Jim- What a wonderful post! This could become a great article for the Journal. Perhaps this could be the start of a Guild "basic standard" for hammer replacement. Thank you. Ed Sutton Jim wrote: > Paul would like all the confusion to be removed from this discussion, and > for us to provide him with a simple soultion for optimizing an action. > Paul, try this. > > 1. Start with a well-designed action. Re-designing an action is not what > you are wanting to do. > > 2. Use hammers that are uniformly graduated from bass to treble - no large > or sudden variations in size or weight along the way. That will give you > hammers with evenly graduated mass, bass to treble. > > 3. Use the recommended parts for that particular action. We assumed a > well-designed action to begin with, so maintain the original design, > ratios, spread, clearances, etc. > > 4. Check everything for friction, beginning with the keys alone, befure > you go any further. Keys free to move - no binding - very tiny bit of > side-play at the front bushings - barely enough to feel - no more than that > - no side slap - no binding - no "pulley keys". Check everything else. > Everything snug, nothing loose, but nothing binding, jack centers > absulutely free. Don't worry about whether the shanks are round or > octagonal. It won't matter, as long as you stwy with the correct > dimensions and high-quality parts. I'm talking about the keys and action, > not the back-action or dampers. That's another matter. > > 5. Do a preliminary action regulation. Double-check for any possible > problems, especially any tight centers or bushings, or anything loose. > Deal with all that stuff first. > > 6. Weigh off for even BALANCE WEIGHT (down-weight + up-weight / 2). The > actual balance weight I aim for will depend upon what the piano owner > wants. If you have done the preliminary things well, you will find that > there won't be any big differences in balance weight and up-weight from key > to key after you check the down weight. There will always be some. But if > you aim for even balance weight, you won't be way off when the friction > changes, as it will surely do, sooner or later. > > If you follow this routine, you will end up with an action that has an even > response from bass to treble. But if you start with hammers that are not > uniformly graduated from bass to treble, and friction that is not > consistent, and then try to compensate for it with the key leads, I can > assure you that you will end up with an action that does NOT have a > consistent feel from key to key. > > David Stanwood has a patented system for doing this that we have all read > about or seen. I have my own system, different from David's, that I was > privately developing when David first come on the scene. Mine is still > under development, so I won't go into it right here on this list. I have > not yet decided what to do with it. > > But Paul, if you will follow the simple procedure I outlined, you will end > up with an action that is consistent from bass to treble, and you will not > infringe upon anyone's patent claims. You will just be doing what has > already been done for years, but you will be doing it well. From time to > time, some manufacturers have not been as careful as they should have been. > > The problems I often find in old pianos are: > > 1. The hammer weights were not uniformly graduated to start with. > 2. The friction was not uniform to start with. > 3. The factory tech tried to compensate with key leads. > > The result was that the down-weight might be even, but the key-to-key > action response would not be even throughout the dynamic range, and no > amount of regulation would make it so. Furthermore, when the friction > changed, the down weight would be uneven. > > Sincerely, Jim Ellis > > > _______________________________________________ > caut list info: https://www.moypiano.com/resources/#archives >
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