what are the most ergonomically important features of an ergonomic keyboard?

[taako]

I am designing a keyboard which i want to meet the following criteria:

1) Fully split design
2) Column Staggered
3) Concavity
4) Thumb button arcs or clusters
5) Fully programmable keys
6) Fully programmable RGB LEDs

and i have started the CAD designs of the keyboard base but  with a standard - non flexible - PCB i can only have the concavity going along one axis.

Currently i have design it to have concavity in the column direction, in order to have each column at different heights and angles i would have to sacrifice this so that the PCBs were columns set at different heights and angles.

Ergonomically is it more important to have concavity for rows of keys or columns? My gut instinct says column concavity is more important because i do more stretching to reach keys up and down than left and right. The only real problem comes in with my pinky that would prefer being raised up a little relative to my other fingers.

The kinesis advantage (and similar) have both row and column concavity but it uses a flexible PCB, and i'm wondering how important the row concavity is.

I understand that i could forego this problem if i just skipped the PCB and handwired the keyswitches but then i'd be giving up ease of assembly and lighting as the addressable RGB SMD LEDs would be very difficult to handwire.

So in order of importance what are the most important features of an ergonomic keyboard? Is row concavity more important than column concavity? What else is more or less important?

Here are some pictures of my current CAD design after a very first 3D print. Right npw it is missing many keys but i printed this just to get an idea of the angles the keyswitches should be at. This design is compatible with one PCB per row and is column staggered as well as column concave.

[algernon]

I'd add tenting / tilting support to that list, along with good physical key placement, especially on the pinky columns. As an example, on the Keyboardio Model 01, the pinky columns are positioned lower than on - say - the ErgoDox. This makes the keys (think P, for example) easier to reach with shorter pinky fingers. Also, when designing keys for the thumbs, keep in mind how many one can reach and press without also pressing another, or having to lift one's hand. The ErgoDox thumb cluster is awful in this regard, there are 3 usable keys there only, and 3 others almost wasted.

[taako]

I'd add tenting / tilting support to that list, along with good physical key placement, especially on the pinky columns. As an example, on the Keyboardio Model 01, the pinky columns are positioned lower than on - say - the ErgoDox. This makes the keys (think P, for example) easier to reach with shorter pinky fingers. Also, when designing keys for the thumbs, keep in mind how many one can reach and press without also pressing another, or having to lift one's hand. The ErgoDox thumb cluster is awful in this regard, there are 3 usable keys there only, and 3 others almost wasted.

Yes tenting and tilting is necessary. I understand the physical placement is important and thats why coumn staggering is necessary. But is angled rows or height staggering more important to go along with column staggering?

[tp4tissue]

Tenting (55 degrees and up)

along with

Programmable..


Everything else you've mentioned,  not that important.

[crystalhand]

The first 3 are how I would rank the importance for an ergonomic keyboard.  Some things to note in my opinion
An extra bottom layer is needed for me and the dactyl does this very well.  I like having those keys at the bottom.  The manuform does not do this nearly as well the 6x6 version is huge and the 5x6 gives up to many keys. 

While people focus on the thumb cluster a lot I don't think its as vital as others.  The manuform has maybe 1-2 more usable keys for the thumb positions.  I find that i rarely use more than 3 or so thumb buttons regularly.  I think the iris handles this part well.

5 and 6 are nonimportant.  The build is going to have to be handwired anyway so qmk will be used more than likely.  As for leds... I never understood those.

[taako]

The first 3 are how I would rank the importance for an ergonomic keyboard.  Some things to note in my opinion
An extra bottom layer is needed for me and the dactyl does this very well.  I like having those keys at the bottom.  The manuform does not do this nearly as well the 6x6 version is huge and the 5x6 gives up to many keys. 

While people focus on the thumb cluster a lot I don't think its as vital as others.  The manuform has maybe 1-2 more usable keys for the thumb positions.  I find that i rarely use more than 3 or so thumb buttons regularly.  I think the iris handles this part well.

5 and 6 are nonimportant.  The build is going to have to be handwired anyway so qmk will be used more than likely.  As for leds... I never understood those.

In terms of concavity do you think its more important to have depth stagger across fingers (pinky keys higher than middle finger) or angled rows (home row flat, bottom and top row angle inwards towards home row)?

Im working on a design and i can make it easily with almost all my features except i cant have both. So which type of concavity is more important? Regardless of which type on concavity i choose i can still have the columnar staggering so keep that in mind.

[Koren]

In terms of concavity do you think its more important to have depth stagger across fingers (pinky keys higher than middle finger) or angled rows (home row flat, bottom and top row angle inwards towards home row)?

I'd say it depends how you want to type...

Depth stagger is probably good on all keyboards.

Angled rows, on the other hand, are interesting if you type on upper/lower rows at an angle with respect to the keyboard "normal". It may be interesting if your palm is resting and not moving at all (Kinesis style). I'm less convinced for a normal keyboard where your palm "floats" above the keyboard.