Dale: I'm not picturing what you're trying to describe. "The rear foot of the gauge"? Both feet of the gauge sit on the "duplex" segment when you're measuring it, just as both feet of the gauge sit on the speaking length when making that measurement. Are you suggesting that the "front foot" when measuring the backscale is on the bridge and the rear foot is off--on the backscale string? This would an incorrect use of the tool, and fraught with error. After zeroing out the gauge on the bridge top (now that's a measurement that's fraught with error as well; if anyone assumes that the bridge top is all in the same plane, then there's a big mistake being made), the gauge is moved wholly to the front scale in front of the front bridge pin for a measurement and then wholly to the back scale behind the rear bridge pin for measurement, and the two combined yield a "net" bearing. Am I misunderstanding you? As dull-witted as I am, it wouldn't surprise me. Paul "If you want to know the truth, stop having opinions" (Chinese fortune cookie) In a message dated 05/03/07 23:21:58 Central Daylight Time, Erwinspiano writes: Yes Paul I believe this is right. I've always used Nick Gravagnes formula. The length of the backscale starting at the front bridge pin Times .026 = 1 1/2 degrees. i.e. a 4 inch rear length times .026 ==.104 thousands of distance bearing. The Only problem with all this extrapolation as I see it is that the rear foot of the lowell gauge sits behind the rear bridge pin, which is usually sitting lower than the actual elevation of the aliquout (or Whatever Del,Terry..grin). WHich means the gauge may actually read more bearing present than there is. Why? Hmmmm... Because of bridge slope to the rear & the grasp of the bridge pins. Of course the opposite could be true. Dale -------------- next part -------------- An HTML attachment was scrubbed... URL: https://www.moypiano.com/ptg/pianotech.php/attachments/20070504/404ea980/attachment.html
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