Pneumatics

[John Sylte]

I’ve had this idea in my head for years… instead of buttons connecting to pads with levers, use pneumatics. I’ve done all sorts of googling but never really found anything like I was imagining until I saw this;

 

https://www.facebook.com/share/v/1EYaJxkXmD/?mibextid=WC7FNe

 

https://fb.watch/w3MFWS_RRe/?

 

hope those links work? 

 

i was thinking you could use pneumatics along with a fully chromatic reedpan, map the buttons to whatever notes you want, and rotate the reed pan to change keys. With an air piston like this, you could connect to a pivoting pad/spring with tube and effectively cover each hole with the same sensitivity as your finger tips. Am I dreaming? I’m not an engineer. But I’ve had this evolving in my head over the last 12-15 years, but no time or resources to do anything with it. 

[RAc]

I would expect those pistons to be audible when they release, also, I do not think they would respond quickly enough for fast playing. Finally, the overall weight with a fully equipped concertina may be rather taxing.

 

But hey, experimenting with stuff like that keeps you off the bad side of the road, so why not give it a try?

Edited November 25 by RAc

[Richard Mellish]

A conventional mechanism with a lever and spring moves the button back out when you release it. As seen in the videos, this pneumatic thingy appears to have a slight leak, such that the piston drifts slowly downwards by gravity. Even without that, I suspect that the button would not come all the way back out when you release it. In principle it might be possible to use air pressure from the bellows to re-charge the pneumatic cylinders, but that's getting very complicated. And I agree with RAc that the weight could be a problem.

 

All that said, some arrangement allowing you to change the mapping of buttons to notes might have some merit, if it can be done without too many drawbacks.

[John Sylte]

So I am not sure exactly how these work, but I know a fair amount about conventional liquid hydraulics. I’ve ran and fixed farm equipment my whole life. Instead of an individual piston for each button, which would be way heavier than levers, perhaps a master cylinder could be enabled, managing pressure in all lines equally? Or maybe just plastics with a closed air system/small airbags could be used instead? Maybe pneumatics is overkill. 
 

A rotatable reedpan would obviously have to be radial, like an English, with an in/out for each button, and slightly bigger to accommodate keys G/D - D/A. Might need to be in 3D somehow, like double helix shaped. Mad scientist at work here. 🤓

[Richard Mellish]

I have had another thought about rotating the reed pan to change keys, which applies regardless of what mechanism you use between the buttons and the pads. If you're changing Anglo layouts between G-D and D-A, the notes for the D rows (right and left ends) remain the same, but you will still need a lot of additional notes, because the overall range on each end is increased by a fifth. If you want to go between a standard C-G and a standard G-D it's much worse, because the G rows on a C-G are an octave higher than the G rows on a G-D.

 

It could be somewhat more practicable with English layout, where you might change by one tone per step.

 

Or you can play a Hayden, where the fingering remains the same across many keys without any internal re-arrangements.

[Chris Ghent]

Love the ideas, but note the cost of precision.  

[Clive Thorne]

Full marks for the free thinking. It's how great ideas happen.

 

However, in this case, I suspect you're trying to solve a problem that doesn't really exist. The traditional lever mechanism is very light, responsive, and relatively cheap. Development of the existing mechanisms might be more fruitful, e.g 3D printed pads (already done by some I believe), PTFE for the bushing plates, or lever pivots, etc.

 

I did see something somewhere where someone has used a bowden cable to operate a couple of his reeds, so a button on one side would operate a reed on the opposite edge of the instrument,. Doesn't seem to have caught on though.

 

I've been down many rabbit holes myself, thinking I have a great idea for something, only to realise that it really isn't required, or is impractical/too expensive.

 

Edited November 27 by Clive Thorne