Closing bellows

[Elizabeth]

I think i read somewhere, here? That a lmm accordion has bellows that are easier to close than a lmmh because there are less read blocks? Comments…? Thank you.

 

[Dingo40]

An interesting question: model A is longer but model B is wider, so to speak.
A uses less air, but does B have more capacious bellows?
A pushes fewer reeds, but does having more openings (reeds) reduce back pressure?
What's the score when using couplings sounding an identical number of reeds in both accordions?
So many interacting variables!
In a practical sense, I can't say I've noticed.
Maybe I'm just insensitive!

 

[debra]

I think i read somewhere, here? That a lmm accordion has bellows that are easier to close than a lmmh because there are less read blocks? Comments…? Thank you.

That is mostly nonsense if you refer to closing while playing or closing using the air button or also closing without pressing any key/button.
Of course the amount of air inside, and thus the dimensions of the accordion, that plays a role in how much air is involved in opening and closing the bellows. And when using the air button the size of the hole this button opens determines how easy it is to close the bellows.
There are accordions on which the bellows close faster than they open while you play, but that is determined by the sum of all the tiny air leaks in the pallets. When you close the accordion the air pressure pushes the valves open, hopefully not enough for any note to sound, but enough to make the bellows close faster than when you open the bellows (when the valves are sucked closed by the reverse air pressure). That is mostly a factor of the age of the accordion. An LMMH accordion has pallets that close 4 holes and LMM only 3 holes so by that account an LMMH accordion should be losing more air when you close the bellows than an LMM accordion.

 

[Elizabeth]

An interesting question: model A is longer but model B is wider, so to speak.
A uses less air, but does B have more capacious bellows?
A pushes fewer reeds, but does having more openings (reeds) reduce back pressure?
What's the score when using couplings sounding an identical number of reeds in both accordions?
So many interacting variables!
In a practical sense, I can't say I've noticed.
Maybe I'm just insensitive!

Your answer just washes over my head, somewhat! But i do get that: so many interacting variables! And one variable maybe important to one player but not so much to another.

 

[Scuromondo]

I think i read somewhere, here? That a lmm accordion has bellows that are easier to close than a lmmh because there are less read blocks? Comments…? Thank you.

My interpretation of your question is that you are asking whether a 3-reed accordion requires less effort to operate the bellows (opening, as well as closing) is that correct? When the “master” switch is selected to engage all reed sets (3 on LMM, 4 on LMMH), if all other things are the equal, the 4-reed accordion will obviously require more air than the 3-reed accordion. But I still don’t think one can categorically say the 3-reed accordion will necessarily feel “easier” to open/close.

 

[Ventura]

it requires energy to move the air

so, number ONE in importance is how efficient is the use of that air/energy
by the accordion itself (ie: overall quality of design. fit, and reeds)

next, how often do you have to change direction of the bellows while playing ?
so number TWO in importance if the design and construction of the bellows...

the same model of accordion with a crappy little bellows could have a couple of
extra folds added which would improve it

or the same model (if dimension allows) could have deep bellows corners, which
would improve it a great deal

therefore, there is no overall simple physical answer... each individual accordion
(and it's design) must be evaluated for whether it will be an easy player,
or a real bear to squeeze (preferably before you buy it)

 

[Elizabeth]

That is mostly nonsense if you refer to closing while playing or closing using the air button or also closing without pressing any key/button.
Of course the amount of air inside, and thus the dimensions of the accordion, that plays a role in how much air is involved in opening and closing the bellows. And when using the air button the size of the hole this button opens determines how easy it is to close the bellows.
There are accordions on which the bellows close faster than they open while you play, but that is determined by the sum of all the tiny air leaks in the pallets. When you close the accordion the air pressure pushes the valves open, hopefully not enough for any note to sound, but enough to make the bellows close faster than when you open the bellows (when the valves are sucked closed by the reverse air pressure). That is mostly a factor of the age of the accordion. An LMMH accordion has pallets that close 4 holes and LMM only 3 holes so by that account an LMMH accordion should be losing more air when you close the bellows than an LMM accordion.

Lightweight and light to the touch seems begging for an LMM configuration without cassotto. LMM versus LMMM or LMMH means (besides less weight) smaller pallets which require less force to keep closed when you push hard, so the accordion can be light to the touch.

The above quote from an earlier post is what got me curious about 3 versus 4 reed blocks. It was smaller pallets which require less force according to theabove comment, not reed blocks.
Thank you for your response to my comment.

 

[debra]

What we have not yet considered here is that the effort for closing the bellows while playing depends a lot on the weight of the bass side you are moving. Normally the bass side goes down a bit as you open the bellows so you have to lift it back up as you close the bellows and the heavier the bass side the more effort it takes for that. Whether the treble side is 3 or 4 (or 5) voice has no influence on the effort needed to move the bass side.

 

[Elizabeth]

it requires energy to move the air

so, number ONE in importance is how efficient is the use of that air/energy
by the accordion itself (ie: overall quality of design. fit, and reeds)

next, how often do you have to change direction of the bellows while playing ?
so number TWO in importance if the design and construction of the bellows...

the same model of accordion with a crappy little bellows could have a couple of
extra folds added which would improve it

or the same model (if dimension allows) could have deep bellows corners, which
would improve it a great deal

therefore, there is no overall simple physical answer... each individual accordion
(and it's design) must be evaluated for whether it will be an easy player,
or a real bear to squeeze (preferably before you buy it)

Thank you for your response to my post. Lots of things to think about.
I reread the quote that i had seen, and it stated the size of the pallets made the accordion apoear to be easier and lighter to operate. Not number of reed blocks.

 

[Ventura]

well well well, less or more pallet leakage on the close...

i cannot see how this translates to affecting the touch much

touch is a byproduct of the tension of the key return spring,
the pivot point(s), and the finish (smoothness and fit) of the
friction and guide parts of the action mechanicals
(and on some old accordions, whether the leather faces are sticky)

a nice light touch keyboard easily overcomes the initial resistance
of the spring and the actual weight of the lever because the whole
of the action is well finished and fitted by a good craftsman and the
designer of the action

how would the size of the pallet make a difference ? certainly the
surface tension from air-pressure is minimal and unless the leather is sticky,
what other resistance can the pallet offer too opening force needed?

 

[debra]

well well well, less or more pallet leakage on the close...

i cannot see how this translates to affecting the touch much

touch is a byproduct of the tension of the key return spring,
the pivot point(s), and the finish (smoothness and fit) of the
friction and guide parts of the action mechanicals
(and on some old accordions, whether the leather faces are sticky)

a nice light touch keyboard easily overcomes the initial resistance
of the spring and the actual weight of the lever because the whole
of the action is well finished and fitted by a good craftsman and the
designer of the action

how would the size of the pallet make a difference ? certainly the
surface tension from air-pressure is minimal and unless the leather is sticky,
what other resistance can the pallet offer too opening force needed?

To keep a large pallet (covering 4 or even 5 holes) closed under pressure (on push) it needs to be kept closed with more force than for a small pallet (covering 2 o 3 holes). Whether there is cassotto to divide the "work" over 2 pallets doesn't matter. It's the number of voices, and thus the number of holes the pallet(s) need to keep closed that determines how strong the return springs need to be. So a 2 voice accordion keyboard can be much lighter to the touch (and still keep the holes closed) than a 5 voice accordion.

On old accordions the pallets may start leaking, quite evenly, so while they all leak a bit of air it's just not enough to get a note to sound (without pressing a key). I have seen a performance from an accordion group with mostly old players using old accordions. It was quite funny to watch: they would play 3 bars on pull followed by 1 bar on push, then 3 bars pull and 1 bar push again, etc. These accordions were leaking so much (through the pallets) that they used (actually, wasted) 3 times more air on push than on pull.

 

[Ventura]

"....they used (actually, wasted) 3 times more air on push than on pull."

now that is a huffin and a puffin

i hadn't thought about the number of holes/reedblocks allowing the designer
to choose a lighter spring tension. and i guess on some high quality 3 reed strollers
that i have known like the Sonola strollers and the Tonaveri Ranger, i always thought
their actions were so comfortable

but my 5 reed Excelsior 960 is also easy on the fingers.. i guess they had some
darn good people at CEMEX back in the day finishing the action setup

 

[Hilobox]

An interesting question: model A is longer but model B is wider, so to speak.
A uses less air, but does B have more capacious bellows?
A pushes fewer reeds, but does having more openings (reeds) reduce back pressure?
What's the score when using couplings sounding an identical number of reeds in both accordions?
So many interacting variables!
In a practical sense, I can't say I've noticed.
Maybe I'm just insensitive!

I find this thread interesting because I have three instruments of similar size and weight. The Bravo III is subjectively easiest, ie less force to pull and push the bellows, but requiring perceptively more travel. The bellows measure approx. 8”x15” or 120 sq in “piston” area. The V30 requires the least movement to sound, and is quite sensitive to minor changes, 90 sq in. The Marchesa also feels more pressure- rather than travel-sensitive, 119 sq in. It’s sound volume seems the most powerful. The Bravo is LMM, the other two LM, so there is that variable. I thought of doing measurements: movement speed, movement distance, only one reed, and constant sound level using a decibel meter. But all of that sounds too much like real work. Now if had such data across several hundred accordions, I’d know how to proceed, ha. Or go mad. Or more mad. Aloha.

 

[Hilobox]

I find this thread interesting because I have three instruments of similar size and weight. The Bravo III is subjectively easiest, ie less force to pull and push the bellows, but requiring perceptively more travel. The bellows measure approx. 8”x15” or 120 sq in “piston” area. The V30 requires the least movement to sound, and is quite sensitive to minor changes, 90 sq in. The Marchesa also feels more pressure- rather than travel-sensitive, 119 sq in. It’s sound volume seems the most powerful. The Bravo is LMM, the other two LM, so there is that variable. I thought of doing measurements: movement speed, movement distance, only one reed, and constant sound level using a decibel meter. But all of that sounds too much like real work. Now if had such data across several hundred accordions, I’d know how to proceed, ha. Or go mad. Or more mad. Aloha.

Sorry for my ridiculous bunch of words. I just find these instruments so very amazing as machines.

 

[debra]

Sorry for my ridiculous bunch of words. I just find these instruments so very amazing as machines.

Accordions are amazing machines. It has a similar number of parts as a church organ, but all squeezed together in a small box. One of the important lessons I learned during the ACA repair courses was to take lots of pictures during the disassembly process so as to know how everything goes back together.

 

[Hilobox]

Paul, when I was young, I played the organ, and a few times a pipe organ. Right now I am trying to play a simple Bach organ prelude on the accordion, substituting bass for pedal and chords for lower manual bass clef. Sadly I am a very poor accordionist. In the eighties a systems programmer on an IBM mainframe said an organ was far more genius than a computer, therefore by your extension so is the accordion.

 

[debra]

Paul, when I was young, I played the organ, and a few times a pipe organ. Right now I am trying to play a simple Bach organ prelude on the accordion, substituting bass for pedal and chords for lower manual bass clef. Sadly I am a very poor accordionist. In the eighties a systems programmer on an IBM mainframe said an organ was far more genius than a computer, therefore by your extension so is the accordion.

That systems programmer was definitely right. In the eighties I did a lot of (systems and application) programming myself (and that went on into the nineties, becoming a bit less in the new century as I got others to do it for me). I also messed around with the insides of computers and find it sad that now they have become more of a black box. Working on an accordion is actually often more challenging than computers were in the previous century. (But I can imagine that many people might disagree because some of the detective work I had to do to find a solution for some tricky issues with some computers might seem more of a challenge than the mysteries found inside accordions.)

 

[Hilobox]

That systems programmer was definitely right. In the eighties I did a lot of (systems and application) programming myself (and that went on into the nineties, becoming a bit less in the new century as I got others to do it for me). I also messed around with the insides of computers and find it sad that now they have become more of a black box. Working on an accordion is actually often more challenging than computers were in the previous century. (But I can imagine that many people might disagree because some of the detective work I had to do to find a solution for some tricky issues with some computers might seem more of a challenge than the mysteries found inside accordions.)

Oh dear. My own professional life. Doppelgänger.

 

[Hilobox]

Paul et al, do you see the similarity between the Stradella mechanical system and an SQL query with joins, etc.? Are you equally impressed with this engineering?

 

[debra]

Paul et al, do you see the similarity between the Stradella mechanical system and an SQL query with joins, etc.? Are you equally impressed with this engineering?

We're going way off topic here...
But no, I don't see a similarity. The Stradella mechanism has a very clear and in essence simple structure and does one thing very well. It may look complex to the innocent bystander but once you learn what is there it's very structured and simple (but laborious) to disassemble and to put back together. I taught databases, including SQL queries, and that requires strict logical thinking, to continuously come up with queries for questions that always change, or to see what different queries mean in plain English. (And that's just querying, not yet considering transactions with locking...)
The accordion is basically not really "complex". It is relatively easy to understand until you try to find out why certain things behave abnormally (like finding a resonance somewhere, or a slightly misaligned reed tongue, or why one note may sound weaker than the others...). It's just the sheer number of small components cramped together in a small box that creates the "illusion" of complexity in the accordion (and that makes people afraid to touch anything inside).