Updated: Feb 25
Let's compare ThumbsUp! v3 and Georgi. They have a lot in common, the general layout is the same, both just naked PCBs, and actually ThumbsUp! would not exist if not for Georgi.
For the purpose of this article it could be any other similar board instead of Georgi.
Here is my hand lying on the table in a neutral relaxed position. (Yes, I know that's not ideal hand position, but that's how I mostly sit.)
My thumb and index fingers are from the keys.
To press them I either have to rotate my hand to more pronate position, which is uncomfortable.
(Yes, if my forearms were not laying on the table that would be less of a problem, but that would not eliminate hand pronation, so the hand position would remain practically the same. I shall return to that question later when I demo ThumbsUp! usage with a laptop in my laps.)
Or to stretch out the thumb and the index finger, which puts them to outside of the normal movement range:
A usual solution is to tent the keyboard:
Alternatively the keyboard is tilted away (aka negative tilt):
Or it can be both tented and tilted. It is quite close to Dactyl, Dactyl-Manuform, and a bit like Kinesis, but just flat.
With the raised thumb and the index finger keys the keyboard puts those keys at the right level. All the fingers are now in their neutral position, from which they move just a bit to press the keys.
What about other fingers, don't they need to be put on their own levels? Well, yes, that'd be nice. From other hand they are naturally on the same flat panel, and the column stagger compensates the difference in their lengths just fine.
One may ask: why not just add a tenting/tilting platform if tenting and tilting seem to resolve the hand pronation issue? That's for another post.