I'll throw my two cents in on this: I was taught that speaking length on C-88, on Steinways and most other pianos, should be right around 2" (plus or minus a bit, depending on whether it is a "hand-made/hand-fit" piano or not ;-) ). This corresponds to what I usually see when I am restringing pianos, whether they be Steinways, Masons, Baldwins, Chickerings, Knabes or what have you. Yes, it is often a little over or under this figure, but for me 2" seems a good point of departure. This corresponds with a pitch of about 4186 hz at C-88 (or tuning to A440). A couple of sixteenths of an inch over or under 2" doesn't seem to make a whole lot of difference, except in the percentage of breaking point/amount of tension the wire will be at when pulled up to pitch. If speaking length is significantly over 2", however,(like 2.5" in the present case) the wire is simply being asked to be stretched too tight to achieve the required pitch, and will break. Many of the pianos I have worked on that had string breakage problems in the high treble were found to have speaking lengths that were "too long", i.e. corresponding to very high or maximum percentage of breaking point when at pitch. Moving either the bridge or terminations so that the speaking length was shorter was really the only solution, if you wanted to be able to tune the piano to pitch. Significantly under length causes another problem. If the string speaking length is too short, breakage is not usually a problem, but the string simply may not sound very good, being at too low a tension. It doesn't matter what size wire you use, they will all break if the speaking length is excessive. A larger diameter wire simply requires more tension to be able to be pulled up to pitch, so any benefit in trying to use "thicker wire" is automatically cancelled out. This is a basic rule of piano string physics. If a size 12 1/2 wire breaks, a size 13, a size 14 and a size 16 will also break. It seems, however, technicians unaware of this simple rule of physics always have to go through the motions of trying a larger diameter wire, and still having it break, in order to learn this simple fact. (Go ahead, ask me how I know...) Like Ron N. said, it is the speaking length that is the problem here. After having rebuilt 100's of previously unrebuilt Steinways, from all periods, in our rebuilding shop, we learned that you simply cannot trust the factory workers to get the bridge placement right (or even close, in many instances)(or plate location as well, see below). You cannot assume that the factory workers "knew what they were doing," anymore than you should assume that subsequent rebuilders "knew what they were doing." In one original condition/unrebuilt Steinway "L" from the 70's we worked on, the back side of the top part of the treble bridge was actually up against the plate. Some of this, I think, may have had to do with the way they fit the pinblock to the plate flange at the factory at the time, which was done with the pinblock in the piano (i.e. already fitted to the stretcher and at the ends), -or at least, that was the way I observed them doing it when I went on the "factory tour" around 1990. The plate was lowered into the piano with graphite on the plate flange, and the worker placed go-bars between the plate and the "ceiling" to hold the plate down against the pinblock and inner rim ; the pinblock was then flexed up and down with a lever from underneath against the plate flange to transfer the graphite to the pinblock; the plate was then hoisted out; and then the high spots on the pinblock were ground down with an air grinder to fit. As I remember, all this was done without removing the pinblock from the rim. Evidently, in this process, it was possible to remove too much material from the plate flange edge of the pinblock in the process of mating it, which effectively moved the plate forward (i.e. closer to the stretcher) and increased the speaking length of the strings (since the soundboard and bridges were already fitted to the rim and in place as well). The plate location apparently depended on how far the worker ground down the pinblock in the mating operation. Not so much a problem in the mid range or the bass, apparently, but a few sixteenths of an inch off in the high treble, on those short strings, was critical. -Especially in this case, where the plate ended up rubbing against the back of the bridge. (I have pictures if anyone wants to see them...) This is an example of where a factory foul-up can make major problems for technicians down the line, and it happens all the time. As often as not, the piano is out of warranty by the time an alert technician finally discovers the problem, although in my book, major structural boo-boos of this sort should transcend normal warranty limitations. I always measure C-88 if there is ANY question, and if it is significantly more or less than 2", I start looking for bridge or plate placement problems. Yes, it certainly does appear that there is a lot of variation in the "standard piano of the world". The question is, why? I think part of the answer may lie in the fact that the pianos are indeed designed by scale designers and engineers, but they are not always around to check things when the piano is being made. Ken Bean PianoFinders -----Original Message----- From: A440A at aol.com [mailto:A440A at aol.com] Sent: Tuesday, October 07, 2008 6:39 AM To: pianotech at ptg.org Subject: Re: Unstringable C8, was Steinway 78183 Greetings, I have several of my pianos in the house right now. A model S, #333xxx. The C88 measures 2.25 inches! A model M, serial number 258xxx. C88 on it measures exactly 2 inches. An upright, model K # 78xxx C88 measures 1 15/16" A model A # 78861 measures 1 13/16 It appears that there is a lot of variation in the "standard piano of the world". The upright has the most responsive sound at C88. Maybe some of you scale/board gurus can shed some light on this? Regards, Ed Foote RPT http://www.uk-piano.org/edfoote/index.html www.uk-piano.org/edfoote/well_tempered_piano.html <BR><BR><BR>**************<BR>New MapQuest Local shows what's happening at your destination. Dining, Movies, Events, News & more. Try it out!<BR> (http://local.mapquest.com/?ncid=emlcntnew00000001)</HTML>
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