Broken Reed On A Wheatstone Miniature English

[adrian brown]

My wife managed to break a reed on her miniature English the other evening; first it tried to turn into an anglo and had a semitone between push and pull, then it snapped completely across the reed, one third from the tip. This is something that I've never managed to do on any of my anglos, so I'd like to ask if this is something to be expected on such a loud, small instrument with such tiny reeds? (It was an E6 and the instrument is from 1927) Can we expect more to go the same way, assuming she uses the same sort of welly in the future?

 

Adrian

[Don Taylor]

Just a thought, but given a much smaller end area, maybe half as much as on a regular sized concertina, then it seems to me that air pressure over the reeds will be much higher for the same amount human muscle force.

 

There have been a number of comments about how loud miniature concertinas can be, is this the reason?

 

Also, maybe this also explains why modern hybrid ECs in 7+" boxes are soft. Ceemonster might want to try one of smaller Morse hybrids?

[Geoff Wooff]

You can expect a plethora of broken reeds and I suggest cutting your losses now and selling me that miniature . I'll take it off your hands at a discount rate... call it danger money if you will. Cracking reeds and splitting ear drums... think of the public liability... have your audience insurance ?

 

Only joking. I guess those small reeds and the greatly increased pressure available could be a dangerous combination. On the rare occasions I have come across broken Steel reeds they have always been instruments played by women..... perhaps they put more feeling into their music , squeeze those sounds ?!

 

My thoughts on power output of concertinas have moved towards crossectional area and number of reeds on a reed pan. Orientation might have something to do with it too. The damping effect of radially arranged reeds as opposed to the in-line with the grain reed possitions of an up to 30 key Anglo may well be responsible for large differeces in volume between instruments.

 

Modern hybrid instruments are quite different in construction and I am not sure if it is possible to equate size for size with Traditional instruments.

 

An experiment I am carrying out just now is to judge the difference (in volume) between two almost identical concertinas, one with wooden and one with metal ends. I am getting a feeling that it is a perceived volume change due to tonal character.

Edited September 12, 2015 by Geoff Wooff

[adrian brown]

You can expect a plethora of broken reeds and I suggest cutting your losses now and selling me that miniature . I'll take it off your hands at a discount rate... call it danger money if you will. Cracking reeds and splitting ear drums... think of the public liability... have your audience insurance ?

 

 

Mits off Wooff - you ain't 'avin it!

 

I made a replacement tongue for it yesterday, cutting it out of an old flexible ruler that had the same thickness. Took ages to file it to shape, but it seems to work quite well for a first attempt. The sound is close enough to its mate, but lacks a bit of pitch stability, going very slightly flat at high pressure. I guess I haven't got the profile quite right - I left it a bit thicker than the original, .11mm at the tip as opposed to .07mm, or maybe the stainless ruler just isn't a match for spring steel? Perhaps I'll just leave it like this as a sort of "built in" db meter

Just wondering if we should carry a set of replacement reeds with us...

 

Adrian

[Dana Johnson]

 

You can expect a plethora of broken reeds and I suggest cutting your losses now and selling me that miniature . I'll take it off your hands at a discount rate... call it danger money if you will. Cracking reeds and splitting ear drums... think of the public liability... have your audience insurance ?

 

Mits off Wooff - you ain't 'avin it!

 

I made a replacement tongue for it yesterday, cutting it out of an old flexible ruler that had the same thickness. Took ages to file it to shape, but it seems to work quite well for a first attempt. The sound is close enough to its mate, but lacks a bit of pitch stability, going very slightly flat at high pressure. I guess I haven't got the profile quite right - I left it a bit thicker than the original, .11mm at the tip as opposed to .07mm, or maybe the stainless ruler just isn't a match for spring steel? Perhaps I'll just leave it like this as a sort of "built in" db meter

Just wondering if we should carry a set of replacement reeds with us...

 

Adrian

Stainless comes in many varieties, but even the spring stainless steels I've seen area little less stiff than the original 1095 steel, so the profiles would be different slightly. The flattening of pitch can be due to too much flexibility in the profile ( thinner in the central area ) but my experience with high reeds doesn't suggest this is likely. If your reed is not properly centered, it will flatten in pitch under pressure, and I find this across the board. When centering by eye with a backlight, if your eye is the slightest bit off directly vertical from the reed, it will make the reed appear closer go one side or the other. Being closer to one side at the tip causes more trouble than at the base, but it is hard to get the tip right if the base is not reasonably centered. Some people use a strip of thin paper laid over the window and press the reed down onto it so the paper creates a shim on either side. Most normal paper strong enough not to be torn by the reed is too thick for a decent reed. I use a non stereo low power 10X microscope to center my reeds, but any magnification is useful.

While it is easier to produce high pressure in small concertinas, the reeds respond in the same range. While people might go overboard, I'd expect them to temper their efforts to the results and not expect significantly higher pressures at the reeds. Miniatures I've seen would be under tremendous pressure if people used the same force since the pressure varies with the area.

A lot of things can cause breakage, like poor profiling, deep file scratches, corrosion, even being played really loud for a long time. I wouldn't expect the rest of the reeds to go just because one did.

Dana

Edited September 14, 2015 by Dana Johnson

[conzertino]

Adrian, I would advise you to make the new tongue from an old concertina-reed ( I could send you one )!

 

Geoff, I have two miniature Aeolas for sale: http://www.concertinas.de/concertinas ;-)

Edited September 14, 2015 by conzertino

[d.elliott]

I have a 12 k Wheatstone miniature, no fractured reeds (yet) but some are a bit like tuned baking foil.

 

Technically, reeds crack through metal fatigue. Think of the frequency of the high pitch reeds compared with the mid range treble. 1 Hz is a cycle or vibration per second

 

A4= 440Hz is mid treble clef,

A5 = 880Hz

A6= 1760Hz

A7= 3520 HZ or 8 times as many vibrations per second of sounding

 

The reed is thinner, therefore any stress raising scratch or file mark bites proportionately deeper into the reed's cross section; this creates a greater weakness but also a more significant 'stress raiser' in the metal surface.

 

For any particular metalographic structure, metal fatigue is not necessarily a result of degree of force (magnitude of resultant stress), but of the number & speed of cyclical flexing coupled with the presence of stress raisers (shape and surface texture).

 

Hence, in engineering, the need to blend shaft or spindle diameter transitions with radii (no sharp corners or undercuts). On high frequency shafts you polish the transitions to avoid scratches and marks that will form stress concentrations (raisers). Applying this to reeds, I long since stopped using conventional files, but prefer to polish/ shape reed tongues using very fine grit diamond files. You get more control in metal making tuning easier and actually extend the reed life.

 

Back to the miniature, the thin metal of the reeds, with file marks vibrating 8 times more per second of play, the miniature's reeds are a lot more susceptible to micro cracking and metal fatigue failure.

 

The only reliable solution is to do what a certain person did and place it in the hands of the Horniman where it will disappear from human ken, never see the light of day and suffer zero cycles per second for ever more. Much to the loss of the general population at large

 

Dave

[adrian brown]

Thanks for your help, and the reassurances that our mini is not going to suddenly shed all it's reeds like a deciduous forest:-)

 

I have some reed blanks on the way, courtesy of the amazing generosity of this community, and I'll try to do a better job with my next attempt. For the moment, my first attempt is holding up fine, though a little on the unstable side.

 

Thanks again,

 

Adrian

[Geoff Wooff]

Geoff, I have two miniature Aeolas for sale: http://www.concertinas.de/concertinas ;-)

So you have Robert.... Perhaps for my christmas present then ?... I'm frying other fish this month but I will keep your baby Aeolas in mind!

Edited September 21, 2015 by Geoff Wooff