I'm not sure what a "scratch" test is. I can tell if the shanks have been thinned. I usually can tell during the initial voicing if the shanks have been sequenced by pitch. I'm not sure how long Chris has been sequencing shanks by pitch but I have been doing it for at least twenty years. Dave, my brother's 6'4" Knabe has the shanks pitch sequenced. Remember that piano? I explained how to sequence them in a previous post. It isn't that hard to use one shank to compare against other shanks that have had material removed. The only area I care to remove material is from the sides because it also affects the lower harmonics created when the hammer hits the strings. I am aware of two things that happen when the shank is thinned on the sides: the shank "doink" sound goes up in pitch and the lower harmonics on that particular note become stronger. Tim Coates On Feb 22, 2008, at 10:36 AM, Porritt, David wrote: > I'm not being contrary but when you walk up to a piano and play it can > you tell a difference if the person who hung the hammers didn't > tune the > shanks? > > Sincere question. > > dp > > David M. Porritt, RPT > dporritt at smu.edu > > -----Original Message----- > From: caut-bounces at ptg.org [mailto:caut-bounces at ptg.org] On Behalf Of > Chris Solliday > Sent: Friday, February 22, 2008 9:55 AM > To: College and University Technicians > Subject: Re: [CAUT] Shank Pitch > > maybe what they are doing at the Bluthner factory is different from > what > I > do but when I remove material the pitch goes up in my scratch test. > Perhaps > this is not the best test. > Chris Solliday > ----- Original Message ----- > From: "Ron Nossaman" <rnossaman at cox.net> > To: "College and University Technicians" <caut at ptg.org> > Sent: Friday, February 22, 2008 10:25 AM > Subject: Re: [CAUT] Shank Pitch > > >> >>> Chris & all >>> >>> I do know that to lower the pitch on a reed organ reed you scrape >>> material from the bass end of the reed making the mass of the end of > the >>> tongue heavier in relation to the overall reed and the pitch goes > down. >>> I have never tried it on a hammer shank but I can see where the same >>> principle would apply. >>> >>> Norman Cantrell >> >> Hi Norman, >> In the organ reed, scraping the tip of the reed removes mass, >> raising pitch. Scraping the base end of the reed decreases >> stiffness, lowering pitch. >> >> Resonant frequency in anything is determined by a combination >> of stiffness and mass. In the case of hammer shanks, it would >> appear from the reported results that the loss of mass >> realized in thinning has a greater affect on "doink" pitch >> than the loss of stiffness. >> >> I don't tune shanks, so I wasn't aware of this. I would have >> expected the shank pitch to drop. Interesting. >> Ron N > >
This PTG archive page provided courtesy of Moy Piano Service, LLC