On 9/28/97, Delwin D Fandrich, pianobuilders@olynet.com wrote: >David, > >Yes well, just like with the sometimes inappropriate changes made to >action geometry, not all rescaling work is done correctly. Golly Del, that remark seems to beg a discussion of "inappropriate changes made to action geometry". Certainly, it's well understood that in the matter of string scales, the inharmonicity introduced simply by coupling these srtings to a (relatively) massive soundboard panel is not going to be adjusted by changing wre sizes, etc. Nor is the business of soundboard induced inharmonicity going to reduce itself to simple formulas as neatly as is the strings' intrinsic inharmonicity. As to "changes made to action geometry", the consequences of inappropriate changes are eseentially mechanical, and (because I can understand them) not terribly complicated. The trouble we can get into is limited to 1.) setting a key ratio which may put too long keystick of a long grand under too much stress (and risk of failure), and 2.) accepting a strike ratio solution to a hammer weight problem which for its execution requires to deep a keydip . In the work that David Stanwood (and I, as his student ) do, screwing with the action srpead doesn't count for much. (Remember, gang, that the 3:2 ratio of the rep lever is not the most effective place to make a change in overall leverage, but more importantly, changing the spread, ie. moving the rep center back or front, is moving the contact points -at the cap and the knuckle- in the same direction and are not changing the rep's leverage ratio.) Yet if there is one palce where the motion of parts can be moved out of comfortable working tolerances (and into jacks crushing into the front end of rep lever windows), the spread is where you can get into trouble the fastest. Sacred cows and divine burgers. Ten years ago, Ken Sloane published in the PTJ an description of how a heavy S&S D action was cured with a set of shanks whose knuckle mounting made the "jack-parrallel-to knuckle-molding" impossible. He did sort of miss that nifty aligmnet while he was looking at it during that step oif the regulation. But what those shanks did for the action resistence was far more important than some traditional benchmark (which by the time the pianist sat down at it was burrieds deep inside the action.) I've got plenty to learn here and am an eager student. So, when we've straightened out that the proof of a good rescaling is not how it looks coming out of the printer, but how it sounds when the pianist sits downat the finished product, we can move on to "inappropriate changes made to action geometry". I'm all curled up at your feet and waiting <g> Bill Ballard, RPT New Hampshire Chapter, PTG "You'll make more money selling my advice than following it" Steve Forbes, quoting his father, Malcom.
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