[pianotech] FW: laminated ribs again

[David Love]

I see what you mean--assuming the rib itself is not canted one way or
t'other.  

David Love
www.davidlovepianos.com


-----Original Message-----
From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf
Of Ron Nossaman
Sent: Thursday, January 29, 2009 9:25 AM
To: pianotech at ptg.org
Subject: Re: [pianotech] FW: laminated ribs again


> Well yes and no.  The circle radius is constant so the 'high point', or
full
> height of the rib can be placed anywhere in proximity to the bridge by
> tapering the bottom of the rib shorter on one side and longer on the
other.

Well, no and yes. The high point of the crown is always in the 
center of the rib. The thickest part of the rib, or the load 
center, can be put elsewhere. The concepts aren't 
interchangeable.


> The only place this is really an issue is in the high treble (assuming a
> bass cutoff is installed) where the bridge moves closer to the belly rail
> relative to the inner rim on the bent side.  Here you can keep the rib at
> full height under the bridge (or at least closer to the bridge) by
> shortening the taper on the belly rail side and lengthening it on the bent
> side.  I've done that on most of the boards that I've done without any
> problem--or perceived benefit if the truth be known.  
> 
> David Love

I do that too, but the high point of the crown is still in the 
center of the rib.
Ron N