O.K.. So where in the action do we want NO friction, low friction, and/or moderate friction? And what are Thump --- Richard Brekne <Richard.Brekne@grieg.uib.no> wrote: > This is exactly the point I made to begin with when > I brought up the > <<breaking function>> of friction. This is why > (half of why anyways) we > are looking at a trade-off (in the case of the > hammer shank flange > center) between firmness and friction. The firmer > the better with > regards to hammer contact, opposed to that is the > need for a freely > playing action... but the needed degree of freeness > is limited by the > need for some degree of resistance for the reasons > you describe below. > > And, as you point out, that exact degree will vary > from pianist to > pianist dependant on just how much control they are > able to exert on an > action, and with general styles of playing. > Further... it is no > difficult task to assert that the huge amount of > data on the subject > shows clearly a preference for the kind of friction > levels that have > become the industry standard. > > Cheers > RicB > > > > V T wrote: > > >Hello Friction Thread, > > > >Here is an additional view to get the conversation > >heated up: > > > >The musician has roughly 10 mm of key travel to > apply > >the force to the key. The choice exists of where > on > >the key to push, and how to time the force. If we > >plot a function of finger force vs. time, we will > see > >that the player controls his touch by modulating > this > >force during the travel of the key. There is a > >feedback loop at work and the player integrates the > >force to get the proper momentum into the hammer > head. > > He may start with a higher force to get the static > >friction out of the way, but then he might lessen > the > >force in order to create a soft blow. > > > >The following assumes that the balance weight is > kept > >the same when comparing the low friction to a > normal > >friction action. > > > >All mechanical systems have a "damping ratio". > This > >is a ratio of stored to dissipated energy. Control > >basically amounts to being able to impart just the > >right amount of momentum to the hammer. A > mechanism > >with a low damping ratio (little friction) is > harder > >to control because a mass set into motion without > >friction will continue to move freely. The player > has > >no means to slow the mass down if he initially > presses > >too hard on the key. His skills then consist of > not > >pressing too hard, or quickly backing off in case > he > >did press too hard. This is exactly what a > >"frictionless" action requires - the ability to > change > >finger force in an incredibly short period of time. > > >Again, he has only 10mm of key travel during which > he > >can distribute the force. For best expressiveness, > >the musician would probably like to have as much of > >those 10 mm available to modulate the pressure > without > >feeling that he is moving the key stick through > >molasses. If he doesn't have the physical ability > to > >reduce the force quickly, he will feel that the > action > >is "temperamental". > > > >The situation changes when very fast playing is > >required. The requirement for a precisely > controlled > >dynamic level may give way to the need for speed. > A > >fast (low friction) action becomes advantageous. I > >think that pianists who like to play fast pieces > and > >have phenomenal control over their touch may prefer > an > >action with very low friction. They have the > ability > >to put just the right amount of energy into the > hammer > >in the shortest amount of time, basically using the > >initial stage of the key movement to send the > hammer > >on its way with the precise amount of momentum. > Since > >they did all the work in the initial stage of the > key > >movement, they are free to quickly move on to the > next > >note. > > > >Vladan > > > > > > > >_______________________________ > >Do you Yahoo!? > >Win 1 of 4,000 free domain names from Yahoo! Enter > now. > >http://promotions.yahoo.com/goldrush > >_______________________________________________ > >pianotech list info: > https://www.moypiano.com/resources/#archives > > > > > > > > _______________________________________________ > pianotech list info: > https://www.moypiano.com/resources/#archives > _______________________________ Do you Yahoo!? Win 1 of 4,000 free domain names from Yahoo! Enter now. http://promotions.yahoo.com/goldrush
This PTG archive page provided courtesy of Moy Piano Service, LLC