As an addendum to this, what makes more sense to me, if you are going to sort shanks, is to prepare the hammer set, weigh each hammer and alter the ones necessary so that the hammer weights themselves are a smooth progression. Then weigh the SW of each shank and sort them from heaviest to lightest. Then put the hammers and shanks together with the heaviest shank at #1 etc.. That way you will have a smooth total SW and the distributed SW relationship between shank and hammer would progress uniformly through the set. The resonance thing does complicate things though, doesn't it? David Love davidlovepianos at comcast.net www.davidlovepianos.com -----Original Message----- From: caut-bounces at ptg.org [mailto:caut-bounces at ptg.org] On Behalf Of David Love Sent: Tuesday, February 19, 2008 9:28 AM To: 'College and University Technicians' Subject: Re: [CAUT] Shank to Hammer weight spreadsheet I guess I haven't found that kind of variation in the shank weight (at least of similar diameter) to make it worth while to weigh and sort. I'm using pretty much exclusively Renner parts, maybe some others have more variation. The tapering does get a fairly even weight through the hammer set and after dry assembling and measuring SW's I'm rarely altering more than 1/3 of the set and usually the alterations are less than .3 grams. Mostly, I try to go up rather than down since once I'm through tapering the set, I prefer not to go back but if I do it's rarely for more than a couple of tenths and has no ill effects in terms of appearance. Are you suggesting that it may matter whether the SW distributional difference of even, say, .5 grams matters whether it's located in the shank versus the hammer in terms of inertia? Hard to imagine at that level that would really make any perceptible difference since some portion of that additional weight in the shank would have to be distributed out toward the hammer anyway, one would assume. If you wanted to get very picky about potential tonal differences it might be worth considering the variations in flexibility between shanks of equal diameter. Certainly rib flexibility (or stiffness) varies with ribs of the same dimension, why not shanks, I suppose. Maybe that's what the shank resonance thing speaks to-and perhaps the weight indirectly. At this point, I'm not convinced that other aspects of tonal variation (like soundboard resonances for example) so complicate teasing out that variable that it's worth the trouble. At a certain point, no matter what you do, voicing needs to be the last line of defense. The point at which each tech decides to put that into play, of course, will vary. David Love davidlovepianos at comcast.net www.davidlovepianos.com -----Original Message----- From: caut-bounces at ptg.org [mailto:caut-bounces at ptg.org] On Behalf Of Jon Page Sent: Tuesday, February 19, 2008 8:52 AM To: caut at ptg.org Subject: [CAUT] Shank to Hammer weight spreadsheet ...Once I'm done with that I simply dry assemble the shanks and hammers and then use the Stanwood scale to weigh the SWs. I chart those and then figure out where I have to alter them to achieve a smooth curve... I seems you are 'final fitting' your SW irrespective of the shank strike weight (SSW). If you initially taper your hammers to a close margin, then you are throwing the curve off with jumbled shanks and changing the mass of the hammer due to shank irregulatities. It would be more advantageous to match similiar SSW groups to your hammers which have been mass calibrated, thus reducing alteration. Ultimately, this is the most thorough method ineritally speaking. I simply mate the SSW with hammer weight to target a curve because does it really matter since it is at the end of the compound leverage system. Are you feeling hammer inertia or weight at the front of the key. Or what degree is it important (inertia at the end of the system) ans opposed to good inertial effect at the front of the key. -- Regards, Jon Page -------------- next part -------------- An HTML attachment was scrubbed... URL: https://www.moypiano.com/ptg/caut.php/attachments/20080219/53020b7a/attachment-0001.html
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