>> *Further, if we can't predict this sag, we can't predict the dynamic >> bearing and angle of string deflection, which means we don't know the >> pressure and are going to have a rough time of making any rib scale that >> isn't a shot in the breeze.* > > Who says we can't predict rib deflection? One of the first > things I did after Del ruined my life by getting me interested > in this stuff was to build a spreadsheet for designing ribs > from the string scale. Calculating deflection against bearing > load is exactly how I design rib scales. Works out pretty > close in the piano after it's built too. I didn't say we couldn't predict rib deflection, only that we need said data to do so. I hear you about the swamp though. > > >> *BTW, while I don't make CC boards anymore, I did apprentice in a shop >> for several years that made about 20 CC boards a year and I have to say >> it was like being in the Wild West. We were total cowboys. The only >> thing we paid attention to was emc (3.5%). Rib dimensions came right off >> the old board, the compression crowning was all over the place depending >> on the time of year and size of the panels/ribs, and we set distance >> bearing with the spare change in our pocket. Yee haw! Boy were those >> days fun and also one of the reasons that I'm so compulsive now. :)* > > And the reason those of us building RC&S boards have spent so > much time accumulating and trying to pass on this information. > We as builders think it's time to make an attempt to get > control of the processes and produce a less random product. > > Ron N Right on! Jude Reveley, RPT Absolute Piano Restoration, LLC Lowell, Massachusetts (978) 323-4545 -------------- next part -------------- An HTML attachment was scrubbed... URL: https://www.moypiano.com/ptg/pianotech.php/attachments/20080127/b7837326/attachment.html
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