Del, oddly enough I tuned an identical piano today. It was the same make and there was a difference of less than 1000 between the serial #'s. The scales and plate markings were the same. This other piano had already been restrung. The bass strings were not like the original set I removed from my piano, my piano having 12 double wrapped strings the other piano having only 8 double wrapped string. I took the opportunity to measure those strings. Would you believe that A0 had a core of .055" and the O/A diameter was .292". The lowest single wrap string (E1) had a core of .051 and an O/A of .200. Actually, A0 didn't sound bad at all... given the small size of the piano. John Gunderson, North Jersey Chapter Delwin D Fandrich wrote: > ----- Original Message ----- > From: John Gunderson <jgunderson@monmouth.com> > To: <pianotech@ptg.org> > Sent: Wednesday, August 04, 1999 5:55 AM > Subject: bass string design > > > Thanks to all for the input. I think that Del Fandrich provided the > answer I > > was looking for, that being that there is an optimum proportion of core > > diameter to o/a diameter. Thinking about it, it make sense that as you > bend a > > wrapping around a core you are stressing the outter fibers of the > wrapping. The > > tighter the bend, the greater the stress. Eventually a point is reached > where > > the fiber structure is damaged and the wrapping is no good. The two > factors in > > how tight you are "bending" are the core diameter (circumference) and the > > wrapping radius (distance from the center). > > > > Thanks again for the advice... Back to the drawing board. JHG > > > > > > John Gunderson, Associate Member, North Jersey Chapter > > > ---------------------------------------------- > > John, > > That wasn't given as an "optimum." More like a maximum. I'm still working > on the optimum part. > > Del
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