Richard Brekne wrote: > Yes... thats true enough. But one thing at a time as it were. It seems > reasonable to first figure the velocity of the hammer for key velocity > as if it were in total compliance, then figure a compliance value, then > find that combination of inertia, mass, leverage, whathaveyou that sees > the maximum amount of hammer velocity for key velocity coincide best > with the saturation point of the action. Yes ? Richard, Your right about the primacy of finding the relationship between acceleration, velocity and inertia in the action. Especially if one wants to graduate from the simple problems of action statics, that only address the action at rest, to the difficult but more promising study of the action in motion. In fact there is no other way to study the forces that develop in the action except by finding the MOI first. It stands to reason that without knowing the forces you can't begin to understand the various reactions such as bending and compression that rob the action of power. For example, it is not enough to simply know the force applied at the key to figure out how much force is applied to bend the key. Let's say you drop a weight on the key of an action from a certain height. The force bending the key can not be know from this information alone. If the same weight is dropped on the note with little MOI in the action chain the key will bend less than if it were dropped on a note with large amounts. The forces available to bend the key are directly proportional to the MOI of the action chain. John Hartman RPT John Hartman Pianos [link redacted at request of site owner - Jul 25, 2015] Rebuilding Steinway and Mason & Hamlin Grand Pianos Since 1979 Piano Technicians Journal Journal Illustrator/Contributing Editor [link redacted at request of site owner - Jul 25, 2015]
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