Concertina action constructions

Subject: Concertina action constructions
From: Guran
Date: 21 Mar 14 - 03:50 AM

"Riveted action vs pivot action" ...British style concertinas - anglos, duets, englishes - historically have come with two common types of mechanism popularly called "rivet action" represented by the most common Wheatstone models and "pivot action" represented by the most common Lachenal models.Both terms indicating the method connecting the lever with the post.
The term "pivot action" is not very adequate since ALL are in real *pivot* mechanisms so I suggest "hook/saddle" types for the latter in stead despite there are in reality dozens of technical variants.

The main discussion mostly deals with comparisons between the major groups : 1) riveted Wheatstone-like and 2) hooked Lachenal-like but it may be added that late Wheatstones had 3) a saddle construction with a loose connection stabilized by an overfolded post

Anyway...When quality of different concertinas is discussed and compared this subject often comes up and arguments may be very determined regarding what model is the "best". My impression is that "riveted action" is promoted as a sign of "higher quality" but sometimes with vague arguments.

Therefore it would be interesting to hear opinions among players on this subject

Göran Rahm

Subject: RE: Concertina action constructions
From: Bert
Date: 21 Mar 14 - 05:55 AM

I thought that concertina actions were just push and pull :-)

One time I bought a Chemnitzer that I started to restore. I don't know it it is still around or whether it got lost in a move. When I get settled again I'll see if it survived in all my junk.

Subject: RE: Concertina action constructions
From: GUEST,Oscar Wilde
Date: 21 Mar 14 - 06:49 AM

Sounds riveting.

Subject: RE: Concertina action constructions
From: GUEST,Black belt caterpillar wrestler
Date: 21 Mar 14 - 07:12 AM

In the riveted system the lever is held to the side of the post by a rivet passed through both. This is inherently asymmetric and over the course of a few million button depressions will cause the hole in the lever to wear to the point where the lever becomes liable to break. This is more prevalent where the spring pressure is greater so the first to go is the air button lever, and yes I have experience of this.
The hook under system can still be asymmetric depending on the alignment of the components with the pad position but does not suffer wear in the same way.
It seems to me that the hook system does not ensure such a quick return of the pad to its sealing position when the button is released, though this may just be my subjective impression. The whole lever can move away from the fulcrum when depressed and so take longer to return to its rest position. You have to be playing really fast pieces to detect anything but I think that I have done on occasion.
Perfection would be a frictionless pivot in a split lever that passed both sides of the post.

Interested to hear other opinions.

Subject: RE: Concertina action constructions
From: GUEST,disgusted tunbridge wells
Date: 21 Mar 14 - 07:21 AM

Bert, they are both Unisonic and Bisonic, the Unisonic has two familes the Duet and the English.
Duets always have bass left, treble right, I know nothing about the English

Subject: RE: Concertina action constructions
From: GUEST,chris
Date: 21 Mar 14 - 11:29 AM

Have a look at Rock Chidley's action
Chris

Subject: RE: Concertina action constructions
From: Guran
Date: 21 Mar 14 - 12:38 PM

Caterpillar wrestler,

"riveted...wear to the point where the lever becomes liable to break"

G: I haven't come across that before..only wear enough to make the connection loose and at the other end getting stuck from debris if not been used enough

"...the hook system does not ensure such a quick return of the pad to its sealing position when the button is released"

G:I have experimented with this and if the spring tension is accurate ( meaning a button touch pressure usually of 50-75 gram ) and no defects are present this should not happen. IF however you for some reason wish to use an extremely low button resistance ( with the risk loosing tightness of pads) the riveted system is safer

" The whole lever can move away from the fulcrum when depressed and so take longer to return to its rest position. You have to be playing really fast pieces to detect anything.."

G: I was intrigued by the similar report many years ago but then with a claim that it caused rattle and clicking ( said being inherent with Lachenals) so I set up a test trying to observe the phenomenon. Some escape by the lever did happen, but only at a speed of 2000+ beats per minute - varying a little between different levers. No clicking or escape could be detected at normal/fast playing conditions. ( No-one plays as fast as 2000 beats/min...)

"Perfection would be a frictionless pivot in a split lever that passed both sides of the post".

G: I haven't seen a split lever. Split posts have been tried by several makers (see below) and mechanically this does look better than the asymmetric variant. Ideally I would use that also ( IF using an axis/rivet at all) but adding a ball/bead at each side between the lever and post. The question is if such a mechanically perfected solution would have any significant effect on musical performance...

Chris,

Yes, Rock Chidley used a forked post on instruments with his own label and so did some other old time makers too. Some modern makers/repairers use it also both on new instruments and old ones. I know that some people have had the action exchanged to this type. In theory it does look neat but again - does it really mean any real improvement in practise? And what in such case?

Subject: RE: Concertina action constructions
From: GUEST,chris
Date: 21 Mar 14 - 01:12 PM

I think that you are confusing the action post used by such makers as Wim Wakker and The one made by Rock Chidley - I believe that the post used by Rock Chidley is unique. The post used by Nickolds and Wim Wakker are based on one of the posts illustrated in Wheatstone's 1844 patent. Not sure why Wheatstone's riveted action is more valued than those riveted actions made by George Case and George Jones - same principle. I doubt that Chidley's action has anymore friction issues than the various riveted actions, the lever also rotates around an axle.
Chris

Subject: RE: Concertina action constructions
From: Guran
Date: 22 Mar 14 - 12:45 PM

Chris, in order not to speak aside of each other...YOU are not possibly THE CHRIS (Flint) having written the excellent "Actions" survey?
Anyway...the Wheatstone 1944 patent papers presents two action models, one Fig 3,5 and 5A with a fork post and axle/rivet, another one Fig 16 with a loose saddle connection lever "riding" in a hole in the post. This later model is part of the actual patent being exposed in the text p8 as "my sixth improvement" and the motive being that "the lever can be instantly detached from its bearing to be examined, and the workmanship required is less"
None of these two obviously is the type we mostly are familiar with as the "riveted Wheatstone action" in the period ca 1870-1930s

Despite not being the same the Wheatstone (first Fig 3,5) and one of Rock Chidleys and Wim Wakkers basically should work in the same way and have similar stability and friction characteristics.

Did Nicholds use a similar fork as well? I have seen some Nickolds instrument with a hooked action also.

And yes! - I see no reason meaning that there is any basic difference between common Wheatstone asymmetric riveted model - Case and Jones similar variants. One detali has struck me - I have two Case trebles and the levers on these are dead straight while I think all the same size Wheaatstones I have had have some bent or S shaped levers. This is hardly a crucial matter BUT a straight lever no doubt IS preferable technically. I haven't investigated the possible cause of the difference. With many anglos having a hooked action ( Lachenal type) the U-shaped short levers on 3rd row can be a real nuisance by instability however.

Subject: RE: Concertina action constructions
From: GUEST,chris
Date: 22 Mar 14 - 01:43 PM

Yes I am.
It's possible that the action usually attributed to Lachenal was made/designed by Nickolds, It's also possible that Nickolds made/designed the slotted cylindrical post in the period that he worked for Wheatstone's before Lachenal started there. Nickolds also used another design that looked like a combination of the other two actions. I think that Case and Jones' riveted actions predated Wheatstone's action.
Chidley's action started in 1850 and is unique.
All systems will have flaws. It is a problem with not having a frictionless bearing. As you noted - straight levers are going to be more desirable as they will not cause issues with side wear on action posts, so - look for straight posts with axles supported on both sides. Not sure off hand who has made such an action!
Chris

Subject: RE: Concertina action constructions
From: GUEST,ignoramus
Date: 22 Mar 14 - 02:19 PM

. As you noted - straight levers are going to be more desirable as they will not cause issues with side wear on action posts, so - look for straight posts with axles supported on both sides. Not sure off hand who has made such an action!
Time someone started making them then

Subject: RE: Concertina action constructions
From: Guran
Date: 22 Mar 14 - 03:29 PM

Chris,
Thanks for introducing your5self! And many thanks for your substantial article! Summing up in short as your say: "All systems will have flaws" but maybe wa can discuss a couple of items anyway!

Generally speaking the radial arrangement of reeds and consequent radial arrangement of the action IS asking for mechanical trouble - not to call it a nightmare. It seems obvious from your exhibition that makers have in different ways tried to either effectuate a reasonably technically *good* solution and/or some compromise with
material choice/processing/assembly time/service practise and costs in general. What we experience 100+ years later is also reaults from wear and violent handling of the parts. Some posts for example are terribly breakable or tricky to replace.

It is also rather easy to find conflicts between ideal technology, makers preferences AND *musical* needs from the user and finally needs from the possible repairer...

We probably all agree - as said - that straight levers are desirable, so IS a stable but frictionless connection BUT I would like to point out one detail curious to hear readers reaction to that:
When comparing say common riveted actions with loose saddle connections with the endplates off the difference in stability of the post/lever connection is obvious and it is very easy being fooled by this fact believeing that post/lever stability is an important issue itself. It mostly is not! The stability of *button travel* - which is teh important issue för the player is NOT depending on the lever/post stability but 1) on the accuracy/tolerance between guiding pin and guiding hole and 2) the accuracy/tolerance between button and endplate hole and 3) the distance between ation board and endplate!
It is surprising to me that makers in general have not arranged for better and more adjustable conditions concerning a) button stability b) button travel friction c) button height and damping d) button touch pressure or rather...that demands from players have not stimulated improvements based on these interests

So,"ignoramus", although I agree that technical perfection of the lever and lever/post connection system would be nice I see some other improvements desirable as well from the players viewpoint.

WHAT are the most important factors for the user? And in what ways have these possibly been overlooked to suit maker preferences?

Subject: RE: Concertina action constructions
From: Richard Mellish
Date: 23 Mar 14 - 02:38 PM

Can one of you please provide a link to the "Actions" survey?

I occasionally have to replace a broken button, or just get a button that has slipped out during other work back into position. It can be tricky to get the lever into the hole in the button and then get the pin at the end of the button into the hole in the action plate, all without displacing the felt bush where the lever goes through the hole. A lever that can be temporarily detached from its post would make that job much easier. (But last time I did that job I cheated by using a piece of silicone sleeving instead of felt, and it seems to be OK so far.)

Button pressure obviously depends on the spring and on the ratio of pivot-to-button distance to pivot-to-spring distance. It can be difficult to fit the springs in at exactly the right positions to keep that ratio the same for all the buttons, but in practice when I am playing I am not very aware of different pressures.

Subject: RE: Concertina action constructions
From: Guran
Date: 23 Mar 14 - 04:57 PM

Richard,
Here is the address of Chris Filnt's homepage
http://www.scatesconcertinas.com/

and this is the article on "Actions"
http://www.scatesconcertinas.com/pdf/RE%20ACTIONS%20-%20thinking%20inside%20the%20box%201.pdf

Hopefully with permission and compliments from Chris...:-)

Yes I agree , there certainly are some advantages with a detachable lever and as I said before ...disregarding the technically theoretical superiority of a stable lever/hook connection I doubt that it means a lot for playing standard. BUT as you can see in Chris´s article there are variants with a forked lever AND a stable axle but the parts still being detachable. Maybe one of those would make the ultimate type?? BUT this will not help YOU Richard in this distress getting the parts in place either.
I mostly loosen the pad from the lever in cases like yours, put the button onto the lever, replace and fix the pad again.

Now to the issue of buttom pressure which is another intriguing one with concertinas! The radial and individual lever arrangement is not particularly suited to get the best working mechanism at all. I have suggested several times that for anglos the German type of mechanism layout ( one common axle for all buttons in the same row and the reeds arranged in straight alignment ) makes more sense than the radial variant. This works splendidly for 20 key instruemnts but with 3 or 4 rows the "Chemnitzer" basical construction with reed blocks may be necessary to get things in order.

As a matter of fact button pressure is often quite uneven with many concertinas and players often seem to be unaware of how important it still may be having trimmed button pressures. It IS quite tricky however to set it evenly. You have to use a proper balance and all you can do with the springs is some gymnastics to alter the pre-tension. IF you take your time setting the pressure evenly you will however experience much improved tonal control. With a piano even amateur players use to be quite sensitive to improper "weighing" of the keys.
Talking about superstition with concertinas...there often is talk about lowering the button pressure to "play faster". This of course is a complete misunderstanding. The higher pressure you can manage the faster you may play of course but there is an individual limit naturally and touch dyscomfort from hitting the buttons may become an obstacle.Higher pressure than 100gram is seldom recommendable I think and with many models pads start to leak if getting down to 40 or less.
Some models are more sensitive to low pressure, particularly those with much varying pad sizes where the lower notes start to leak with energetic pumping.
I started a thread on Button size a couple of years ago - this issue is always important IF speaking about button pressure. Not least since there is an enormous difference in playing comfort between 5mm concertina buttons and say 12mm ones as they are on my Hohner melodeon which got a button pressure of over 200gram compared to most concertinas ca 50gram.

Subject: RE: Concertina action constructions
From: GUEST,chris
Date: 23 Mar 14 - 05:00 PM

http://www.scatesconcertinas.com/re-actions-or-thinking-inside-the-box.html
Not a click but copy & paste should do
Also would be worth your while getting a copy of Dave Elliott's 'Concertina Maintenance Manual' - lot more use for help with repairs than my article😀
Chris

Subject: RE: Concertina action constructions
From: Guran
Date: 24 Mar 14 - 03:50 AM

Dave Elliott's manual may be a good help no doubt...still there are a few details in it which are questionable...unless they have been revised in some later edition ( I have only the very first print).

It would be interesting to check if some corrections have been made.
I just mention one important issue - using PVA glue for valves which I would say definitely is NOT recommendable. Starch glue ( wall paper glue) is a lot more suitable. The point is that valves are expected to be replaced several times during the instruments life time and the glue has to be possible to remove easily. In old days laquer was often used (being brittle and easy to scrape away)

Subject: RE: Concertina action constructions
From: Guran
Date: 24 Mar 14 - 03:50 AM

Dave Elliott's manual may be a good help no doubt...still there are a few details in it which are questionable...unless they have been revised in some later edition ( I have only the very first print).

It would be interesting to check if some corrections have been made.
I just mention one important issue - using PVA glue for valves which I would say definitely is NOT recommendable. Starch glue ( wall paper glue) is a lot more suitable. The point is that valves are expected to be replaced several times during the instruments life time and the glue has to be possible to remove easily. In old days laquer was often used (being brittle and easy to scrape away)