On Aug 14, 2009, at 5:02 PM, Chris Solliday wrote: > Jeff T. is right when he says sluggish pinning of rep lever and > jacks or weak springs are problems, well yes, that is obvious, but > it's when the balancier is too loose that the real trouble begins. > No matter how tightly you adjust that spring it can be pushed down > by a heavy hammer returning on a heavy blow. Disaster. Pin balancier > centers 4-9 grams (depending on how high your humidity gets in the > summer) for best results. I know that a number of people have been advocating for tight pinning of balanciers, on grounds that it makes for better rep spring regulation and function. I am going to express a bit of skepticism about this. Granted, it will make it easier to do a bench regulation. Will it, in fact, make for better function? In real life piano playing, things are quite different from the artificially created bench regulation procedure of watching the hammer rise from check. One element of tighter centers is an obvious beefed up spring (to overcome the added friction). In playing the key, the way you feel that increase in spring tension as touch is in increased resistance at the bottom of the keystroke, so if drop and/or aftertouch are even somewhat excessive, this means a significantly more heavy/resistant feeling action. Less so if drop and aftertouch are minimal, but still noticeable. So there is a potential negative effect on touch, on the feel of the action. What actually happens during real life action function? The spring acts at the drop screw and the wipp cushion, pushing them apart, thus pushing the key back up (well, the back of the key down, hence the front of the key up). And then (after a microsecond) it also acts at the knuckle and wipp cushion, doing the same. Result is the key being returned faster, and the wipp also being accelerated. But the hammer/ knuckle are, especially on hard blows, rebounding faster than all this other stuff is happening. Does the extra spring tension cause the knuckle/shank/hammer to slow down relative to the wipp/key? On a hard blow, I doubt it does so significantly, but I don't know. It probably speeds up the key/wipp return. But the hammer/shank/knuckle probably have enough mass and impetus to cut through, if the check is out of the way. And here is where I think (but don't know) CAF happens: if the key is activated in such a way that it is released before check happens, the check may actually get out of the way. And, yes, I think this does happen sometimes. Here we are in the realm of high speed playing where the key bottoms before the hammer starts rising, as many of us have seen in films by Birkett or read about in the Five Lectures book. The key has been activated, and the finger has moved on to other things. The whole action assembly continues its function autonomously. Or maybe the finger re-enters the picture, re-playing that key at some unpredictable moment in the flurry of activity. The fact is, we don't really know what is going on, because we can't see it. We see a few high speed films that tell us a little, about things like the jack bouncing back and forth against the knuckle (especially if there is too much play between it and the rep window cushion), about flex in keys and shanks, lots of different elements. But do we really have a good take on how the whole action resets itself in every circumstance (different types of blow, different follow through actions like either rapid repetition or lazy finger letting up the key, all kinds of variables)? Bottom line, I think it is an oversimplification to theorize that heavy rep pinning is a magic formula that cures all ills. Yes, that is an exaggeration of what people are saying, and I certainly mean no offense. I just think we need to look at all this with a humble and skeptical eye. We don't really know. At least _I_ don't really know. In my own work, I haven't found heavy rep pinning to be nearly as beneficial as people say - except in making bench regulation a little easier to do to spec. For me, the jury is still out on whether or not heavy pinning of reps is positive, or positive enough to be worth the trouble. I was pretty skeptical about the notion that hammerflanges at under 4 grams (in most new Steinways at 0-2 grams) would meet my theoretical notions of how actions ought to work. A few years of fooling with actions at those specs has made me re-think my theories. I am no longer convinced that a 4 gram hammer center functions better than a 1 gram one, assuming both are firm. And since I really don't find it that hard to adjust rep springs with looser pinning (years of practice, like tuning unisons), the improvement from heavier pinning needs to be pretty positive for function to make me want to do it as a matter of course. I have done it experimentally, and haven't noticed a difference - that is, a positive difference in function. I have noticed a difference in feel, that I haven't liked. Just a different perspective on this whole rep center pinning thing, in hopes of stimulating some thought. Regards, Fred Sturm University of New Mexico fssturm at unm.edu -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://ptg.org/pipermail/caut.php/attachments/20090814/f4998779/attachment-0001.htm>
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