Terry: The conversion from the mils measurement (thousandths of an inch) to a tangent value is straightforward. If I recall correctly, 3 units to the positive bearing from both sides of the bridge (net) yields 6 x 0.003"=0.018 which is the tangent of 1 degree net bearing over the bridge. Hmmm, maybe I have to look up my tangent tables to be sure of this, but I think it's right. 0.026 is the tangent of 1 1/2 degrees, I think. Anyway, that's the conversion. And someone should make that clear with the instructions, you're right. Paul "If you want to know the truth, stop having opinions" (Chinese fortune cookie) In a message dated 05/03/07 17:00:47 Central Daylight Time, mfarrel2 at tampabay.rr.com writes: Breaking news item: Lowell Component Downbearing Gauges are now available from Pianotek. I have a question regarding the instructions for measuring downbearing: "Multiply the number of divisions the bubble crossed by three and one has the front or rear bearing, in thousandths." My high school chemistry teacher would string the author of this gibberish up by his/her thumbs. I can hear him now: "Where are your units? Without units this means nothing!" Thousandths of what? Inches I suppose. But what does that mean? So I have a couple thousandths of an inch of downbearing - what does that tell me? I don't have a backscale length. The only thing that means anything is an angle. Angles are not measured in thousandths of an inch - it is not a linear measurement. Are they trying to suggest a slope maybe - as in so-many thousandths of an inch of vertical length per inch of horizontal length? The author should get a job at NASA and send another rocket crashing into Mars..... ;-) Terry Farrell Farrell Piano PS: Units - a little pet peeve of mine! www.farrellpiano.com terry at farrellpiano.com -------------- next part -------------- An HTML attachment was scrubbed... URL: https://www.moypiano.com/ptg/pianotech.php/attachments/20070503/44189103/attachment.html
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