Buttressed Arch. Question for Ron N.

[Fenton Murray]

5.5 is beginning to sound more like it.
----- Original Message ----- 
From: "David Love" <davidlovepianos at comcast.net>
To: "'Pianotech List'" <pianotech at ptg.org>
Sent: Saturday, April 15, 2006 12:05 PM
Subject: RE: Buttressed Arch. Question for Ron N.


> >From a design novices perspective, ribbing the panel at a 60' radius
through
> the panel and 6% emc seems inadequate to form enough crown especially in
the
> upper end of the piano.
>
> David Love
> davidlovepianos at comcast.net
>
> -----Original Message-----
> From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On
Behalf
> Of Fenton Murray
> Sent: Saturday, April 15, 2006 11:39 AM
> To: Pianotech List
> Subject: Re: Buttressed Arch. Question for Ron N.
>
> How are you
> crowning boards, incidentally?
> Ron,
> I'm doing my first solo flight on an upright. Ribs at 60'. Go bar press.
> Getting ready to rib the panel at emc about 6. RH in my area typically in
> the 60's all year.
> ----- Original Message ----- 
> From: "Ron Nossaman" <rnossaman at cox.net>
> To: "Pianotech List" <pianotech at ptg.org>
> Sent: Saturday, April 15, 2006 8:03 AM
> Subject: Re: Buttressed Arch. Question for Ron N.
>
>
> >
> > > Yes, better, thank you. As one guy building soundboards, I'm not sure
> how to
> > > use this info. but it helps me to understand the system.
> >
> > That's what the information is for - understanding what is,
> > and more important in this case, what is not. How are you
> > crowning boards, incidentally?
> >
> >
> > >IS there a force
> > > pushing the rim out,
> >
> > No, there is not. There is some rotational force on the belly
> > rail from string downbearing because it's cantilevered, but it
> > has no affect on crown.
> >
> >
> >
> > >and is there any advantage to trying to make that rim
> > > immoveable,
> >
> > Absolutely. I routinely add bracing to the straight side, and
> > particularly to the belly rail (mass too, here). It doesn't do
> > the slightest thing for crown, but it raises the impedance of
> > the rim and belly rail so it absorbs less of the soundboard's
> > energy, improving tone and sustain.
> >
> >
> > >and is there a consequence to it moving with respect to the
> > > soundboard?
> >
> > Yes, it absorbs energy that should ideally stay in the soundboard.
> > Ron N
> >
> >
>
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