On Nov 30, 2010, at 9:14 AM, Susan Kline wrote: > History lesson, please? When did zero friction in hammers start to > seem desirable? Late 18th century, the piano of Mozart and Beethoven, Those axles have near zero friction. As did the keys (no bushings). And there were no intermediate levers with joints and interfaces to produce friction, only the escapement, which had far less friction than the current knuckle/jack arrangement. And pianists were quite capable of playing expressively on those instruments. A more cogent question might be when and why did friction in hammershank/flanges start to be considered desirable and why. Certainly a large part of the answer has to do with firmness of the felt. Clearly there is loss of power and focus when the bushing felt is spongy or there is wobble that you can feel when testing the flange. If you re-pin a standard bushing with standard methods to 0-1 gm, it will almost certainly be wobbly. And it will become more so as the felt packs with wear. So a relatively high friction makes sense as a starting point, for standard technical work. (Perhaps it is somewhat different in manufacture, where methods involve a sizing pin and a wetting agent, producing a reasonably predictable firmness of the final product). Over the years, I have asked a lot of technicians who focus largely on concert work for their view on hammerflange friction. Every one of them has said they don't care if the hammer swings 10 times as long as it is firm, that that aspect is very low on their priority list. And over the years that has sunk in and become part of my mindset. The experiences I have had in re-pinning whole sets of shanks have shown me that the difference is on the level of maybe just being suggestibility. Is there _really_ more control? Is the tonal spectrum _really_ more focused or whatever? I don't know. I'm not sure it made a difference. Going back a year later, sometimes a couple weeks later, I would find that the friction had dropped. Had the control or tone changed? Couldn't prove it by me. OTOH, when I focus on refined travel and square of hammers, level strings and good mating, and refined let off, drop and aftertouch, WOW, that does make a difference perceptible to me and to my customers. So since there is only so much time, and money to pay for that time, I tend to drop re-pinning for friction to a point pretty low on the totem pole. And when I re-pin, I focus more on a firm bushing with lubrication than on a frictional spec. This is not to say that we don't need _some_ friction in a modern action, but exactly where, how much, and why is, well, debatable. My purpose in raising the issue, presenting a different perspective, is to try to get people to have more of an open mind on the subject, rather than rely on some rule of thumb or intellectual construct. Certainly it seems clear that the virtuoso pianists of the world have adapted quite well to Permafree over the past three decades, so it is probably not a disaster <G>. Regards, Fred Sturm University of New Mexico fssturm at unm.edu
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