Clyde, David Stanwood has written articles in the Piano Technicians Journals that explain this metrology for measuring touchweight. If you have access to back issues of the Journal look these up and read, and reread and reread... Also, you might get a little additional info by searching the archives of this list. Look for postings by keywords such as Stanwood, touchweight, strike weight and balance weight. The guild will sometimes have classes taught by David Stanwood at the convention. It seems to be time for this to be offered again. Bob Hull --- Clyde Allen <tunepiano1@yahoo.com> wrote: > Hello Bob, > Where can I find definitions and how to measure > these various quantities you folks are discussing. > It sounds very interesting but I am in the dark! SW, > DW, UW, FrontW, WBW etc... etc... etc... Thanks for > your reply. > > Clyde Allen > Silver Spring, MD > > > Bob Hull <hullfam5@yahoo.com> wrote: > Hi Richard, > > Thanks for your reply. > > you wrote: Stanwood suggests given SW curves for > > each Ratio and BW... > > tho you dont see that on most of the Smart Charts > > published. > > > > If you give us some more specifics, perhaps we can > > offer better advice. > > Where are these sw curves suggested in correlation > to > particular ratios and BWs ? You referred to a number > 10 curve. I'll give some more details here about > this > action. This is with the new hammers. > > N SW D U BW FrontW R WBWAvg. > ___________________________________________________ > 1 12.1 56 27 41.5 37.5 5.7 9 > 2 11.6 56 27 41.5 32.9 5.6 9 > 9 11.5 50 23 36.5 39.0 5.78 etc. > 10 11.7 53 28 40.5 32.6 5.4 > 16 11.4 48 20 34 40.8 5.7 > 17 11.1 48 21 34.5 37.1 5.6 > 28 10.8 48 25 36.5 32.1 5.5 > 29 10.4 44 19 31.5 35.2 5.5 > 40 9.7 31.6 > *(40 10.8 48 26 37 31.6 5.5) > 41 9.6 40 17 28.5 33.1 5.4 > 52 9.5 44 22 33 29.2 5.6 > 53 9.3 46 21 33.5 27.2 5.5 > 64 8.3 46 27 36.5 20.3 5.7 > 65 8.2 44 26 35 19.3 5.5 > 87 6.6 49 29 39 6.8 5.5 > 88 6.4 50 34 42 3.5 5.7 > > (*C40 had 1.1 g temporarily added to the hammer) > > Do I understand that BW should be fairly constant > across the keyboard while SW, Frontweight and > downweight are going to smoothly decrease? Although, > downweight may just decrease from 52 to 48. > > Also, for good tonal projection is a sw of 12 > enough? > > I hope this info will help you advise me if you > don't > mind. Thank you. > > Bob > > > > > Hi Bob > > > > You dont really leave us much to go on here to > offer > > any real advice. > > One of the great assets of Stanwoods method is the > > whole slew of terms > > and definitions that allow us to easily converse > > about and understand > > any given touchweight situation. You mention a 5.5 > > ratio as an optimal, > > and that you are having problems dealing with > > appropriate Frontweights > > for a given Strikeweight curve.. without > mentioning > > what that curve is. > > > > To begin with... A 5.5 ratio will yield a number > 10 > > (if I remember > > right) curve assuming a 9.0 whippen radius weight > > and a 38 gram BW. > > This will also yeild the maximum Front weights > > published in the Stanwood > > kit. > > > > From that perspective... it doesnt really matter > > which you do first.. > > All that matters is that you do your diagnostics > > right and arrive at the > > correct Balance Weight Ratio... (SWR). > > > > > > The point is... when you know your Ratio, have > > decided upon your desired > > BW... the rest is more or less given. You can > > juggle SW curves if you > > want... but > > > > Cheers > > RicB > > > > > > Bob Hull wrote: > > > > >These are questions about component touchweight > > >balancing with the SmartChartTM. > > > > > >I have put new hammers on an action and I'm > working > > on > > >getting the strike weight smoothed. There are a > > good > > >many keys that exceed the front weight ceiling. > The > > >leading doesn't "look" excessive like some > leading > > >I've seen before. > > > > > >A strike weight ratio of 5.5 is what I understand > > to > > >be best for this piano. > > > > > > > > why... specifically ? > > > > >Should the front weight issue be adressed first > > even > > >if it has to be adjusted again? The strike > weights > > >will need to be adjusted mostly upwards. > > > > > >I'll appreciate your comments. > > > > > >Bob > > > > > > __________________________________________________ > Do You Yahoo!? > Tired of spam? Yahoo! Mail has the best spam > protection around > http://mail.yahoo.com > _______________________________________________ > pianotech list info: > https://www.moypiano.com/resources/#archives > > __________________________________________________ > Do You Yahoo!? > Tired of spam? Yahoo! Mail has the best spam > protection around > http://mail.yahoo.com __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com
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