----- Original Message ----- From: "Ron Nossaman" <RNossaman@KSCABLE.com> To: <pianotech@ptg.org> Sent: January 23, 2001 6:21 AM Subject: Re: New, Improved Baldwins > > > The ribs and board are now radius crown. > > Yes, at (I think) 72', and the improvement in the lone sample I tuned was > evident. I'm looking forward to comparing it to more Ls for a continuity > check. I wonder how that radius was arrived at. Baldwin's grand ribs have been cut to a 72' radius for many years. At least since the late 70s or early 80s -- beginning well before my time there, anyway. Crowning was (is?) supposed to be a combination of rib-crowning and compression-crowning -- though no one I met or worked with at the factory during the 1980s had any understanding of what that meant so it didn't always get done correctly. I was told that the 72' part goes back to their days in Cincinnati and it was really supposed to be a 60' radius. (We all know that there is real musical magic in a crown radius of 60', right?) According to the story, a steel template had been ordered from a machine shop that also did work for the aircraft industry. The machine shop looked at the order and contacted Baldwin and asked if the 72' radius would be all right since they already had something almost identical to the piece Baldwin wanted --but it had a 72' radius instead of the specified 60' radius -- that they had done for one of their aircraft clients that had changed their minds, or cancelled or something and it would save everybody a lot of money... Baldwin looked at the numbers and agreed and the 72' radius became the standard. Go ahead and do the numbers...they really are quite close. Close enough for the time, anyway. > >You will also notice the ribs are notched to > >the inner rim. > >(Depends on Ser#) > > Yes, but I'm not sure it's necessary to anything specific, one way or the > other. Why would that be a feature? The one place this is important is along the inside curve of the rim along the treble side where the grain angle of the solid-spruce soundboard roughly parallels the curve of the rim. If the ribs are not set into notches in the rim through this region the soundboard has a slight tendency to develop a crack just at the intersection of the board and the inner rim. (Obviously, this would not be a factor with laminated soundboard panels.) As well, from this region up, Baldwin soundboards -- most others, come to that -- can use all the stiffness they can get so the rim notching and rib inletting does help. From there down the practice is counter-productive and is generally detrimental to piano tone production (all other factors being equal, of course). > All in all, a step forward, even with the steps back. Don't stop now. Agreed. Del
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