>Hmmmm. I agree three measurements will give you more info, but I should >think with the two you could conclude positive or negative bearing. Right, but not necessarily positive front bearing. >- when the piano was new, presumably both >the front and rear string segments were angled upward toward the bridge.) Hopefully, but again, not necessarily. >The instructions say to multiply these number buy 0.003 to get an answer in >thousandths. Mr. Lowell sure made a neat little gauge, but it does not seen >that he was a scientist. Thousandths of what? Inches? Degrees? It must be >degrees? That's 0.003" per inch, I believe, or 1/6° per line. That's why I like measurements stated in degrees, so it will mean the same thing to everyone everywhere - except maybe Elbonia. >I can see how this bridge is apparently rolled toward the piano rear in the >tenor, and overall bearing is negative in this area. Again, not necessarily. The back scale is considerably shorter than the speaking length, so the back angle changes much more for a given bridge height change than does the front angle. Assuming the bridge went straight down without any "roll" whatsoever, taking the speaking length and "duplex" length of say, F5 or C6, at what bridge top height above string plane would there be a positive back angle? What's the resulting front angle, and the difference in bridge heights between this computed one and what's there in the piano now? I seriously doubt that it's physically possible for a solid bridge to "roll" backward here. >However, it still seems to me that these numbers on a flat board mean this >board is toast. Opinions? > >Terry Farrell Agreed. Ron N
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