Bellymen, I have been following this thread with great interest because it's part of what we do. CNC and CAD/CAM technology have allowed us to accurately offer these complex geometrical shapes for soundboard cauls and rib cauls for the CC, RC&S, and Hybrid crowds. Whether it be a Parabolic Curve, Catenary Curve, Sinusoidal, Multiple Radii, Hyperbolic or some other Trigonometric Function, our machine can do it. If you have a concept that cannot be fabricated with conventional shop equipment, we can help you out. We have many sets of cauls in the field already. Food for thought. Mike Blackstone Valley piano Michael A. Morvan 76 Sutton Street Uxbridge, Ma 01569 (508) 278-9762 www.pianoandorgankeys.com www.thepianorebuilders.com ----- Original Message ----- From: "Ron Nossaman" <rnossaman at cox.net> To: <pianotech at ptg.org> Sent: Thursday, January 29, 2009 11:59 AM Subject: Re: [pianotech] FW: laminated ribs again > > >> Hi, >> Dont know so Ima goina ask. >> Is there a crown ridge that sort of follows the bridge line? > > In a rib that's a constant radius circle segment, the high point is ALWAYS > in the center of the ribs. That's geometry, no matter what sort of "logic" > and body english is employed to try to make it not so. If the bridge is > centered on the rib then yes, the bridge is on the high point. If not, no. > With non constant radius crowning (parabola, sine, catenary, or multiple > radii), you can put the high point anywhere you like. > > >> Could one cut kerfs in the ribs radiating away from the bridge line and >> glue in wood shims >> to induce more crown? > > Sure, if you really want negative crown, unless you kerf and wedge from > the panel side. More geometry. > > Ron N > >
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