I've been planning on doing a custom 60% build for a while now, and today I ordered the first of my parts. I plan to assemble everything myself, including a hand-wired matrix and from-scratch firmware.
The first decision I made was what physical layout I wanted to work with. I decided on a Poker II physical layout for a couple of reasons. It was the easiest 60% board to find a plate for, as the Poker is one of the most common 60% MX boards, and it allowed me to use 100% standard size keycaps. I wouldn't have to dig around for a 1.75x shift or a function cap. I considered having two 1u keys in the space usually dedicated to the backspace, so that I could have esc and `~ on the top layer, but decided against it in favour of ease of sourcing parts.
The next step I took was to determine a layout for the top layer and the function layer. The biggest decisions I faced in the top layer was determining whether I wanted `~ or esc in my top left corner, and which bottom row keys to sacrifice for fn keys. Because I find myself spending a lot of time in linux on the command line, I decided I wanted ready access to `~. As I have never used the apps button or the right super key in my life, I changed those keys to fn lock and fn respectively. On my function layer, I duplicated all the functionality I lost on the top layer going from a TKL board to a 60% board. Esc and f1-f12 fill the first 13 slots in the top row (backspace is left accessible). WASD is replaced with arrow keys. TYU/GHJ are replaced with the 6-key cluster, and OP[{ is replaced with Print Screen/Scroll Lock/Pause. I do frequently use print screen and pause, scroll lock is kept for the sake of completeness -- otherwise I'd keep a blank space between the two keys to keep the spacing the same relative to each other.
http://www.keyboard-layout-editor.com/#/layouts/30f7d2f9ef2a1f81a14cd943a95efd23http://www.keyboard-layout-editor.com/#/layouts/9a639f9115c36b014a15cffce344eeb3I envision the fn and fn lock keys to act in a similar way as caps lock and shift do on the alphas. Pressing fn lock will lock the board into the function layer, or what I call "web mode" This leaves me with access to all the keys I use on a regular basis when browsing the internet, in conjunction with a mouse -- arrow keys, home, end, pgup, pgdn, f5, f11, backspace and tab. When in this mode, holding fn will return me to the standard layer, and allow me to type a short phrase (i.e. web address) by hunting and pecking with my other hand. For typing more in depth (i.e. forum post), I can exit the function lock, and use both hands. If in the top layer I need to access one of the function layer keys, I can use the fn key as normal.
The only thing this layout sacrifices is a second function layer for a number pad. My next project will likely be a custom MX numberpad, unless I buy a separate numberpad in the meantime. The lack of a number pad is something I have never had an issue with on TKL boards, I don't expect to miss it any more in a 60% layout. Having a separate number pad would allow me to place the pad to the left of the keyboard, and allows me to have the pad in a non-staggered layout and with 2x keys, which is what I am used to.
Next step was to decide on a controller and other parts. I have costar stabs from when I harvested parts from my RK-9000, and I have enough switches to do MX blues or MX greens. If I decide I want to do clears, I'll need to order another 50 switches, so I'm going to go ahead with greens for now. I need a controller that can accommodate at least 61 intersections, which means I need 16 available pins for an 8x8 or a 7x9 matrix. I decided on an Arduino Pro Micro because I've heard a lot of good things about working with them. If I run into trouble, my dad has written keyboard firmware for an old alps board on one of these, so I have a resource if I need it. To get better than 2KRO, I need diodes, and I've ordered 500 1N4148. This is enough for my keyboard and planned numpad, as well as some spares and components for other projects.
I'm still looking around for a plate and a case. At this point, I'm more interested in a plate, as if worst comes to worst, I can mount the whole assembly on a block of wood. However, I'll need a plate to begin the wiring. If anyone has any suggestions for sourcing a Poker II plate or similar layout with support for plate mounted stabs and switch cutouts, I'm all ears. I'm hoping to get a plate in a neutral colour, as I don't know yet for certain what caps will end up on this board (at this point, probably toxic, maybe Ivan's PBT blanks).
Parts list:
Switches (have, MX Blue/Green)
Stabilizers (have, costar)
Diodes (ordered)
Controller (ordered)
Plate (Need)
Case (Need)
Caps (ordered compatible)
Feel free to discuss, offer criticism/feedback, etc. This is my first custom build, so I expect some stumbling blocks, hopefully I don't break too much of anything.