20 Button Double Reed Anglo Finger Pressure Vs. Single Reed Finger Pre

[darticus]

Is this normal? Is more finger pressure needed to push buttons down because of air needed? Maybe double springs are used because of two reeds??? I guess a construction person is needed to answer this. Thanks Ron

[Patrick McMahon]

I would take your guide from the world of accordions.

I have a couple of melodeons with four voices per button. They have stops that you can operate, to choose one, two, three or four reeds at a time. The button pressure is not excessive.

On many accordions, you have four voices as standard on the bass side, and much bigger reeds. Again, the button pressure is not much different to a concertina, if at all.

 

So, I think the answer is no.

[Stephen Chambers]

It may have more to do with who made those concertinas than anything else.

[BW77]

I would take your guide from the world of accordions.

I have a couple of melodeons with four voices per button. They have stops that you can operate, to choose one, two, three or four reeds at a time. The button pressure is not excessive.

On many accordions, you have four voices as standard on the bass side, and much bigger reeds. Again, the button pressure is not much different to a concertina, if at all.

 

So, I think the answer is no.

There are several factors involved here. The valves are larger on accordions and the spring resistance to seal them higher. The button resistance differs likewise,while it usually is about 50 gram on concertinas my Hohner one row got 150+ grams. Since its buttons however have a diameter of 10 mm and the concertina buttons 5 mm the *button pressure* will be less all the same with the accordion.

[Patrick McMahon]

There is the matter of pressure too.

Because the ends of a concertina are so much smaller in area, you can generate more pressure for the same squeeze or pull force in a concertina than an accordion. So the springs are working against higher pressures.

 

I've never measured the button force in a piano accordion, but on the bass side, the buttons are the same size as concertina buttons, but the pressure on the finger feels much the same, for a button operating several very big reeds.

[BW77]

There is the matter of pressure too.

1) Because the ends of a concertina are so much smaller in area, you can generate more pressure for the same squeeze or pull force in a concertina than an accordion. So the springs are working against higher pressures.

 

2) I've never measured the button force in a piano accordion, but on the bass side, the buttons are the same size as concertina buttons, but the pressure on the finger feels much the same, for a button operating several very big reeds.

Concerning 1) above

There are different "pressures" of importance here.

a) The general air pressure within the box when you squeeze and the related necessary spring force being the force needed to seal the valves...( the "springs are working against" this pressure)

The pressure (gradient) created over the the reed slot when playing decides the tone amplitude and I doubt there is much difference here between ( good quality) accordion reeds and concertina reeds

 

Due to the difference regarding end areas between accordions and concertinas, just like you say, the pressure (a) at the same executed arm force will (mostly) be greater with the concertina. But in practise you probably adjust the arm force to the wished tone amplitude - related to pressure ( and thus use less arm force when playing concertina. The "spring force" you feel when playing is independent of the air pressures, it only reflects the button resistance which in turn is only depending on the spring strength and the leverage

 

Concerning 2)

I got just one Hohner piano accordion to check, but both the white and black keys have a resistance of ca 50 grams at the free end (while at the base it may become more than 200) . The base buttons are NOT the same size as concertina buttons, they are 7,5 mm wide. Their resistance is a bit uneven but 100-120 grams. The important fact here is that if comparing a 5 mm button and a 7 mm one with the same spring force ( =button resistance) the (touch-) *pressure* with the 7 mm one will be only half of the pressure with the 5 mm one. Thus you gain a great deal of comfort with just a little bit wider buttons OR you may use stronger springs with wider buttons when using the same button-pressure and get faster action and more efficient sealing of valves.

 

So - WHY has tradition become what it IS, that :

Concertina buttons are smaller/leaner than accordion buttons while there are good arguments for wider buttons?

Springed forces are greater with accordions than concertinas?

These are still un-answered questions......

[darticus]

Thanks all. I have a double reed that uses double the finger pressure than used on a single reed box. I guess there is no connection to button pre sure and reed amount. Ron

[BW77]

Thanks all. I have a double reed that uses double the finger pressure than used on a single reed box. I guess there is no connection to button pre sure and reed amount. Ron

 

Thanks all. I have a double reed that uses double the finger pressure than used on a single reed box. I guess there is no connection to button pre sure and reed amount. Ron

Excuse me Ron, but to make this understandable you have to specify :

1) your "single reed" and your "double reed"? - are they really exactly the same instruments apart from having single reeds and double reeds? What make and models are they?

2) what exactly do you mean by "finger pressure"?? Do you mean *button resistance* = the weighed force needed to press down the button = the spring force x the leverage OR do you mean the *touch pressure on the finger* = the button resistance/button end area ? How have you measured your "finger pressure" ?

3) what do you mean by "reed amount"? The pressure gradient over the reed slot ? - you may call that *playing pressure* ( in German it is called "Spieldruck" - is not related to the button resistance/button pressure

4) when speaking about spring/button resistance and conditions related to valve sealing and general air pressure within the boxes you have to consider of course the leverages both for the valve and the button vs the spring. Constructions may differ a lot. You may attach the spring directly at the valve ( with no leverage) and the button being at the other end of the lever, OR the spring may be acting at the same side of a pivot as the valve, OR at the other side of a pivot, same side as the button.

[darticus]

I have a newer Stagi single reed and soft light button pressure. Very easy to press buttons. I have a Bastari new but 30 years old double reed but to push buttons it has about a 3 times force to press buttons down. Good practice to play first than go to the light concertina and float. Would the reeds cause this or just spring pressure.

Please don't say I have to spend big bucks to get it right by buying a name brand. Thanks Ron

Edited December 27, 2016 by darticus

[BW77]

I have a newer Stagi single reed and soft light button pressure. Very easy to press buttons. I have a Bastari new but 30 years old double reed but to push buttons it has about a 3 times force to press buttons down. Good practice to play first than go to the light concertina and float. Would the reeds cause this or just spring pressure.

Please don't say I have to spend big bucks to get it right by buying a name brand. Thanks Ron

Can't you measure the force needed to push down the buttons in both cases? Would be interesting to know. You just need a 100 gram weight and a rod. The construction is probably quite different so everything else seems hard to comment unless you take them apart but it sounds as if the spring force is very much different but WHY that is so will likely remain an unanswered question unless you get some constructor to tell. Maybe you can replace one or two springs with weaker ones to see what happens? If the valves don't leak maybe the spring force can be a bit reduced all over...

[darticus]

Thanks for all the help and suggestions. I will keep an eye out for something to measure pressure and post. It does feel nice and solid but forces these old hands to be a little slower on the buttons. All 20 buttons feel the same so I think its correct from the factory. A weight heavy enough to push the button down and than weigh the weight would do it. I'll work on it. Maybe this New old Stock concertina is filled with money and its holding the buttons from moving with light pressure. LOL!Thanks Ron