Actually, think of a feathered rib with the <3/16” high ends set into notches in the rim and with the main body of the rib extending well below the bottom of the notch. When the center of the rib is pressed down the ends of the ribs—if you can see them move at all—will pull in very slightly. and, on a more practical level, think of that 4” (±) thick hard maple rim structure and then think of that <3/8” soft spruce soundboard panel and—what?—a 3/16” (or thinner) rib end spaced every few inches and think to yourself, “in a bending contest which of these is going to give first?” Even if Ron’s point about rib geometry were not correct—though it is—the argument about the movement of the soundboard affecting the structure of the piano ends right here. As does the argument about the rim sustaining soundboard crown over time. ddf Delwin D Fandrich Piano Design & Fabrication 6939 Foothill Court SW, Olympia, Washington 98512 USA Phone 360.515.0119 — Cell 360.388.6525 <mailto:del at fandrichpiano.com> del at fandrichpiano.com — <mailto:ddfandrich at gmail.com> ddfandrich at gmail.com From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf Of Dale Erwin Sent: Thursday, May 24, 2012 7:46 AM To: pianotech at ptg.org Subject: Re: [pianotech] [CAUT] Fwd: Mason & Hamlin soundboard model with tuning fork Think rotate upward instead of pull in. Place a long flat stick across an open space supported at each end and press on the middle of it. Watch the the rib ends move/rotate upward not out . Dale Erwin... RPT Mason & Hamlin/Steinway/U.S pianos www.Erwinspiano.com 209-577-8397 -------------- next part -------------- An HTML attachment was scrubbed... URL: <https://www.moypiano.com/ptg/pianotech.php/attachments/20120524/36e30d0c/attachment.htm>
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