I have also seen laminated ribs on older pianos. So far, however, they have all been quite different from those I use. I have seen vertically laminated ribs and flat horizontally laminated ribs but never horizontally laminated ribs in which the crown is molded in as the rib is laminated. But -- there may well be some out there I have not yet encountered. When I started experimenting with, and then using, laminated ribs some three decades back there were no pianos using them on the market that I am aware of. Nor are there now. Other than in a few rebuilding/remanufacturing shops. ddf | -----Original Message----- | From: pianotech-bounces at ptg.org | [mailto:pianotech-bounces at ptg.org] On Behalf Of Euphonious Thumpe | Sent: January 28, 2009 8:43 PM | To: pianotech at ptg.org | Subject: Re: [pianotech] FW: laminated ribs again | | Not at all meaning to "pick on you", Del, but my 1899 Knabe | has laminated ribs. I doubt they're anywhere nearly as | scientifically designed as yours, but it's nice to know | someone also "came up" with this idea, "way back when". Has | anyone here pursued laminating ribs on old soundboards "in | situ" to improve lost crown? ( With a thin strip added to the | spine of the old rib, in a compressed caul? ) I'm considering | experimenting with this method, on a really crummy old | upright, strings in place, with a collapsed board. | | Euphonious Thumpe | | | > I've probably been using laminated ribs longer than anyone | else in the | > business. | > One of the reasons I became interested in laminated ribs was the | > inconsistency of ribs cut from solid stock. Both the mass and | > stiffness of conventional ribs varies widely depending on | the physical | > characteristics of the wood from which they are cut. By building up | > the ribs using thin strips of wood of varying grain characteristics | > both the mass and stiffness of the laminated ribs tends to be more | > predictable and consistent. | > | > | > | > Back when I was experimenting with the process I did do | some testing | > to establish a basis on which I could calculate rib stiffness. | > The primary impetus | > for developing laminated rib technology was to be able to | predict the | > acoustical performance of a rib-crowned soundboard system | so I needed | > to know how they would react under load. I would suggest anyone | > switching to laminated ribs do the same. I've always | thought it a good | > idea to have a thorough personal understanding of the systems and | > materials with which I work. | > | > | > | > Yes, I do follow a criteria for scalloping ribs. The description of | > what I do and the explanation of why I do it is rather more | involved | > than I care to go into on this list but it is something I cover in | > several of my all-day seminars. | > Others probably do as well. You might check the line up of classes | > being offered at the Annual PTG Convention this year. I don't know | > just what is being offered but there might well be | something on this | > topic. | > | > | > | > ddf | | | | |
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