At 19:51 -0700 22/6/10, Don Mannino wrote: >There are other issues with the adjustable screw for the "butterfly" style >repetition springs. Not issues that make them bad or unusable, but they do >affect the feel and the performance of the action. > >In the original system, the repetition spring normally slides out the groove >on the repetition lever. This changes the point of contact of the spring on >the lever, moving away from the lever center and towards the knuckle, while >gradually increasing the spring resistance. > >In the screw-adjustable system, the contact point of the spring on the lever >remains the same, but the spring length becomes shorter as the spring is >compressed. This changes the rate at which the spring stiffness increases, >and also does not "soften" the affect of the spring's stiffening by sliding >the contact point closer to the knuckle. Don, I find your reasoning a bit far-fetched. By the "original system" I suppose you mean Steinway's variant of the Erard-Herz action. Many, if not most, levers made by the best German and French makers around 1900, before an almost universal switch to the Schwander B action for the next 70 years or so, had cloth pulled, like a bushing, across the groove to serve as a fixed bearing for the spring. This method, apart from giving lower and more uniform friction and simplifying lubrication, eliminates the peculiarity you refer to as a virtue. I don't see it as a virtue and am sure the only reason Steinways did it the way they did was to pare costs, just as they make the lever heel integral with the rider instead of going to the extra expense other makers go to of having a separate heel with the grain running vertical and not liable, as Steinway's design is, to expansion with humidity. >Finally, the spring force ratio between the repetition lever / knuckle and >the jack is also affected. This is of less consequence than the rate of >spring tension increase, but has an impact on the overall force which the >spring applies to the capstan during repetition. > >The end result of all this is that the touch is affected in a small way. I think small, and insignificantly small at that, is the operative word here. I am sure it was never intended to be significant. > I installed 3 sets of these wippens in the 80s when they were >first offered by Renner, and went back to the normal design because >I didn't care for the touch, and felt that the repetition was not as >good unless the springs were regulated strong enough to make the >hammer rise quite fast. The hammer lift was then bothersome during >soft playing at times, detectable by the player. I don't know what Renner was offering in the '80s. My Renner catalogue is from the '70s and the only lever they list is the Schwander B type with the long spring and the loop on the jack. >So, for these reasons, many people (and piano companies) prefer to use the >old "PITA" style of wippens, even though the new design is certainly much >simpler to regulate. I think it is purely a question of fashion and, of course, Steinway-imitation. When I began in the trade nearly all grands, including Kawai, used the Schwander B type action and Bechstein was market leader for two generations with the same action until they badly botched their PR during the war. I must admit I do personally prefer the old Erard-Herz lever to the Schwander B, though I prefer Herrburger's 1899 action to either of them, but the additions used by Ibach and Grotrian in the early 1900s to facilitate the adjustment of the springs were excellent. In recent times Schimmel have also used their own adjustable variant, which I haven't much experience with, and I'm sure there are others. JD
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