Gday, I'm designing my first keyboard, to be CNC'd from plywood. I'm currently designing in Fusion 360, trying to lay out the keys correctly.

From what I understand, the keys have standard sizes (multiples of a "unit"), so, for example, a 60% keyboard is 15 units wide. However, there is a different number of keys on each row. Therefore, the gaps between keys on each row must be different. Otherwise, each row would have a different width.

Is my understanding correct?

It doesn't seem right though, since it would mean that the gaps in the bottom row are more than twice as large as the gaps as the top row, since there are fewer gaps. Any help would be much appreciated!