Key staggering

[blastoid]

With the popularity of the planck, ergodox, and other ortholinear boards, I began to notice something a bit odd about normal, staggered layouts. The bottom row of every keyboard I've looked at is offset from the home row by 50%, but the top row is only offset by 25% to the left. Surely there's some history to this design. Does anyone have any more info?

[Findecanor]

On the mechanical typewriters each key was connected to an arm that extended in front of the keyboard. The staggering of the keys makes the arms equally spaced. No arm interferes with another.

You can see the key-arms in this picture:

[blastoid]

Perfect!

Although, it still seems like they could have gone with shifting the bottom row 25% to the right instead of 50% and still achieved the same result, while maintaining a uniform stagger.

[Data]

Perfect!

Although, it still seems like they could have gone with shifting the bottom row 25% to the right instead of 50% and still achieved the same result, while maintaining a uniform stagger.

Yeah, looks like it's staggered 1-4-2-3 instead of 1-2-3-4, which would have produced a more uniform stagger @ 25% per row.  I'm sure there's some logic behind it.

[jacobolus]

Specifically, there’s 140+ years of history https://geekhack.org/index.php?topic=61586





As for the logic, the bottom two rows and the top two rows attached to hammers which struck the paper (at the bottom of the cylinder) from opposite directions, which is why within each of those groups the rows are offset from each other by half a key width.

Later typewriters (a few decades after the original Sholes & Glidden a.k.a. Remington #1 design) had all the keys’ hammers hitting the paper at the front of the cylinder, and all coming from the same direction, so the 1/2, 1/4, 1/2 stagger didn’t make quite as much sense, but by that point, the layout was already established.