On 8/1/05 12:10 PM, "David Love" <davidlovepianos@comcast.net> wrote: > If you measure the up and down weight on the notes you are sampling you will > be able to calculate the friction and know instantly whether you have a > friction problem or not. > > David Love > davidlovepianos@comcast.net Yes, and that would certainly be a first step in looking at an action for the first time and doing a preliminary analysis. But it is very time-consuming to go through the whole piano, writing all that down and calculating BW and so forth. If you do this prior to addressing frictional issues, it is a very inefficient approach, in my experience. For instance, if there are major frictional issues (could be vertigris-like, could be loose knuckle leather, felt knuckles, a number of other possibilities), the BW one calculates from the DW and UW will not be the same as the one obtained after addressing the frictional issues. Theoretically the friction should be calculable from DW and UW, and within limits it is. But I have found on more than one occasion that a piano I diagnosed as having too high a BW from initial readings turned out to be not so bad after addressing friction. IOW, the calculated friction was not the same as the actual friction, and reducing it took more from the "high side" than the low (of the difference between DW and UW). That's my experience, and is one thing that has led me to a different approach: get the action within parameters first, before drawing any conclusions. Charting DW, UW, BW, etc comes after the action (or samples in the action) has had issues addressed. Regards, Fred Sturm University of New Mexico
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