Alright, I've examined my conscience. Forgive me, my experience is the same as Ken's with regards the heavy versus light feel. The complaints about not enough resistance are usually due to friction. I am in these posts only talking about using "Genuine Steinway Parts". Static Friction is defined as the force that is provided to a mass object that successfully prevents its motion. In other words, as soon as there is movement Static Friction no longer has any effect. Kinetic Friction or Moving Friction is, as its name suggests, the force provided to a mass object that resists the direction of the motion of the mass object. Experiments will verify that the magnitude of the Static Friction Force is greater than the magnitude of the Kinetic Friction. A little head reasoning should convince one that this is true in general. Kinetic Friction does not change as the speed changes. However, in the case of a grand action the magnitude of the Kinetic Friction force will changes as the hammer moves through its arc. This is due to the change of the direction of its gravity vector. At near rest position the weight of the hammer shank assembly is shared between in fixed amounts between the hammershank center pin and the rest position of the knuckle on the whippen. As the hammer moves towards the top of its arc of travel more of the weight is supported by the whippen (creating more friction at the knuckle) and less weight is supported by the hammershank center pin. What this really means is that Angular acceleration of the the Hammer is not constant due to the changes of friction. This complicates any attempt to measure it and one can only hope for some sort of equivalent meaningful measurement. I have verified through experimentation these results. I have found that the hammer accelerates quite nicely through the first half of its arc and decelerates in the last half of its arc. Probably one should be concerned about this first half since the final speed of the shank upon impact is dependent of the acceleration of the first half. I'm going to bow out of these Internet discussions for a while. I am presently taking a course in Partial Differential Equations and Fourier Analysis. Its very hard and requires all my theoretical free time to do the homework problems. So it competes with PianoTech. See you in March! Michael Wathen College-Conservatory of Music University of Cincinnati
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