---------------------- multipart/alternative attachment Ric and list, The downbearing calculations shouldn't be too terrible. The triangle idea is on the right track. It is called vector summation. The hypotenuse of the right-triangle is the string tension. The small side is the downbearin= g force (assuming small downbearing angle). The angle used should be the angle between the speaking length of the string and the backscale length. Example: Downbearing angle =3D 2 degrees, string tension =3D 160 pounds: String Tension x Sin(downbearing angle) =3D Downbearing Force i.e. 160 x Sin(2 degrees) =3D 5.58 pounds (3.49% of string tension) This would be real simple to add to a spreadsheet like the one Ron Overs posted on Jan. 21st. Also, be careful with spreadsheet calculations in EXCEL. My version uses angular units in "radians" not "degrees". 180 degrees are equal to "pi" radians (pi =3D ~3.1416), so one radian =3D ~57.3 degrees. The formula abo= ve in EXCEL could be "=3D160*sin(2/57.3)". This advice has nothing to do with how much downbearing is desirable, only how it could be calculated. Having just said that, it appears that if the desired total downbearing is only in the ballpark of 0.5% to 1.0% of total string tension, then the average downbearing angle would be in the range of 0.29 to 0.57 degrees. Hmm... Have fun! Best Regards, Steve Fujan www.fujanproducts.com On 2/19/06, Ric Brekne < ricbrek@broadpark.no> wrote: > > Please correct if this is entirely wrong... but I thought that since the > string was being measured in terms of its tension (pounds) one could > simply the problem as a like sided triangle with half the pounds on > each leg. Since the measurement is taken in the deflected condition... > you have basically the hypotenus and all angels of a right angle > triangle available to figure the amound of deflection.. pounds in this > case. So 160 pounds with a 2 degree deflection at the bridge yields > > Sin 1 x 80 =3D 1.396192515 lbs downbearing, which is 1.745 % of the > string tension. > > er... yes ?? > > RicB > > > ------------- > > So knowing all of the above, what is the equation that will calculate > > an approximate string bearing load under the conditions I describe? > > Beats me. I use the SIN(RADIANS(degree measurement))*tension > per unison, and add them up in my spreadsheet. > _______________________________________________ > Pianotech list info: https://www.moypiano.com/resources/#archives > ---------------------- multipart/alternative attachment An HTML attachment was scrubbed... URL: https://www.moypiano.com/ptg/pianotech.php/attachments/44/d5/99/7f/attachment.htm ---------------------- multipart/alternative attachment--
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