>When building a new bridge, my understanding is that you will want to put a >concave curve along the long axis of the bridge bottom (or maybe you will >even want to modify an old bridge that does not seem to have the proper >bottom curve). But how much curve? I strongly suspect no approach to this >will be perfect, but we presumably should have some target in mind. Do we >clamp the soundboard into the piano (or install it), let it equilibrate with >the shop environment (letting it achieve its normal crown), and then attempt >to put the same crown as the soundboard has inversely on the bottom of the >bridge? Or do we want to guess at how much the board will compress under >string load and target that curve/crown? Or do we want to approach it in >some other manner? Or just put a 60-foot radius on the bridge bottom and get >some sleep? > >Ideas? Thoughts? Sarcastic criticisms? > >Terry Farrell Flat. Works fine. We did this on the list just a couple of months ago. The bridge is curved. A crowned bridge will lay flat on a crowned soundboard. A flat bridge will also lay flat on a crowned soundboard. A crowned bridge will neither conform to the board better, nor support any more bearing by virtue of it's crown. Having done them both ways, I can't detect any benefit at all to crowned bridges unless you're charging by the hour. Nearly as I can tell, the curve makes bridge crowning superfluous. Ron N
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