David, I also always feel a particularity in the touch when assist springs are used. There is some kind of "assistance " given that the pianist have to anticipate when playing. I did not have the opportunity to test with screw regulatables springs, only using the weight off and a dynamometer to even and regulate them - not really an easy thing, and probably not very stable, considering the design of the usual rep springs with their short arm, and the way they are regulated , installing a kink or bending the arm, while the coils stay the same. A good method to recently address the coils should be of some interest (I know, screws !) Using them in conjunction with linked whippen/key make sense, but this arrangement is prone to rebound too easily. Greetings. Isaac OLEG Isaac OLEG Entretien et reparation de pianos. PianoTech 17 rue de Choisy 94400 VITRY sur SEINE FRANCE tel : 033 01 47 18 06 98 fax : 033 01 47 18 06 90 cell: 06 60 42 58 77 > -----Message d'origine----- > De : pianotech-bounces@ptg.org > [mailto:pianotech-bounces@ptg.org]De la > part de David Love > Envoye : samedi 14 juin 2003 17:24 > A : Pianotech > Objet : Re: Key Leads and Inertia > > > I can't comment from real scientific data, but I have never > liked the feel > of assist springs when they are tensioned above some > undetermined amount > (say, 10 - 15 grams which is typically the level at which > they are used), > if at all. I am suspicious of the disconnect that they > create between key > and wippen with the assist spring always pushing the wippen > away from the > key. Any bounce in the hammer off the rest rail (something > that they also > contribute to) will enhance this disconnect. My hypothesis > is that an > assist spring will work best when used in conjunction with > a rocker arm > capstan arrangement in which the key is directly linked to > the wippen. > With an adjustable rep spring, you could easily adjust the > degree of assist > by measuring the change in downweight as you tighten the spring. > > David Love > davidlovepianos@earthlink.net > > > > [Original Message] > > From: Bill Ballard <yardbird@vermontel.net> > > To: Pianotech <pianotech@ptg.org> > > Date: 6/14/2003 5:21:01 AM > > Subject: Re: Key Leads and Inertia > > > > We are both paraphrasing the whispers from the great > unwashed. Can > > someone on the list comment on the performance shortcomings of > > springs? Are these shortcomings a direct function of the > amount of > > work the springs are doing? > > > > > > _______________________________________________ > pianotech list info: https://www.moypiano.com/resources/#archives >
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