Mark, This discussion began with the hammer line being altered for better tone. I didn't make any adjustment for the weight change. No doubt there is a noticeable change in weight felt at the key. That'll have to wait for the next time I'm at the piano. Alan > From: Mark Cramer <cramer at brandonu.ca> > Reply-To: "College and University Technicians <caut at ptg.org>" <caut at ptg.org> > Date: Tue, 19 Feb 2008 16:57:04 -0600 > To: 'College and University Technicians' <caut at ptg.org> > Subject: Re: [CAUT] hammer line > > Hi Ric, > > I think what he means, is if you add 3mm (for instance) to the bore of > hammers at some point along your strike line, the bulk of the hammer's mass > (the big felt part) is now further from the pivot point. > > This has to affect MOI. As my good friend Stan Kroeker suggests, when you > move the weight up or down on an old metronome, it certainly seems to have a > measurable (predictable) effect on the speed. > > The same would be true for curving the line by moving hammers further/closer > to the center-pin. > > So, while I'm enjoying the exchange of good methods for measuring strike > weight, sorting, thinning shanks etc., I'm struggling with the concept of > sorting shanks over .1 gram difference, distributed who-knows-where along > it's length, but moving a 4-10g hammer in/out by several mm and not > accounting for it. (!?) > > If I've missed this in the discussion, please (anyone) feel free to "tune me > in," either on, or off-list. > > I'm in favor of the pursuit, but just need to know that we are aware of and > dealing with "all" the variables. > > BTW Ric, thanks for the spreadsheet, it's a good working tool! > > Best regards, > Mark Cramer, > Brandon University > > > > -----Original Message----- > From: caut-bounces at ptg.org [mailto:caut-bounces at ptg.org] On Behalf Of > Richard Brekne > Sent: February 15, 2008 3:25 PM > To: caut at ptg.org > Subject: [CAUT] hammer line11 > > > Now this is an interesting concept. How does altering the bore length > to match string height variances move the mass farther out on the arc... > and how does this in turn add up to a more serious problem then the at > least two biggies I can see it corrects ? > > Cheers > RicB > > > So, if the strike line you set "by-ear" ends up being a little > crooked, and > uneven string height is the culprit, why not vary the bore-length? > > > A wise and valued supplier who I turn to for pre-hungs when things get > "bizzy," will not do this for me. His claim being that moving mass > further > in/out on the arc will have more detriment than anything I'm trying to > correct. > > > >
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