I pseudo-built my first (and only) custom keyboard in this thread (
https://geekhack.org/index.php?topic=44831). I liked the design a lot but I could never get a case made correctly and didn't make the plate large enough to use as the top piece of case so it never came together as an actual keyboard. After reading the thread about "fixing" the ergo-dox, it inspired me to revive and update my design, re-make the plate, and finally get the keyboard I want.
I thought I would go through my design iterations and see what feedback people have. I like a ~10 deg angle on the rows and a minimum of thumb keys. All of the designed have more keys in the upper, outer corners and the lower, inside corners because that minimizes the horizontal space needed with the 10 deg rotation angle. I tried a Kinesis and it killed my thumbs (tendonitis) so I also don't need a big thumb cluster like the ergodox.
Here was my initial design (complete w/ dsa retro cap coloring). I like a lot about it but I didn't like the lack of an arrow cluster and the placement of the quote key and the slash key were a real pain. They're largely an artifact of my desire for a symmetric layout.
Design #1:
After reading the tread on the ergo-dox thumb cluster, I realized that I could greatly reduce thumb travel by using an arc'ed set of keys for the space bar and Fn keys (my primary thumb keys) and add one more key (backspace?) without much worry. I also added some vertical offset to the finger columns as well. My thumbs rest perfectly on the space bars and it's only a small move to hit the key to either side. This design still has no arrow cluster and the quote and slash keys are still in bad locations.
Design #2:
The easiest way to fix the quote and slash keys was to go back to the qwerty layout. I figured out that I can make the enter key 1u wide and get very close to a standard keyboard layout on the right hand with this change without making it much larger. That allowed me to add in an arrow cluster on the right hand and another nav cluster (probably not that important to me) on the left hand. Increasing the arc of the thumb keys also helped with thumb placement. I don't think hitting a 1u enter key is a problem and I may use one of the extra thumb keys as a enter key as well.
Design #3:
After studying that design, I realized that I could get back to a symmetric design if I use 1u keys for the left side tab and ctrl. I'm not sure why I like the idea of a symmetric design so much and it doesn't really add that much functionality (I don't actually need those keys) so I'm not sure about this one.
Design #4:
So I'm leaning heavily towards design #3 with some small thoughts about #4 right now. I'd love to hear any ideas, thoughts, and criticisms that people have of these.