Jon, Thanks for the offer on the wall sculpture, ah, I mean piano. I even have a corner of my "shop" (garage) to put it! :-) Seriously (or maybe you were) What I was after was a soundboard outline to continue the string model. At this point, I'm just following an idea and don't want to take the time to measure. If the results look like something I believe or come up with an idea on an improvement, I'll model parts from a real piano that I could take measurements from, create a FEA model, make 'theoretical' improvements on the piano, then check out the 'real' improvements. Before I spend too much money, I thought I'd take the time to go through a complete analysis to find out how much effort it takes and if any new modeling ideas come up that I'd really want to test on a real piano. doug richards San Jose, CA > -----Original Message----- > From: Jon Page [SMTP:jpage@capecod.net] > Sent: Saturday, August 29, 1998 5:28 AM > To: pianotech@ptg.org > Subject: RE: Single Treble Bridge > > Doug, > I have just the item for you. > A Rippen back w/ Aluminium plate, board/bridges, strung. 40"h > > Having given the fold-down action/keyboard to Debbie Legg, > the back NEEDS a place to go. PERFECT for the your project. > > Only thing, it's here on the East Coast. I can prep it for shipping > and get it to the freight dock, (we'll pass the plate for shipping > for everyone to reap the benefits of your samplings. :-) > It's a light-wieght compared to most, this piano was designed > to be portable hence the fold-down keyboard. > Full perimiter plate, no back posts, just plate, board, strings. > The block is segmented like the Yamaha elec. grands. > > I can pack it up this week and send it on it's way since I have to go to > that same freight dock to pickup a piano coming in for refinishing. > > I can call for a rough price on shipping on Monday. > > Don't miss this opportunity to gain a valuable testing device > and clear-up a corner of my shop ! > > Anxiously awaiting your reply, > > Jon Page > Harwich Port, Cape Cod, Mass. (jpage@capecod.net) > > PS Makes a nice wall sculpture too. > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > At 12:52 PM 8/28/98 -0700, you wrote: > >Del, > > > >You wouldn't happen to have an outline of a medium sized sound board and > >bridge in electronic format would you? > >Don't know if you saw my post yesterday, but I'm doing some modeling on > >string inharmonicity. Some time in the future, I'll be wanting to add a > >soundboard with bridge and look at string tail length/angle, soundboard > mode > >shapes and stuff like that. > >Anyway, if you have a file available (dwg, mi or dxf) it sure would save > me > >a bunch time measuring... > > > >doug richards > >San Jose, CA > > > >> -----Original Message----- > >> From: Delwin D Fandrich [SMTP:pianobuilders@olynet.com] > >> Sent: Friday, August 28, 1998 10:47 AM > >> To: pianotech@ptg.org > >> Subject: Re: Single Treble Bridge > >> > >> > >> > >> Tom Cole wrote: > >> > >> > Del, > >> > > >> > You discussed, in a recent post, the need for a separate tenor bridge > >> > for wound strings and that the speaking lengths should be an > extension > >> > of the bass section. It occurred to me today that Steinway tried that > >> > over 100 years ago and abandoned the idea. I also have heard of > someone > >> > who has converted the early model As to a single treble bridge > design, > >> > saying that it's an improvement. > >> > > >> > So I'm confused and would like to hear your opinions on this > conundrum. > >> > > >> > Tom > >> > >> -------------------------------------------------- > >> > >> Tom, > >> > >> Over the years Steinway has abandoned a lot of good design ideas while > >> clinging > >> tenaciously to a few bad ones. Obviously, Steinway builds some > excellent > >> pianos, but they are certainly not the last word in piano design. Nor > am > >> I. > >> Nor is anyone else that I know of. So, with that in mind... > >> > >> Not all of the ideas that were tried out and abandoned 100 years ago -- > >> whether > >> by Steinway or by anyone else -- were bad ideas. Sometimes ideas came > >> along > >> before their time and had to wait for appropriate materials to come > along. > >> Sometimes manufacturing technology was not developed adequately to take > >> full > >> advantage of an idea. Other times a good idea was simply executed > poorly. > >> This > >> was the case with the short bridge on the three-bridge Model A. I'm > >> assuming > >> this is the piano you're referring to in your post. > >> > >> There were three problems with this specific design: > >> 1) The string lengths in the short bridge section were too short. > I > >> assume > >> this was done so that tri-chord wrapped strings could be used. This, > of > >> course, > >> was the second problem. > >> 2) Tri-chord wrapped strings were used. I have yet to see a scale > >> using > >> tri-chord wrapped strings that I really liked. > >> 3) The soundboard and ribs did not acoustically tie the three > >> separate > >> sections together. In part this was a consequence of the > >> compression-crowned > >> soundboard design. It is very difficult -- nearly impossible -- to > alter > >> the > >> elasticity characteristics of a compression-crowned soundboard to > >> adequately > >> blend the several disparate sections of the scale together. > >> > >> There are some real problems trying to redesign things like this on an > >> existing > >> piano. I am also interested in loudspeaker design. The bass/tenor > >> transition > >> of the piano scale is much like the crossover design between a woofer > and > >> a > >> mid-range speaker -- fairly simple in concept, much more difficult in > >> actual > >> practice. We struggle with these issues every day since nearly every > >> piano that > >> comes to our shop is sent here for some level of redesign along with > its > >> remanufacture. We are limited by the original string scale layout -- > >> i.e., > >> action center spacing and their sweep -- and the original configuration > of > >> the > >> plate. > >> > >> In the case of the three-bridge Model A, the compass of the bass > section > >> should > >> have been much greater. In a piano of this size the bass section > should > >> encompass at least 27 notes (instead of 20). The short tri-chord steel > >> strings > >> often found at the low end of the tenor bridge have a tubby tone that > >> simply > >> cannot be voiced out with hammer work. Even then there should have > been a > >> few > >> unisons of wrapped bi-chords terminated on a separate bridge on the > tenor > >> side > >> of the bass/tenor plate break. Done properly, this short bridge could > -- > >> and > >> probably should -- have been tied into the long tenor bridge. > >> > >> I have also worked with the idea of a single treble bridge on these > >> scales, but > >> I'd not go so far as to call them much of an improvement. They were, > >> perhaps, > >> less bad. The real improvement comes with a new short bridge using > >> properly > >> scaled bi-chord wrapped strings. Along with a soundboard and rib > system > >> designed to bring the three separate sections -- the low end of the > long > >> tenor > >> bridge, the short cross-over bridge and the high end of the bass bridge > -- > >> together. Even then, there remains a serious discontinuity between the > >> lengths > >> of the low tenor strings and the upper bass strings that cannot be > >> corrected > >> without building a new plate. > >> > >> It is really much easier to start with a clean computer screen and > design > >> the > >> thing from scratch. When doing this all of the various factors can be > >> balanced > >> out much more easily. Much has been learned about piano design in the > >> past 100 > >> years. It's just that little of this knowledge has been incorporated > into > >> the > >> pianos of today. > >> > >> Rather than answer your question, I've probably just posed a bunch of > new > >> ones. > >> Such is life. Isn't it wonderful? > >> > >> Regards, > >> > >> Del > >> > >> "If it ain't broke -- break it. Then build it better." > > > >
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