Reed shoe dimensions

[nickwitha_k]

Hello folks: 

 

I'm new here but am pretty much constantly tinkering with something (adult ADHD). Recently, I've had a few ideas that I would like to try, such as metal composite materials (HTPLA + metal as well as other possible composites) as well as sand casting reed shoes. I want to make some to test both if they work at all and, if so, if there is any impact on the tone between the different materials (I'm an open-source nerd, so, all of my data will be posted somewhere).

 

However, I haven't really been able to find a good source for the dimensions of the traditional reed shoes. I've searched the forums and the Internet at large with minimal success. 

 

Could someone point me in the right direction for a source of dimensions for the different shoe sizes (and their assigned notes)? I'd like to create some CAD models to use and share.

 

Additionally, what is the current thinking on reed blank material? Spring steel? Brass sheet? What initial thickness of the stock (I'm aware from my reading that the profiling is...weird)?

 

Thanks very much!

[Chris Ghent]

A couple of thoughts. 
 

There are no standard reed frame dimensions for vintage concertinas; modern concertinas are more consistent within brands but not guaranteed to be identical.  If you want to experiment you might be best to select a particular concertina and copy it.  
 

When testing materials for frames and tongues note that reeds do not actually make any noise, they meter air.  Tone differences between say, for example, steel and brass reflect the different stiffnesses of the material, leading to more or less air being allowed through, hence volume differences, and slower or faster reed tip speeds leading to more higher partials in the sound, or less with the brass. 
 

The weight of the frame and the rigidity could affect the union with the wood creating a stronger or weaker fundamental.  
 

Sandcasting of frames is not wonderfully accurate like machining and diecutting.  I have seen modern silicon moulded phosphor bronze frames but they were slow to use because of unpredictability at the micron level.  
 

Profiling obeys the theory or relativity so not weird.  Weaken the root it slows down and flattens, lighten the tip it speeds up.  

[gtotani]

Have you visited Harmonikas website?

HARMONIKAS - Home

 

[d.elliott]

gtotani, The drawings you post are for a variant of accordion reed. I would not use them as a standard for a true concertina reed. 

[David Lay]

15 minutes ago, d.elliott said:

gtotani, The drawings you post are for a variant of accordion reed. I would not use them as a standard for a true concertina reed. 

Are these used in Suttner and Garvey concertinas or do they have another source?

[gtotani]

20 hours ago, David Lay said:

Are these used in Suttner and Garvey concertinas or do they have another source?

I am also curious to know. 

 

Also, what are the difference between "variant of accordion reed" and "true concertina reed"? 

Surely, they should sound different. What makes the difference?

I wonder how "true concertina reeds" could have been mass produced in the past. (or were they NOT mass produced?) 

[Tiposx]

The riveted “Dix Concertina” reeds ( in the top drawing) are used in the Irish Concertina Company “Vintage” model of 2023.

[David Lay]

2 hours ago, Tiposx said:

The riveted “Dix Concertina” reeds ( in the top drawing) are used in the Irish Concertina Company “Vintage” model of 2023.

Garvey and Suttner both use screw clamped reeds.  I had an Edgley with riveted reeds.

[Takayuki YAGI]

In my view, it is the relieved vent slot that is important, whether screwed or riveted. I would like to know the cross-sectional shape of the slots in the DIX series. Do they slightly widen towards the bottom side?

[Tiposx]

Hi Takayuki YAGI

I am interested in how vent slots are shaped/ relieved. I noticed that Irish Concertina Company specified tapered slots in their top model in 2023 when I bought my "Vintage" model (I think they called it the Eiru Gold model).

They did not seem to make any claims at that time  about how such slots affected the tone or response of the reed. I still don't know the answer.

Also I don't know if the taper would have been at the sides of the slot, as you suggest, or at the tip.

Some of my Lachenal and Wheatstone reeds seem to have a very small 45 degree (approx) taper at the bottom of the slot, both at the sides and the tip.

I wonder where the magic happens?

Regards

Tiposx

 

[Kevin Knippa]

The clamped reeds that ICC uses in the Gold Eiru models have tapered vents. The tapering is on the sides of the vent, and maybe at the tip. Their website describes them as, "Inside Reed Angled for less restrictive Air Flow." The clamped reeds in the Silver Eiru do not have the tapered venting. 

 

This video shows the difference between the reeds in Gold and the Silver. I think the reeds are modified DIX Concertina Original reeds.  I suspect Harmonikas makes the vented reed shoes for ICC, but they are not a product that Harmonikas offers to the public. I think ICC is now using a branded clamp bar, but it is just a cosmetic difference..

 -

So now the question is, does a clamp over a rivet really make a difference in sound? Some historical concertinas used riveted reeds.

Or, does the reed tapering in width along its length make a difference in sound from the rectangular reed?

I have an ICC vintage. The reeds do not sound like conventional accordion reeds. Is it the brass shoe that makes it different?

[Takayuki YAGI]

7 hours ago, Tiposx said:

They did not seem to make any claims at that time  about how such slots affected the tone or response of the reed. I still don't know the answer.

A quote from Alex Holden's website:

 

"One of the defining characteristics of traditional concertina reed shoes is that the underside of the vent is relieved (i.e. the bottom of the slot is slightly wider than the top). My current understanding is that this allows the reed to work properly even at very low bellows pressures, i.e. it enables you to play quietly if you want to. It also has an effect on the tone. "

 

Please refer this page https://www.holdenconcertinas.com/reed-prototypes-part-1-frame-and-clamp/ .

[Takayuki YAGI]

6 hours ago, Kevin Knippa said:

I suspect Harmonikas makes the vented reed shoes for ICC, but they are not a product that Harmonikas offers to the public.

Interesting to know that. Thank you. So how about Frank's "new model"??

[gtotani]

12 hours ago, Tiposx said:

 

They did not seem to make any claims at that time  about how such slots affected the tone or response of the reed.

 

The Irish Concertina Company now claims that

 

To explain there is angling done on the inside of the shoe to allow for better air flow as the reed tongue travels through the Brass shoe / Plate. This produces optimum sound performance.

 

This angling allows for better airflow as there is less friction on the tongue as it passes through the Brass Plate/shoe and this in turn gives the reed a more mellow sound.

 

The Irish Concertina Company | The Eirú Professional

[Tiposx]

That quote rings a bell, so to speak. I didn't find it convincing enough to pay the extra though.

I had a look at the Alex Holden website. I am always inspired by the quality of his work. His explanation of the benefit from opening out the reed frames does sound a little equivocal though. I might just be misinterpreting his words. Perhaps he might comment on that.

What I am getting at is wether or not it would be worth putting a taper into the slot of accordion reed plates, or Dix Concertina plates. Would the taper work if it was only at the tip end? What would the advantage actually be?

It is the sort of thing that can be experimented with , I may have to try it on some accordion reeds.

 

[alex_holden]

I don't agree with the statement about vent relief reducing the friction between the tongue and the frame. There shouldn't be any friction with either style of reed frame. If there is any contact between the two it either doesn't sound at all, or makes an annoying buzz.

 

I do agree that a reed assembly with vent relief is less restrictive to the air flow, but I suspect that has more to do with reducing how much of the cycle the reed is mostly blocking the vent. With a relieved vent the reed only interrupts the air flow very briefly whereas with an accordion-style unrelieved vent there is a more gradual opening up of the vent as the reed passes through it. Surprisingly this improved air flow doesn't seem to translate to greater air consumption from relieved reed assemblies.

 

I think a relieved vent is more responsive and has more dynamic range, and the tone is a bit different in a way that myself and some (many?) players prefer. I don't like to try to describe the difference in words because it's so subjective.

 

I don't know if there is any significant difference in the performance of a screwed clamp vs a rivet. One benefit of screws is you can easily take it apart if you ever need to adjust the fit or replace the tongue.

 

If you are buying unrelieved reed assemblies there may be some benefit to taking them apart and manually filing in some relief (anecdotally I have heard that there is at least one maker doing this). That would be much easier to do if the tongue is screwed down rather than riveted. Only relieving the tip might help a bit; I'm not sure how much difference it would make. It's important when relieving the vent to not accidentally widen the top face, increasing the gap between the tongue and the frame.

[Tiposx]

Hi Alex

Very impressive work, as always.

I had imagined it would be a 45 degree taper that stopped some way from the top surface of the plate. Your filed surface looks shallower than that in angle, and goes closer to the top surface than I thought it would.

Cheers

Tiposx

[alex_holden]

14 minutes ago, Tiposx said:

Hi Alex

Very impressive work, as always.

I had imagined it would be a 45 degree taper that stopped some way from the top surface of the plate. Your filed surface looks shallower than that in angle, and goes closer to the top surface than I thought it would.

Cheers

Tiposx

Yes, mine are 15° from vertical and stop as close as I dare (a small fraction of a mm) to the top face. Other makers may vary.