Bridge Crown

[Farrell]

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