<DIV>Hello Vladan,</DIV> <DIV>Yes this is a good analysis. Thanks.</DIV> <DIV> </DIV> <DIV>Clyde Allen</DIV> <DIV>Silver Spring, MD V T <pianovt@yahoo.com> wrote:</DIV> <BLOCKQUOTE class=replbq style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #1010ff 2px solid">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 </BLOCKQUOTE>__________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com