Vince Myrako wrote: > .... One thing that would be interesting from this type > of study would be to find out the optimal weight of a hammer for a > particular size and tension of string. > This is one of the main threads in my new project. If you look at pianos from 18th to 20th C. everyone is familiar with the general trend of increased string diameters...increased hammer mass...heavier actions. But exactly how this empirical relationship is determined still seems to not be understood. By extension such results sill apply to variations on the modern piano. If you match a Stein (c1780) action with a stringband scaled like an 1815 Streicher (as in one modern `copy' I recently came across...or a heavier c1800 Walter action with a thin-stringed Stein scaling (as is common with many modern `improved' fortepianos), you get wierd tonal results that have nothing in common with early pianos. I don't think there is an `optimal' relationship between hammer and string mass in terms of tonal properties...this will be subjective. Even strictly in terms of efficiency of energy transfer other factors such as shank or hammer head compliance will enter into the problem. That is surely why similar tonal effects can be achieved by techs filing either the heads (reducing mass) or thinning the shanks (increasing compliance), but the results will also have tonal differences. Efficiency of energy transfer is less (speaking from memory here...will check) in the bass, with mutiple hammer/string contacts, than with lighter hammers. That is the percent transfer of hammer kinetic energy to the string....as Vince notes, the total energy transferred will obviously depend in absolute terms on the mass and velocity of the hammerhead. BTW *efficiency* of energy transfer also depends quite noticeably on the the velocity...therefore there will be a difference between loud and soft blows. Stephen Birkett (Fortepianos) Authentic Reproductions of 18th and 19th Century Pianos Waterloo, Ontario, Canada tel: 519-885-2228 fax: 519-763-4686
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