Vladan writes: << I think the most important factor is the rotational moment of inertia of the key stick. This is largely determined by the amount of lead and the position of the lead in the key. For fast return, you want less lead, and the lead should be as close as possible to the fulcrum point (balance pin).<< The lightest key in the world will not return very fast if the capstan is too close to the balance pin. >>In order to achieve that, and still maintain the proper static balance weight, the action needs to have a low ratio geometry.<< Is this to say that the high ratio actions will not repeat as fast? My experience is otherwise. >>The other factor influencing return speed is the strength of the wippen spring. This adjustment, like all others, is a compromise too. A stiff spring setting will help return the key faster.<< I have not found this to be so. All other things being equal( and within bounds), there is virtually no measurable difference in repetition speed between a spring that throws the hammer off the jack when released from check and one that simply lifts the hammer just slowly enough that it can't be felt. However, the former makes escapement a clumsy chore for pp playing. I still maintain that the major determinate in repetition speed is the height of check. 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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