Seeking lighter gauge springs

[richard]

Hi

I've been told there is a standard gauge of wire that is used for all concertina springs. 

 

I would like to find someone who can make me a few lighter gauge springs to try out on a concertina. I know there are ways to light the pressure by moving the spring, and bending the wire over and over again, but I would like to see if I can find a lighter spring that would work. I know it could be to light, but I am curious.

 

Is there someone out there who could make a few of these for me?

 

Thanks,

 

Richard

[JD Rogers]

Concertina connection https://www.concertinaconnection.com/ uses a thin gauge steel wire as opposed to the thicker phosphor bronze and explains why here: http://www.concertinaconnection.com/about_ airflow.htm

 

I made a spring winding board and could post photos if you want to try it yourself. Similar to Alex Holden's https://www.holdenconcertinas.com/?p=831 but a bit simpler for doing small quantities I needed. I am very happy with the result.

 

As for the physics, my take is that you have 2 parameters you can control:
1. spring constant k, determined by the material (type, temper, thickness), coil diameter,  and the number or turns.
2. Where on the displacement curve you start (more pre-compression when the button is up is farther out on the curve)

 

Those two parameters affect the force and the force profile as you push the button, but the effect of profile is pretty small for the range of motion of a button. The main thing is the initial force. Since you can lighten that by setting the spring angle when it is unhooked, you may not notice much difference with different materials. But it will be interesting if you do!

 

Wakker has some good info on his site, including the tip that while it might seem like a good idea to have light springs, this does not necessarily mean faster, because the spring does not snap the pad closed as quickly, and you may end up with insufficient pressure to provide solid seal and prevent leaking air throughout.

 

I feel like others have some good info as well, perhaps Tedrow? Others, please chime in if I am forgetting any!

JDR