goran rahm Posted November 29, 2003 Share Posted November 29, 2003 Rich, Goran, Dave! I am wondering if there is a clash of terminology somewhere, your loadings seem to vary by a factor of 100x Can you agree that the load you are discussing is: the static load applied axially to the key that is required to hold the key part depressed and with the pad just off its seating? If all parties report in 'YES' then at least we are comparing apples with apples Dave Goran:Reporting 'YES' ....conditionally I understand what you are saying.. :-)....keeping in mind that *I* don't speak English..... When testing ambitiously I use to check 1)the 'depressing force' ,2)the slightly smaller 'returning force' 3)and a 'balancing force' admitting the button to move freely within the travel play....since there is some friction involved Since I use a balance with "weights" I have not calibration problems Goran Link to comment Share on other sites More sharing options...
d.elliott Posted November 30, 2003 Share Posted November 30, 2003 Rich, Yes Load = overall 'force', in my terms the 'physical weight', in grammes, ounces, milligrammes, pennyweights or any other unit you care to mention. We don't need the complication of 'g' multiplication factors! Calibration would be useful, your device might not be linear, and the scale might be only indicative. Actually I suspect there a decimal place out in a conversion factor somewhere. Goran, your English never ceases to astound me, again I take you back to the word 'Load' a mass, or lump applied to or rested on something. Eliminating the further complication of pressure and contact area on the key top. And Gentlemen all, we are all looking at a position of static equilibrium where the pad is just lifted? Finally Jim, with all these liguistic conumdra, as long as the apples are not French Golden Delicious, who cares? Tin Hat is now on Dave Link to comment Share on other sites More sharing options...
Dave Prebble Posted November 30, 2003 Author Share Posted November 30, 2003 Hi to all, My main objective in starting this thread was to explore simple methods of achieving consistent results when re-springing an action. I fully accept Goran’s point of view that actual readings in standard units such as grams or ounces are essential to meaningful discussion should, as has happened, the argument progress beyond the original parameters. I don’t propose to discuss actual forces in grams until Richard has been able to check his instrument calibration. In order that we are all 'singing off the same hymn sheet' in future discussion, my definition of ‘touch weight’ would be as follows: ‘That static weight, (shall we say in grams?) which, when placed on the tip of a vertical button, is just sufficient to cause that button to move and thus operate the lever and start to lift the pad. I’m happy to accept Dave E’s definition and thus disregard any minor differences between static and dynamic coefficients of friction. Busy now……more to follow Regards Dave Link to comment Share on other sites More sharing options...
Richard Morse Posted December 1, 2003 Share Posted December 1, 2003 (edited) Now that I've been into our shop and personally checked out our force gauge -- I'm quite chagrined.... It is as simplistic as I had remembered, but it turns out that the gradations we were using are in ounces, not grams! Also, I calibrated it with our digital postage scale which shows it to be a bit low. So! Converting all the above into currentness yields that our observations for concertina button "touch weight" seems to fall in the range from 50 - 100 grams which is completely in keeping with Goran's observations. We set our concertinas to about 70 grams. For those interested in our force measuring device, it is made by Jonard, their "economy" model. While I was on their website, I also saw a much more enticing and sensitive dial model, not to mention considerably more expensive. Edited December 2, 2003 by Richard Morse Link to comment Share on other sites More sharing options...
goran rahm Posted December 2, 2003 Share Posted December 2, 2003 Thanks Rich...now we're 'on speaking terms again' :-) so may I return to some of the previous items.. Your 70 grams seems to be somewhere in the middle then and one of my questions related to the 'tolerances'..(and your experience from customers...) a) 'downwards' ..to secure tightness (which of course is also depending on playing style) 'upwards' since I/"we"(!) might want 'as fast an action as possible' and touch comfort sets a limit c) 'downwards' as some players want a 'light' action for comfort which comes in conflict with a) Now....You mentioned (if I got you right...) that in order to secure tightness AND still preserving a 'light touch' you could adjust with the fulcrum (locating it more distantly I assume) BUT as far as I understand these possibilities are very limited since you would get a longer button travel to open the pad fully and this also may soon come into conflict with the requirements for opening area....(or does it not??) In principle we want to make sure that no 'channel' part is more narrow than the maximun air passagearea in the reed slot. This may yet not be enough since it can be easily detected that a somewhat (not so very much..) too close pad may dampen or change the sound. The 'traditional' tolerances are not very wide. The Wheatstones I have checked 'never' originally are set with a button travel less than 3,2 mm (and sixsided often don't tolerate more than 3,5-3,6 due to the short guiding pins) The pad opening area of course is depending on the pad thickness too but there is not much variation admittance here either. So..Rich...If your construction is basically the 'traditional' type ...have you come to any 'better' solutions/variants than the old ones? Longer button travel? Other reeds and passage areas? ...otherwise I see small chances to do much about it Dave, You mentioned adding a second spring in the lower range to secure tightness.This is a dilemma too, since you definitely do not want a much varying 'button resistance' and not much variating 'button travel' either when playing do you? At last a favourite of mine: Button size ....it doesn't help much for solving these above conflicts ....except that a wider button area does admit using stronger springs with the same (or even better) comfort. Compare the Hohner 200+ grams again and its 12mm buttons which cause me no discomfort at all. Therefore:....Since we do have technical limits 'downwards' for spring force .... instead of using softer springs when 'lighter touch' is asked for I suggest that wider buttons are tried. Generally speaking the 'comfort preferrence size' for 'touch buttons' use to be (10)12-15mm so we have a bit to go in that direction.... One of the conclusions I make from this issue is that these mechanism related factors add to the impression that 'wide range' concertinas are monsters with usually little justification. The smaller range - the 'better' instrument!! Nevertheless the 64 key baritone-treble used to be my favourite..... Goran Rahm Link to comment Share on other sites More sharing options...
Clive Thorne Posted December 2, 2003 Share Posted December 2, 2003 We had a fairly long thread about button sizes about two years ago, and some argued (me included) that 'large buttons' were not appropriate on concertina except perhaps on 20 key instruments. It all comes down to finger size, button size and key to key centre distances. Computer keyboards and (for different reasons) even melodeon keyboards are not comparable to concertina keyboards. Obviously, Goran, you were not convinced by the arguments at the time, so its probably not worth re-iterating them here. Clive. Link to comment Share on other sites More sharing options...
JimLucas Posted December 2, 2003 Share Posted December 2, 2003 ...gradations we were using are in ounces, not grams!... For those not familiar with ounces, 1 oz.(ounce) = 28.35 g (approximately). Link to comment Share on other sites More sharing options...
JimLucas Posted December 2, 2003 Share Posted December 2, 2003 Thanks Rich...now we're 'on speaking terms again' :-) Don't push your luck Göran! (Half-sincere apologies to everyone, especially Göran, but given the subject of this Topic, I couldn't resist the pun. ) Link to comment Share on other sites More sharing options...
JimLucas Posted December 2, 2003 Share Posted December 2, 2003 The smaller range - the 'better' instrument!! Hmm. Could I interest you in a one-button concertina? English/duet, of course, since two different notes of an anglo would be a larger "range" than one. OK, after two joking responses, I'm about to make serious one. Look for it as a new Topic, relating to button size... and more. Link to comment Share on other sites More sharing options...
Richard Morse Posted December 2, 2003 Share Posted December 2, 2003 in order to secure tightness AND still preserving a 'light touch' you could adjust with the fulcrum (locating it more distantly I assume) "More distantly" from what? From the button end? Please be more clear. BUT as far as I understand these possibilities are very limited since you would get a longer button travel to open the pad fully The only way to get a longer button travel would be to have longer buttons that stood proud of the end more AND had a higher shoulder (if that is the way their designed), AND have a longer stem, AND had a deeper socket. IOW, given that the button and it's path doesn't change, moving the fulcrum point will not allow the button travel distance to be any different. and this also may soon come into conflict with the requirements for opening area....(or does it not??) Where is the opening area conflict if the pad can be "opened fully"? The pad opening area of course is depending on the pad thickness I don't understand. The pad does *cover* an area, but that has nothing (well, maybe but for some small structural issues) to do with the pad's thickness. And the hole the pad covers can vary significantly from the size of the pad. Maybe you're concerned about the pad being so thick that it hits the underside of the concertina end? If your construction is basically the 'traditional' type ...have you come to any 'better' solutions/variants than the old ones? No. We tried quite several novel action designs and ultimately settled on the the "traditional" as being the most cost-effective for the quality we wanted. It is sufficiently tweakable for us to get the results we want. Longer button travel? Other reeds and passage areas? ...otherwise I see small chances to do much about it Other than being fastidious in our attention to the forces, travel distances and clearances (which are NOT improvements, just making the most out of the situation), we have been able to make improvements with lighter buttons (less mass responds - moves - easier = quicker) and reduced friction (for speed of response) than most vintage concertinas have. Link to comment Share on other sites More sharing options...
Richard Morse Posted December 2, 2003 Share Posted December 2, 2003 One of the conclusions I make from this issue [of button size?] is that these mechanism related factors add to the impression that 'wide range' concertinas are monsters with usually little justification. I don't see what the action mechanism has to do with the range of a concertina. How does button size or action make a wide-range concertina a monster? The smaller range - the 'better' instrument!! That is your opinion, but maybe you are content to play tunes with only a few notes notes in a single key? Link to comment Share on other sites More sharing options...
goran rahm Posted December 2, 2003 Share Posted December 2, 2003 QUOTE (Goran) in order to secure tightness AND still preserving a 'light touch' you could adjust with the fulcrum (locating it more distantly I assume) Rich:"More distantly" from what? From the button end? Please be more clear. Goran: Sorry...'distant'from the button...'closer' to the pad....changing your leverage "3:5 " to 1:1 or 5:3 just as an example...You mentioned yourself (I don't quote..) that the problem with low range pads leaking could be counteracted by different leverage QUOTE BUT as far as I understand these possibilities are very limited since you would get a longer button travel to open the pad fully Rich:The only way to get a longer button travel would be to have longer buttons that stood proud of the end more AND had a higher shoulder (if that is the way their designed), AND have a longer stem, AND had a deeper socket. IOW, given that the button and it's path doesn't change, moving the fulcrum point will not allow the button travel distance to be any different. Goran:Now I don't understand you again...If you move the fulcrum point (which changes the leverage) you inevitably increase the button travel for the same pad travel and a certain pad travel is necessary not to decrease the airflow and possibly also change the tonal characteristics QUOTE (Goran) and this also may soon come into conflict with the requirements for opening area....(or does it not??) Rich:Where is the opening area conflict if the pad can be "opened fully"? Goran:Late paragraph...you have to secure that the pad does open *enough* and this may become difficult since there sometimes is little tolerance for reduction. With Anglos there often is excessive opening of the pads in the lower range but not with Englishes or Duets QUOTE (Goran) The pad opening area of course is depending on the pad thickness Rich:I don't understand. The pad does *cover* an area, but that has nothing (well, maybe but for some small structural issues) to do with the pad's thickness. And the hole the pad covers can vary significantly from the size of the pad. Maybe you're concerned about the pad being so thick that it hits the underside of the concertina end? Goran:Assuming that you have your basic 'construction' unchanged and wish to laborate with these mechanism factors you can not applicate a thicker pad without interfering with the opening area since your button travel does not admit much more lift of the lever (and pad) QUOTE If your construction is basically the 'traditional' type ...have you come to any 'better' solutions/variants than the old ones? Rich:No. We tried quite several novel action designs and ultimately settled on the the "traditional" as being the most cost-effective for the quality we wanted. It is sufficiently tweakable for us to get the results we want. Goran: Then what makes it possible for You do you mean to achieve 'lighter' button resistance as I understood you said earlier. Well....now if you use 70 gram it is not any lighter than the traditional but I got the impression you had managed to reduce it to less than the traditional... Maybe I got that wrong somehow... QUOTE Longer button travel? Other reeds and passage areas? ...otherwise I see small chances to do much about it Rich: Other than being fastidious in our attention to the forces, travel distances and clearances (which are NOT improvements, just making the most out of the situation), we have been able to make improvements with lighter buttons (less mass responds - moves - easier = quicker) and reduced friction (for speed of response) than most vintage concertinas have. Goran: What do you buttons weigh then? And what material causes less friction? or have you firstly polished them in some special way? Yes..friction may be essential...weight....Hmm...I don't really know..compared to the 'button resistance' of 70 gram I hardly believe it matters much if a button weighs 1 gram or 2(like all-metal ones may do) I actually believe the button weight mostly has psychologic influence as well as influence on the effort to 'carry' the instrument. Of course...at extreme speed maybe you notice some difference possibly related to the inertia..but still..I doubt it Would be interesting to make a 'blind test' which actually could be done in this case..... Goran Rahm Link to comment Share on other sites More sharing options...
goran rahm Posted December 2, 2003 Share Posted December 2, 2003 QUOTE (Goran) One of the conclusions I make from this issue [of button size?] is that these mechanism related factors add to the impression that 'wide range' concertinas are monsters with usually little justification. Rich:I don't see what the action mechanism has to do with the range of a concertina. How does button size or action make a wide-range concertina a monster? Goran:The conditions limiting optimal solutions for button travel, button resistance, leverage, pad opening, pad tightness have different impact in the 'top' range and 'low' range and the ideal solutions are not fully compatible. The situation is the same concerning end size (deciding pumping 'effort' and tonal control) which is decided firstly by the number of notes (=range) and concerning space demands from reeds mostly with wide range instruments resulting in not sucessful combinations of 'long scale' reeds and 'shortened' ones. QUOTE The smaller range - the 'better' instrument!! Rich:That is your opinion, but maybe you are content to play tunes with only a few notes notes in a single key? Goran: You easier manage acccording to the above to make a small range instrument 'evenly' purposeful within its limits. Seems as if the 40-48 key 'concept' for Englishes for example is 'good' but 64+ key instruments suffer from 'overgrowth'.For Duets about 55 keys make a similar limit and Anglos with more than 30 keys often start being 'crowded' too.... Goran Rahm Link to comment Share on other sites More sharing options...
JimLucas Posted December 2, 2003 Share Posted December 2, 2003 Seems as if the 40-48 key 'concept' for Englishes for example is 'good' but 64+ key instruments suffer from 'overgrowth'.For Duets about 55 keys make a similar limit and Anglos with more than 30 keys often start being 'crowded' too.... FWIW, I find my 45-button Jeffries the most comfortable of all my anglos to play (more so even than my super-light Ceili)... and I am not the only one who feels that way about it. Link to comment Share on other sites More sharing options...
Richard Morse Posted December 3, 2003 Share Posted December 3, 2003 BUT as far as I understand these possibilities are very limited since you would get a longer button travel to open the pad fully given that the button and it's path doesn't change, moving the fulcrum point will not allow the button travel distance to be any different.Now I don't understand you again...If you move the fulcrum point ... you inevitably increase the button travel for the same pad travel Maybe if I rewrote your sentence above you will see what I mean.... "If you move the fulcrum point closer to the pad you inevitably increase the button travel for the same pad travel because the button will now travel upwards through the end of the concertina and downwards through the action board". You can see that I was pointing out that there are conditions that will not allow the button to move more that it was designed and constructed to move. If you move the fulcrum point nearer to the pad end the button will still travel just as much as it did previously though the pad would travel less. The pad opening area of course is depending on the pad thickness I still don't understand your reply. What is the "pad opening area" and what does the pad thickness have to do with it? Link to comment Share on other sites More sharing options...
JimLucas Posted December 3, 2003 Share Posted December 3, 2003 The pad opening area of course is depending on the pad thickness I still don't understand your reply. What is the "pad opening area" and what does the pad thickness have to do with it? I'm guessing here, but could Göran be suggesting that if the pad lift above the hole is extremely small, it will restrict the air flow? Such "choking" can be used to "bend" notes on accordions and concertinas (by depressing the button only slightly), though I've never been able to do it reliably, myself. On the other hand, while in theory it may be a design constraint, I would expect that any practical design would have enough lift to avoid that limit for any reasonable pad thickness. Link to comment Share on other sites More sharing options...
goran rahm Posted December 3, 2003 Share Posted December 3, 2003 Goran now:Hmm...another communication problem seemingly has arrived. I willingly blame myself if vaguely expressed. I'll try to sort it out: Goran before:BUT as far as I understand these possibilities are very limited since you would get a longer button travel to open the pad fully QUOTE (Rich) given that the button and it's path doesn't change, moving the fulcrum point will not allow the button travel distance to be any different. QUOTE (Goran) Now I don't understand you again...If you move the fulcrum point ... you inevitably increase the button travel for the same pad travel Rich latest:Maybe if I rewrote your sentence above you will see what I mean.... "If you move the fulcrum point closer to the pad you inevitably increase the button travel for the same pad travel because the button will now travel upwards through the end of the concertina and downwards through the action board". You can see that I was pointing out that there are conditions that will not allow the button to move more that it was designed and constructed to move. If you move the fulcrum point nearer to the pad end the button will still travel just as much as it did previously though the pad would travel less. Goran now: I can't see there is any difference except in that you assume that other factors are unchanged and I left them out. The point of the discussion being that you can not normally execute your proposed relocation of the fulcrum unless either: 1) reducing pad opening area (which *may* be negative) 2) getting a longer button travel (which may be negative also or at least demand other contruction/design changes (compared to the "traditional" concept) QUOTE (Goran) The pad opening area of course is depending on the pad thickness Rich:I still don't understand your reply. What is the "pad opening area" and what does the pad thickness have to do with it? Goran now: Since You Rich seemed to presuppose that the "traditional" construction is used (or your own variant of it) you have fixed measures for the involved parts and in that case introduction of thicker pad will reduce the air passage area (the imaginary mantle surface between the pad circumference and the the circumference of the pad hole = "pad opening area" as I called it before) There are limited tolerances for reduction of this area. You may choke the air passage itself and there may be influences on the amplitude and tonal spectrum. Goran Rahm Link to comment Share on other sites More sharing options...
goran rahm Posted December 3, 2003 Share Posted December 3, 2003 QUOTE (Richard Morse @ Dec 2 2003, 07:17 PM) QUOTE (Goran) Goran)The pad opening area of course is depending on the pad thickness (Rich)I still don't understand your reply. What is the "pad opening area" and what does the pad thickness have to do with it? Jim:I'm guessing here, but could Göran be suggesting that if the pad lift above the hole is extremely small, it will restrict the air flow? Such "choking" can be used to "bend" notes on accordions and concertinas (by depressing the button only slightly), though I've never been able to do it reliably, myself. Goran: One side of it ...see my reply to Rich Jim:On the other hand, while in theory it may be a design constraint, I would expect that any practical design would have enough lift to avoid that limit for any reasonable pad thickness. Goran:You *may* succeed to compensate by changing the basic=traditional construction/design but my point is that the resources for this are very small if you stick within the 'traditional concept'. If some parts and measures are changed however it may be easier. This means for example: 1 A larger instrument overall 2 Longer and more variated levers 3 Admittance for longer button travel 3.1 longer buttons 3.2 longer guiding pins and holes 3.3 increased distance between end and action board 4 Another differentiation of leverages 5 Possibly differentiation of spring resistance or another type of spring action The trick is whether such changes are 'musically' favourable or not and what other demands may come in conflict with each other Goran Rahm Link to comment Share on other sites More sharing options...
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