How does shorter button travel affect playablility?

[richard]

Hello

 

I am wondering if having a shorter button travel distance helps or hinders playing on an Anglo and/or English concertina. Part of me thinks having all the buttons set to travel half the distance that is normally set would increase the potential speed of playing.

 

Does anyone have experience with this sort of arrangement?

 

Thanks,

 

Richard

[Ransom]

Surely you don't want it too long, but I wouldn't simply suppose that shorter is better (or even faster). Keep in mind that on the other side of the button is a lever attached to the pad, and shorter button travel distance means a shorter motion for the button-end of the lever. Depending where the fulcrum is, that means that either your pad won't open up as far, or you'll have to push harder on the button-- either one of which could slow down your playing.

[david_boveri]

i rarely press buttons down all the way: you only need to press them down far enough to get the reed to sound. however, i would never want anyone restricting how far i could press them down for the reason ransom stated above. also, you must consider that for different sorts of sounds/chords, you need to press harder or softer depending on what you need.

[Chris Ghent]

You can certainly play faster with less travel. In order to shorten button travel I have put pivot points closer to the button to keep the same amount of pad lift.

 

I'm told a common ratio of button travel in older instruments was 1/4"/1/8", ie. button height at rest 1/4", button height at bottom of travel 1/8". The resulting 1/8" travel is 3.1mm, I am using 2.75mm. If there is a downside it is that on the longer levers (and therefore all of them) spring tension needs to be increased to keep the pressure at the pad the same. Also if you have any effects depending on half pushed buttons they will need to be a finer judgement than before.

 

If you have an instrument which has more than 1/8th" travel it may be the pads have sunk or the felt washer under the button has compacted or thinner pads have been fitted at some point. Of course it might just have been made that way.

 

I'd be interested David to hear you set out the parameters of the different sounds you get by pushing harder or softer..?

 

Chris

[Rod]

You can certainly play faster with less travel. In order to shorten button travel I have put pivot points closer to the button to keep the same amount of pad lift.

 

I'm told a common ratio of button travel in older instruments was 1/4"/1/8", ie. button height at rest 1/4", button height at bottom of travel 1/8". The resulting 1/8" travel is 3.1mm, I am using 2.75mm. If there is a downside it is that on the longer levers (and therefore all of them) spring tension needs to be increased to keep the pressure at the pad the same. Also if you have any effects depending on half pushed buttons they will need to be a finer judgement than before.

 

If you have an instrument which has more than 1/8th" travel it may be the pads have sunk or the felt washer under the button has compacted or thinner pads have been fitted at some point. Of course it might just have been made that way.

 

I'd be interested David to hear you set out the parameters of the different sounds you get by pushing harder or softer..?

 

Chris

 

 

Any button travel in excess of that required to efficiently and effectively open the spring-loaded pads serves no practical purpose, imposes unecessary tension on the springs, and for other obvious reasons is surely best avoided ?

[Mikefule]

A few times I have tried playing a friend's Anglos, both of which are the smae make, and both of which have a longer button travel than any of my boxes. I hated it. It felt less intuitive, and very clumsy - mechanical rather than musical. However, he swears by them, and he's a far better and more experienced musician than I. So within certain common sense practical limits, I guess it's personal preference.

[Dirge]

The point is surely that the pad lifts the moment the key is touched because the spring takes most of the slop out automatically. It's just the cross bushing in the key that can provide a variable. You don't get your note at the bottom of travel; air starts moving the moment you tickle the button. So travel to make a noise is virtually nil. The idea of shortening travel to speed up response is therefore a red herring; travel is already almost absent.

 

Shortening travel to speed up return to 'fingers ready to pounce on the next note' position might be affected I suppose, but I don't know the keys go all the way down when I'm playing fast anyway; I rather doubt they do.

[Geoffrey Crabb]

<P>Content removed as not deemed relevant.</P>

Edited June 4, 2012 by Geoffrey Crabb

[richard]

Hello

 

My theoretical thinking in this line of thought is that:

 

Once the button has been depressed to the point that the pad has lifted, any further movement down until the button stops is wasted movement and wasted time.

 

I am not in search of some secret or short cut path towards mastery, skill, or playing faster than good music demands. I think the goal should be to be able to hit the buttons and have enough control and "touch" to kiss the button and not have it travel more than is needed. Although I asked my teacher and he (as I recall) implied that he presses the buttons down till they stop.

 

Richard

[Dirge]

No, the note doesn't get full volume unless the pad is decently off the hole, so you'd end up with a muted instrument. You could change all the leverages to shorten button throw but it would make the keys harder to press and less controllable. As David B mentioned earlier, you want to be able to vary pad lift and speed of opening on subtle stuff.

[Frank Edgley]

A lot of good thoughts out there. My opinions:

(1)-shorter travel from unpressed to fully pressed can be achieved by changing the position of the fulcrum so that the ratio of fulcrum to button and fulcrum to pad is altered. (This is not a home repair - merely a design consideration.) If the fulcrum is moved closer to the button, the pad will lift off the vent hole further with less button travel. This, of course, will increase the pressure required to press the button, but will reduce the button travel. Mechanical advantage has been changed, so there will be less spring pressure on the pad and leaks may occur, unless spring pressure is increased.

(2)-lower or shorten the fulcrum pivot point. (Again a design consideration, not a home remedy) This will reduce the button travel, and also reduce the elevation of the pad when the button is fully pressed. This will affect the volume of the instrument and may alter the pitch and reed response, depending on the extent of lowering, and the air requirements of the reeds in your concertina.

 

The ideal design is a compromise, or finding the ideal balance between height, pivot point and travel, etc. Over the years, if the pads have been replaced, they may not have been replaced with pads of the original thickness, or the pads may have compressed, so the original button travel may have been compromised.

Edited June 4, 2012 by Frank Edgley

[Robin Harrison]

...........I have an anglo that was used by a member of the Albion Country Dance Band that he had had Colin Dipper put on very long buttons because he was also a guitar player and didn't want to damage his nails. I had Colin put on much shorter ones.

It does surprise me how much difference the length seems to make..........I have another anglo with what I think are longer buttons and I really don't enjoy playing it. I try to tell myself it shouldn't make any difference becuase your finger pads don't actually touch the end-plates.

Robin

[RatFace]

I tried reduce the button travel distance long ago (on my english) by making a set of cardboard (I think) washers to go over the beg - next to the existing felt washers.

 

However, whilst it worked, it had two side effects (that I remember - it was a very long time ago!). One was a reduced volume and a more muted tone, which I didn't mind at all. However, it also introduced tuning problems - getting the same effect (though to a less extent) as the technique for bending notes on a concertina/accordion - only partially depressing the button and increasing the pressure. Concertinas have tuning problems enough (i.e. their pitch depends a lot on the volume, to the extent that they always sound out of tune to me), so this experiment was pretty short lived.

 

I'm sure it would work if the levers were changed to get the same pad lift as normal - but then the springs would have to be stiffer to compensate (in order to get the same air tightness when the pads are down).

[d.elliott]

A lot of good thoughts out there. My opinions:

(1)-shorter travel from unpressed to fully pressed can be achieved by changing the position of the fulcrum so that the ratio of fulcrum to button and fulcrum to pad is altered. (This is not a home repair - merely a design consideration.) If the fulcrum is moved closer to the button, the pad will lift off the vent hole further with less button travel. This, of course, will increase the pressure required to press the button, but will reduce the button travel. Mechanical advantage has been changed, so there will be less spring pressure on the pad and leaks may occur, unless spring pressure is increased.

(2)-lower or shorten the fulcrum pivot point. (Again a design consideration, not a home remedy) This will reduce the button travel, and also reduce the elevation of the pad when the button is fully pressed. This will affect the volume of the instrument and may alter the pitch and reed response, depending on the extent of lowering, and the air requirements of the reeds in your concertina.

 

The ideal design is a compromise, or finding the ideal balance between height, pivot point and travel, etc. Over the years, if the pads have been replaced, they may not have been replaced with pads of the original thickness, or the pads may have compressed, so the original button travel may have been compromised.

 

I think your points about design and what can be done at home are extremely valid. For repairers & owners then the data given by Chris is significant and very important. My summary of the key travel question is as follows.

 

You need around 3mm of key standing proud of the finger board when the key is fully depressed, otherwise the player can loose where they are in play. I have seen & played instruments where the keys are 'lost' when depressed, there is no sense of place. This is adjusted by the damper stack height under the body of the key.

 

The travel distance, coupled with an even key height is the other variable. The design of the instrument is such that usually such that 1/8th of travel gives enough air to yield responsiveness and volume. this is set whenever the pads are changed. Too little lift on the pad and the note does not sound properly; too much lift, is too much key travel and the instrument becomes hard work. I set at 3mm, knowing that pad compression will give a little bit more over the first few years.

 

Pad thickness simply sets a starting point for travel adjustment. but on some instruments a thick pad can cause the pads leather bead to tap on the underside of the finger board, very annoying, and in my earlier days it took me a long time to work out what was happening when I first met the problem. Concertina Spares do sell an optional 'thin' pad.

 

In my view, stick to Chris's data, and look at Dirge's comments. In play bellows control and fingering technique (player skill) should do the rest. Unless, of course, I am playing when the buttons change place randomly and keep ducking.

 

 

Dave