pianorye@yahoo.com writes: << Less friction means more power, lighter touch, faster repetition. >> Greetings, I must respectfully question two out of three of these. Of course, less friction will produce a "lighter touch", but of the other two, consider: the speed of repetition is governed by the distance the hammer is held from the string when in check, and the return speed of the key when released. It will be observed that in fast repetition, upon release of the key in preparation of the next blow, the hammer does not rise from its checking height until the jack returns under the knuckle and the key is once again depressed. (We check spring strength by watching the hammer rise from check, but in fast play, the hammer doesn't move upwards until the key propels it.) It follows that the less hammer flange friction there is, the weaker the rep. spring will be, and the slower the acceleration of the key. The leverage and inertia found in the key is so great that the return speed varies very little with spring strength. In practise, there is virtually no difference in key return speed between a spring that slams the hammer upwards and a spring that lifts it gently. All the excessive spring strength does is to make escapement unnecessarily difficult. As to "power", we "Jolly" well know that there is a loss of power and tone when the hammer flange is too loose, so I suggest that power will suffer with looser pinning, (up to a point). The tighter pinning is of major effect on softer playing, since under a very hard blow, the felt in the bushing is distorted enough so that only one side of the bushing is really in firm contact,(on a hammer flange, it is the upper part of the bushing that is taking the load). When the bushing is thus distorted, its friction from the circular compression that we see in static testing is greatly reduced. Regards, Ed Foote RPT http://www.uk-piano.org/edfoote/index.html www.uk-piano.org/edfoote/well_tempered_piano.html
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