David, Dont you think it would be better to refer to hammer weight in terms of actual grams instead of using imprecise terms like heavy or light? A discussion of real hammer weights would be helpful. May I suggest that the hammers weight be included with the up and down weights and leverage within the test note framework. I have been following the discussion of the relation ship between hammer weight and tone. One aspect of this that can contribute to confusion is the fact that heavy hammers are usually hot-pressed and are very hard (read stiff) while light hammers are cold-pressed and require hardeners in order to deliver their best tone. In order to compare the volume of tone potential between light hammers and heavy hammers this difference has to be nullified. I am not surprised that many techs have come to believe that heavy hammers are superior to light ones. Voicing hot pressed hammers requires only the application of needle voicing. A practice that is well understood, easy to do and approved by all in our field. On the other hand the process of building the tone into a cold pressed hammer requires the careful and skilled application of hardeners; a process not well understood within the community of technicians. In addition there is continuing and growing condemnation of the process primarily stirred up by ignorance and by dealers of imported hammers. I certainly cant agree that a heavy hammer is requires to have a powerful tone. I have witnessed many examples of truly powerful pianos with light cold pressed hammers. Of course I have also seen many examples of powerful heavy hot-pressed hammered pianos as well. What these pianos have in common is more interesting to me than the issue of what hammers they have. The above in no way alters the importance of the relationship between hammer weight and leverage that you have been working on. At the bottom of this is probably some very simple and elegant relationship between leverage, hammer weight and friction and some sort of equilibrium between, key acceleration, hammers acceleration and the hammer's compliance. In fact I would guess that the piano action, as we know it, is the expression of these relationships. Our theory is now catching up with the evolutionary process that created the modern piano. In spite of the importance of the theory I cant help but wonder if we are going in circles about hammer weight. Most of us have tried making the hammers lighter, and yes it made a difference. And some of us also tried heavier hammers and again there was some improvement. Either way there was a trade off between how well the action functioned and the tone and naturally we learned a lot about how the action works. When alls said and done we may find our selves going back to using hammers that are neither heavy nor light but just right. John Hartman P.S. At last years convention I saw some hammers that where truly light. The salesman was very proud that his company had finally perfected, after several years of development, these new feather light hammers specifically for the American technician as replacement hammers. I didnt have the heart to tell him that they were too late; most of us have gone on to using heavier than average hammers. It pays to stay informed.
This PTG archive page provided courtesy of Moy Piano Service, LLC