Correction, that should have read 7/32" shank. David Love davidlovepianos@earthlink.net > [Original Message] > From: David Love <davidlovepianos@earthlink.net> > To: Pianotech <pianotech@ptg.org> > Date: 5/12/2003 10:32:06 AM > Subject: RE: hammer mass (was Wurzen felt) > > Yes, it seems that it is not a pure test. It was interesting, however, to > observe the difference. It brings something else to mind, which is what > happens when, say, a new action with 7/16" shanks is combined with a hammer > weight from the original design which utilized 3/16" shanks and of a > different species of wood. My own experience does suggest that a light > hammer on a 3/16" maple shank does not sound the same as that same hammer > on a hex 7/16" shank made of hornbeam. > > David Love > davidlovepianos@earthlink.net > > > > [Original Message] > > From: Stephen Birkett <sbirkett@real.uwaterloo.ca> > > To: Pianotech <pianotech@ptg.org>; <davidlovepianos@earthlink.net> > > Date: 5/12/2003 9:18:36 AM > > Subject: hammer mass (was Wurzen felt) > > > > David Love scripsit: > > > I have had an experience on the other end fo the spectrum. I > > >have a customer with a Hamburg Steinway A (newer one). She wanted the > > >action heavier so a previous technician put clips on the shanks. Though > > >she liked the weight, the tone became very unpleasant to her and others > who > > >heard the piano. I suggested we try removing the clips (she had not made > > >the connection), fortunately an easy thing to do. The tone that she had > > >loved about the piano returned. A match of hammer weight to the > soundboard > > >assembly (and the relative density of the hammer, perhaps), is clearly > > >important. Heavier hammers do not always sound better, as I have often > > >heard stated here. > > > > An interesting experiment, for sure, but putting clips on the shanks > > is not the same thing as simply "increasing hammer mass". The clips > > will certainly affect the resonsant frequencies of the shanks which > > may well have been a significant contributor to the tonal change. We > > don't yet have general relationships which connect shank flexibility > > to tone, but there's plenty of anecdotal evidence about this, and > > shank resonances are a proposed mechanism. > > > > How to increase mass without altering shank resonance frequencies? > > You can't because *any* change in mass distribution of the > > hammer/shank system will influence these. Even adding or removing > > mass to (from) the hammer core may influence tone by altering the > > strike mass/string relationship, or by altering the shank/hammer > > resonances, or both. These are different phenomena. Unfortunately the > > nature of piano action mechanism makes it impossible to adjust > > independently only the strike mass/string mass relationship [which is > > what will be generally understood by "adjust the hammer mass"]. > > > > Ah...the complexities of our difficult friend the pianoforte. > > > > Stephen > > -- > > Dr Stephen Birkett > > Associate Professor > > Department of Systems Design Engineering > > University of Waterloo > > Waterloo, Ontario > > Canada N2L 3G1 > > > > Davis Building Room 2617 > > tel: 519-888-4567 Ext. 3792 > > PianoTech Lab Ext. 7115 > > mailto: sbirkett[at]real.uwaterloo.ca > > http://real.uwaterloo.ca/~sbirkett > > > > _______________________________________________ > pianotech list info: https://www.moypiano.com/resources/#archives
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