[pianotech] FW: laminated ribs again

[Mike]

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
>
>