Crown in Bass Area & Downbearing

[David Love]

Although what I meant was that longer backscale will require a greater
angular measurement.  

David Love
davidlovepianos@earthlink.net


> [Original Message]
> From: Farrell <mfarrel2@tampabay.rr.com>
> To: Pianotech <pianotech@ptg.org>
> Date: 5/13/2004 3:40:23 AM
> Subject: Re: Crown in Bass Area & Downbearing
>
> I should probably backtrack somewhat on my statement of "very little crown
> in the bass" - but only somewhat. I think many designs will have ribs in
the
> bass area that are cut to a 60-foot radius (some even larger). That to me
is
> little crown. Some soundboards are made from flat ribs and it seems it
does
> not take too terribly long on some of these to get flat-ish. These are
> definitely little (or no, or negative) crown. Regarding downbearing on the
> bass, I am aware that some reputable folks building and installing new
> soundboards just have bass strings kiss the bass bridge top - zero
> downbearing - regardless of backscale length. Apparently, they find that
> works to their satisfaction with the design of their soundboards.
>
> As David points out, the expression of downbearing as a unit of length not
> only lacks clarity, it is meaningless without a backscale length
> specification. I wish downbearing was commonly characterized with an
angular
> measurement - or better yet, two angular measurements - bridge front and
> back downbearings.
>
> Terry Farrell
>
> ----- Original Message ----- 
> From: "David Love" <davidlovepianos@earthlink.net>
> To: "Pianotech" <pianotech@ptg.org>
> Sent: Wednesday, May 12, 2004 10:59 PM
> Subject: RE: Crown in Bass Area & Downbearing
>
>
> > The amount of downbearing in the bass should, as I understand it, depend
> on
> > the backscale length.  The greater the backscale length, the more
> > downbearing is not only tolerated but needed in the bass area.  A next
to
> > zero downbearing would probably be advisable where the backscale is
> > extremely short.
> >
> > David Love
> > davidlovepianos@earthlink.net
>
>
> >But many designs incorporate very little crown in the bass and zero or
> >nearly so bearing on the bass bridge. So how could you tell that such
> >characteristics were a problem (at least in terms of deviation from
> original
> >design)?
> >
> >Terry Farrell
>
>
> > Regarding bass crown, I'm not sure how much is design intent, and how
much
> > is the result of the cantilever under positive bearing destroying what
> > crown was there. I tend toward the notion that the crown was originally
> > there, designed or not, and the cantilever killed it - if it is indeed
no
> > longer there. The downbearing would ideally be dependent on the length
of
> > the back scale, like David Love said. I consider zero crown and zero
> > bearing to be a problem in a piano with a conventional soundboard,
> anywhere
> > in the scale.
> >
> > Ron N
>
>
> > > Terry said: "But many designs incorporate very little crown in the
bass
> > and
> > > zero or
> > > nearly so bearing on the bass bridge...."
> > >
> > > Terry,
> > > Where did you get such an idea. It's simply not true!
> > > Regards,
> > > Joe Garrett, RPT, (Oregon)
>
>
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