ambient twilights (35gf silent linear). ambients are much nicer to type on and they really are silent. i ran my 4 fingers across a row of each to see how they felt. the reds felt a bit too heavy for me relative to the twilights. based on this im hoping a glove80 with its cherry blossom switches will be good for me. (confusingly, the cherry blossoms are not a cherry mx switch! theyre a choc v1 switch!)

this cost me about 100aud. $20 for the keyboard kit, $14 for 10 of the red switches, $16 for 10 of the twilight switches, $25 for the controller, $9 for 10 keycaps, and $10 for other misc parts like the controller/display hotswap sockets.

is it worth it? mostly of. i get an impression of how it feels to type on these switches with multiple fingers, but i didnt get an impression of how it felt to type with my thumb. probably the better strategy, if you can afford it, is: buy a kit for a keyboard that you will actually want to assemble, even if you only get 1 set of switches. that way, when you want to assemble that keyboard, you dont need to spend extra on a different kit.

for example, at some point ill want to buy a kit for the sofle 2.1 choc, so i should have bought that kit and assembled one half. then i could have placed those switches in strategic parts of the keyboard: 4 on the home row position, 4 on the corners of each column, and 2 on the thumb cluster. it would give me a better idea of what typing would be like as it includes the thumb.

right now, with the paintbrush, i can only test what typing is like with my fingers and not my thumb. and if i want to use the sofle now, i still need to buy the kit for that, and i obviously wouldnt have to if i already did that instead of getting the paintbrush.

anyway i also bought a handful of things to solder with, and my friend brought some too. i already had a soldering iron (specifically a pinecil) and a precision screwdriver with replaceable bits. heres what i bought that got used:

• solder - 0.7mm diameter, 60/40 (which means its leaded), 2% flux. i got 15 grams but we didnt need that much
• sidecutters
• a solder sucker/desoldering pump
• desoldering braid
• polyimide tape - when people talk about kapton tape for heat resistance, thats a specific brand of polyimide tape. we also used it for electrical isolation on the bottom of the oled

here’s what my friend brought that got used:

• a cork board to solder on
• brass wool, to clean the soldering iron
• flux, in a syringe
• helping hands, the stand thing with alligator clips
• a fan, to push solder fumes out the window

thats my experience with building the paintbrush. one thing i want to do is set up an additional ARTSEY layer to input some key combos used by the android screenreader TalkBack so that i can navigate my phone using only 8 keys.