At 01:41 PM 12/18/2006, Susan Kline wrote: >Hello, David > >I may be using the wrong term when I say "inertia." >What I mean is that when the hammers bounce way too >easily, the checking will be poor. When they're >this free, as the hammers return to rest you can >see them shuddering up and down several times. >When pinned more firmly, they still bounce some >as they return to rest position, but not in such a >frenetic manner. Not so jittery. Perhaps >they hang around long enough for the backcheck to grab >them better with firmer pinning. Also the tone seems >better. Well, it still does not make sense to me that, given two identical set-ups, the one with firmer pinning would check better on a soft blow. (That the tone is better is not at issue.) Here's why I have difficulty. With tight(er) pinning, the hammer's inertial motion must overcome both the increased pinning friction AND the accompanying greater rep spring tension (not to mention the additional rep spring friction Wim wants to add, with it's attendant increase in spring tension) in order to arrive at the backcheck with enough force to be captured. With low friction at the shankflange center pin, all of that added spring tension is reversed, thus there is less friction and tension for the hammer inertial to overcome and a weaker system trying to lift the hammer. After all, there is no issue of checking if there is no restoring force on the hammer. As to why tighter pinning might help checking? For one, as Ric described and to which you referred, the absence of wobble might help the check hold onto the hammer. Second, if all other things were equal, the low friction assembly would have to move slower (with less inertia) than a tightly pinned one to produce the same level of pianissimo. The pianist would have to work harder to restrain a "fly away" action. To control the moment of hammer / string contact, the low friction unit would have to decelerate more than the tightly pinned one. How's that for unclear? Regarding the "frictionless pinning", I'm willing to be directed to archive or company data which explains the thinking behind it. While greater climate tolerance would make sense from a manufacturing point of view, it would seem a gross expedience, given the implications for its effect on the action's feel and function From my experience, the decreased tolerance in the fit between the shank fork and the flange (bird's eye to bird's eye), which prevented wobble would also, at times, create its own friction source, apart from the pinning itself. Bottom line... Wim's not off the hook! Yet. David Skolnik >I know that extreme freeness in hammer flanges is >the fashion these days, but especially in heavily used >pianos, which soon become looser yet, I think that we >would be better served to pin them to 3 or 4 swings max, >and keep after them as they get up to 6 or more. >It's true that this adds a small amount of downweight, >but it isn't that much, and the feeling of controllability >more than pays for it, IMHO. > >I think that one possible explanation for the present >tendency toward frictionless pinning is that Steinway >sends pianos to many climates. If they leave the factory >with moderate friction and end up in a damp climate, >they will get sluggish. Or if they go to a climate which >has severe humidity changes at different times of year, >more free pinning might seem wiser than firmer. Luckily >Oregon isn't such a place, so I dare set them where I want >them, knowing that they won't start seizing the >following June. > >By all means give me your two possible explanations. >All I've got are my own observations. I think about >the hammer staying around longer, but it's just my >own idea. > >Best, >Susan > >A
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