John Hartman Wrote: >Don't 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? John, This is an excerpt from my posting of 1/11/95 regarding precise definition of hammer weight in terms of the newly defined term "Strike Weight". If you haven't read this post, the discussion we've been having in regards to leverage ratio etc might be confusing. I'd be happy to forward you a copy of the posting. Just let me know: STRIKE WEIGHT RANGE GUIDELINES: Note 1 22 44 66 88 14.8-------13.7-------12.1--------9.8---------6.9 F U L L T O N A L P R O J E C T I O N 12.4-------11.5-------10.2--------8.3---------5.8 M E D I U M T O N A L P R O J E C T I O N 10.3--------9.5--------8.4--------6.7---------4.6 L O W T O N A L P R O J E C T I O N 8.0--------7.4--------6.5--------5.2---------3.5 Note: The hammer weight may be found by subtracting the shank strike weight from the strike weight. The shank strike weight is the weight of the shank taken at the strike line radius. Shank strike Weight is generally around 1.8 - 2.0 grams >I certainly can't agree that a heavy hammer is required to have a powerful >tone. I have witnessed many examples of truly powerful pianos with light >cold pressed hammers. I quarantee that if those powerfull pianos with light hammers were put in Symphony hall for use in a piano concerto the result would be a disaster. Think about this: If the strike weight is brought to zero the tonal power will go to zero, so there has to be a point were tonal power diminishes as a function of weight. >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. The relationships that I have given for strike weight and strike ratio are part of a unified touchweight formula that discribes the contribution of each part of the piano action in terms of weight, leverage, and even friction. It is what I am calling "The New Touchweight Metrology". When my key balancing patent is issued the full discription of the formula will be published, and in fact I am close to a point were I may publish before the patent issues. >When all's said and done we may find our selves going back to using hammers >that are neither heavy nor light but just right. We find that hammers over a wide range (as shown in the table above) will work in pianos. The individual situation must dictate what hammer weight is appropriate. The best we can do is collect as much qualitative and quantitative information as we can for a given situation and make the best decision we can make based on analysis of that information. It is certainly in the best interest of pianist to see manufacturers adopt more specific standards than they are currently using with regards to hammer weight, action ratio, and key balancing parameters. David C. Stanwood
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