Distance between switch cut outs

Learning and discussion
1

MX switches.

My math for the distances between switch cut outs isn’t quite matching what I’m finding in plate dxfs.

1U to 1U: 5.05mm(19.05-14). No problem.

1.25U to 1U: My math says 7.43125.

((19.05*1.25)-14)/2) + (5.05/2)
(23.8125-14)/2 + 2.525
9.8125/2 + 2.525
7.43125

1.5U with same math=9.8125mm

But I’m seeing distances slightly off. For example, the ergodox full hand dxf has 9.8425mm between the left 2 columns.

What is normal for this?

Also why do some mx holes have notches but others are just squares? Is that what I’m misunderstanding?

2

Top/bottom notches or side notches? The latter would, I believe, be for switch-top opening.

3

your math is correct, but not all plates use 14 x 14 switch holes. I’m wondering if that tiny different on the ergodox plate is coming from someone using a plate generator. I’ve noticed slight differences when I’ve used plate generators versus just manually doing the plate