Chromatic button accordion measurements?

[jonathan5]

Hello all,

I am currently working on a project to (mostly) 3D print a chromatic button accordion. I would like to base it off of the design of a bayan, but I am a piano accordion player who doesn't have access to any CBA for measurements.

I was able to use the dimensions of a bayan button and some diagrams online to estimate the dimensions of the keyboard, and from that I have been able to build a functional prototype. I know I got some of the dimensions wrong: the action feels far too deep, and the step height between the rows was more or less a guess. I plan to create a second prototype with a more precise mechanism and more accurate keyboard dimensions, and to hopefully share it online so that anybody with access to a 3D printer and some reeds can enjoy it.

This brings me back to my own unfamiliarity with bayans. I would like to ask if anybody here who is more familiar with them could tell me what the dimensions of the keyboard should be? I am putting below all of the rough measurements I used for the prototype. I am especially looking for input on button press depth and row step height, but please tell me if any of my other measurements seem off.

13.7mm button diameter
19.5mm distance between buttons on the same rows
17.25mm distance between the rows
5.5mm step height between the rows
8mm button press depth

Thank you very much,
Jonathan

 

[donn]

For a Cavagnolo, ca. '60s. (It's not a "bayan", but it's a C-griff chromatic button accordion, which may be what you mean.)

Button 14.1 mm
Spacing in row 18.7 mm
Spacing between rows 15.7 mm
Step height 3.25 mm
Press depth 6.6 mm

Not really standardized dimensions - others will have larger buttons, closer buttons, etc. The buttons on this accordion are flat, which I think is not the most common.

 

[jonathan5]

Thank you! It may not be a bayan, but I doubt that the dimensions are significantly different.

It is encouraging to see that I was not too far off with my measurements. This is very helpful, especially the values for press depth and the step height. Thanks again!