"David C. Stanwood" wrote: > RicB writes: > > >what, whats significant and whats not, a lot of it contested > >emphatically, and not much of any of it can really be shown to be known > >or adequately quantified one way or the other. > > You can't argue the feelings of pianists and there are plenty who > emphatically like actions with properly applied support springs. Pianists > feelings are an adequate quantity. Yes... I would agree. Where I disagree is that we've properly identified what those tastes really are. There has been no systematic objective approach aimed at identifiying these things. Seems like the closest thing to it is the loosely gathered data that you have... which really says nothing about tastes but more shows an average state of things as they are and have been up to now. Your metrology provides a platform for doing such a study, but thats to be done we need to drop any and all preconceptions about what the result is, look aside from our own preferences and simply do the research. > >But just so we are clear... many if not most assist spring actions these > >days are driving SW levels that are high enough to cause your wrists and > >fingers plenty of problems..... low key inertia or not. > > Most of the actions I've see that cause injury have ratios above 6.0 and SW > in the low high or even top medium zone and too much key lead. As one who > has designed hundreds of assist spring actions I can say that most have SW > in the low to mid high zone which is not at all extreme with ratios in the > mid 5's. As for actions with upper high zone SW, so long as the ratio is > close to 5.0 and the geometry is efficient, there is no pain or injury > there.... This simply doesnt make sense David. I question right off your claim as to being able to identify injury to any particular action configuration... where are the statistics to confirm this.... lets see you even try to present any of this to any medical research body for examination. Nor does key leading, or a 6.0 ratio fit the typical causes for such injuries. Repetitive motion injuries simply are not described as having such causes. Now a 56 gram BW DOES fit, but thats a different matter entirely. Key leading and key inertia is in any case not really an issue here. What problems excessive key inertia can cause are more along the lines of repetition problems, not weight problems. The leads output more force then it takes to accelerate them in all cases because they are (as seen by the finger) on a second class lever ... keyfront (input) --> Balance Rail (fulcrum) --> key Leads (load). Yet that same inertia (key leads) outputs to the capstan relative to the ratio that is defined by the position of the leads and capstan to the balance rail.... which is a first class lever with higher ratio. Its not key leads that hurt your hands... its the net force it takes for the finger to get the hammer up to the string... and the constant banging into the key bed at bottom of the key stroke, and in general bad technique. Assist springs assist only at low levels of play. When you play hard.. the action quickly becomes just as heavy as if they were not there at all. > >they are not being used conciously to cover all ends as it were. > >Basically assist springs are still being used to overdrive the action. > >At least thats how it appears to me. > > >Cheers > >RicB > > I think it might be better said that most technicians think they can fix > actions which are already being overdriven by using wippen support springs. > It doesn't work that easily. You have to address SW and Ratio. > Any action can be made to feel great by balancing hammer weight, ratio, > Front Weight, geometry, and friction. Springs are should be viewed as > extras for getting more performance out of the action. In this we aggree... but as to the specifics of what the above words construe... perhaps we agree less > I've certainly > noticed plenty of comments from pianist who notice that assist spring > actions repeat more surely than non spring actions. > I fail to see what this has to do with the discussion at hand... its another issue relating to assist springs in general to be sure... but we werent off on that track... but when you first bring it up... then I say this.... We need to stop making claims based on such obvious subjectivity. We do this all the time and it gets us no where. If we really want to find out if assist springs help repetition or not.. this is quantifiable. > > As a rule of thumb an assist spring action should play nicely even with the > springs disengaged otherwise the setup isn't right. I would aggree with these words as well. > > > David Stanwood -- Richard Brekne RPT, N.P.T.F. UiB, Bergen, Norway mailto:rbrekne@broadpark.no http://home.broadpark.no/~rbrekne/ricmain.html http://www.hf.uib.no/grieg/personer/cv_RB.html
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