Down-Bearing for Old Board ESTEYaND RODS

[Farrell]

I don't understand your basis for saying "The crown is maintained by the
ribs, regardless of rim movement." If the board (and ribs) initially have a
crown, and the rim is absolutely rigid - no possible movement (foot-thick
titanium - whatever), it would seem to me that you could load several
hundred pounds on the board and it should stay crowned for a few hundred
years at least - even it were a compression crowned board. For the board to
collapse, the ribs (assuming they and/or the board are glued to the rim and
have NO movement) would have to compress in the long direction enough for
the rib to be straight. Obviously it would not be so hard for the board to
compress a bit perpendicular to the grain, but the ribs? I guess they would
not have to compress a whole lot. Can they compress enough? They would have
to, would they not?

But certainly if the rim did spread out a bit, it would tend to flatten the
board. So I should think the rods would help maintain crown. Yes? No?

Terry Farrell
Piano Tuning & Service
Tampa, Florida
mfarrel2@tampabay.rr.com

----- Original Message -----
From: "Ron Nossaman" <RNossaman@KSCABLE.com>
To: <pianotech@ptg.org>
Sent: Saturday, February 03, 2001 11:46 PM
Subject: Re: Down-Bearing for Old Board ESTEYaND RODS


> >Hey Terry
> >     I just got to thinking about  those rods in that minerature estey
with
> >all those shims.  sounds like a mason an H. idea .  I'm bettin that if
the
> >board had flown out of the piano the crown would've gone with it!   Have
> >seen masons lose there risidual crown   every time upon exiting the case.
I
> >firmly believe the rods ( centripital resonator) idea should be standard
> >equip. on all high end grands.  I've been convinced rims move and shift
over
> >time.
> >  Please let your fans know how the little fella turns out!
> >  Dale Erwin
>
> While I tend to agree that the rods are a good idea, I can't support the
> notion that they are for crown retention. They are there to stiffen and
> raise the impedance of the rim. The crown is maintained by the ribs,
> regardless of rim movement.
>
>
> Ron N
>