concertina

NOTES.md

 1
 2All of this is modelled on Amy's "Irish Concertina Company Vintage" Irish concertina.
 3
 4The Kailh MX Switches I got are 14mm across:
 5exactly the right size to provide the same spacing.
 6I think of the buttons as going three across, in 5 rows.
 7
 8Positioning the buttons
 9-------------------
10
11Here's how I think of it:
12
13We start with five rows of three buttons each.
14Within a row, buttons are spaced 14mm apart 
15(x = [0, 14, 28]).
16Then we stack the rows at 15.5mm apart
17(y = [0, 15.5, 31.0, 46.5, 62.0]).
18Then, we stagger the rows by skewing the X offset
19(x = [0, -3, -7, -14, -22]).
20The ending positions of the first button in each row are:
21[[0, 0], [-3, 15.5], [-7, 31.0], [-14, 46.5], [-22, 62.0]]
22Finally, the entire thing is rotated by 20°.
23