No! It makes no sense! I leave it to you to build a bridge that is kerfed on the underside, bent to fit the board and then filled with epoxy! Thump! --- Farrell <mfarrel2@tampabay.rr.com> wrote: > I've done some playin' and some tinkin'. And I've > decided that there is a difference between a crowned > bridge, but that the difference, in practical terms, > is negligent. > > If you cut a circle out of cardboard one foot in > diameter, and then cut a circle out of the middle of > that, let's say eight inches in diameter, you have a > big flat donut. Set that donut on a basketball so > that it sets like a topless hat. Now also realize > that you need about a foot of tangent coming off the > donut at some point (low tenor or long bridge). Now > you can see the argument for a crowned bridge. Or > perhaps not really just a crowned bridge, but a > bridge that has a bottom bevel in the treble area > and a crown in the lower tenor. > > Now back to reality. Soundboards, even Fandrich > soundboards, have a larger crown radius than a > basketball, and a bridge is only 32 or 35 mm wide. > So I do suppose that the ribbed soundboard panel and > bridge itself will conform quite readily to the very > slightly mis-matched straight bridge and curved > soundboard panel. The tenor end will bend enough > (what, maybe 1 mm) and the treble section of the > bridge can have a top whose plane is not quite > parallel to the plane of the bridge bottom/panel top > interface. Bottom line: any difference is close to > or wholly within common woodworking error and > completely negated by the flexibility of the woods. > > That make sense? > > Terry Farrell > > ----- Original Message ----- > From: "Ron Nossaman" <RNossaman@cox.net> > To: "Pianotech" <pianotech@ptg.org> > Sent: Sunday, April 13, 2003 12:02 AM > Subject: Re: Killer Octave Question > > > > > > >FWIW: I just cut a long bridge out of an old > Mason & Hamlin and it is as > > >flat as a pancake. Not a speck of crown to be > found. > > > > > >Terry Farrell > > > > You can tell? How tragic. One of the points I try > to illustrate in my > > bridge building class is the difficulty in > determining whether or not the > > original bridge was crowned, and how important it > is to the assembly. An > > old Knabe bridge, lying on a table and propped up > in the middle with a > > pencil, shows a lovely crown from end to end. Pull > the pencil out, and it's > > dead flat. That bridge will lay on a crowned > soundboard and very nicely > > conform to the crown of the board. > > > > Ron N > > > > _______________________________________________ > > pianotech list info: > https://www.moypiano.com/resources/#archives > _______________________________________________ > pianotech list info: https://www.moypiano.com/resources/#archives __________________________________________________ Do you Yahoo!? Yahoo! Tax Center - File online, calculators, forms, and more http://tax.yahoo.com
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