Nosing Around

[Farrell]

> The only one I can think of that is perhaps an exception (Most all of the
other nose bolts you
> encounter have a larger portion of the bolt that does not go through the
> plate which provides a lip that the various points of the plate sit on,
and
> then the smaller threaded portion which normally comes up through the
plate
> and gets the nut put on it.) is the single
> Steinway bolt that runs down through the plate in the treble end, the one
> that goes down into the "tone bell".  Most all of the other nose bolts you
> encounter have a larger portion of the bolt that does not go through the
> plate which provides a lip that the various points of the plate sit on,
and
> then the smaller threaded portion which normally comes up through the
plate
> and gets the nut put on it.  On the "tone bell" bolt, there is no lip on
it.
> It is normally set so that it's just past finger tight when the piano is
not
> under tension.  Once there is tension on the piano, you will need a wrench
> to move that bolt.

Gee Whizz Brian. Nice explanation, but your experience must be limited to
pianos manufactured by those high-end companies. I've had several plates out
of grands now and I have never seen a bolt like the "Most" that you
describe. In fact, I have never seen a bolt! Don't ALL great pianos have a
large wood screw going through the middle of the plate, through a hole in
the soundboard, and into the framing below?

Shamefully telling, eigh? But seriously, I have been assuming the way to
adjust these is to do as you describe for the "tone bell" bolt. Unless of
course you are purposely bending the plate to get desired downbearing on
these wonderful pianos that may not deserve a new board/bridge caps!

You made me laugh Jeannie. It's amazing where our minds can take us when
"zoning out" during a tuning!

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

----- Original Message -----
From: "Brian Trout" <btrout@desupernet.net>
To: <pianotech@ptg.org>
Sent: Friday, January 19, 2001 1:49 AM
Subject: Re: Nosing Around


> Hi Jeannie,
>
> Happened upon your post about nose bolts, and thought maybe I'd offer a
> thought or two, more or less off the cuff.
>
> The nose bolts provide points at which the plate is anchored to the
> underbelly, the wooden structure of the piano.  The outer plate bolts tie
> the outside edge of the plate to the inner rim, the pinblock screws tie
the
> plate web to the pinblock (and perhaps a bit more indirectly to the
> stretcher and again to the rim), and the nose bolts give the plate support
> at various points throughout the inner parts of the plate.
>
> Acoustically, fastening the plate solidly to the wooden structure of the
> piano effectively adds mass and stiffness to the whole assembly, and helps
> to contribute to even more solid string termination points.
>
> Those nose bolts, when well placed, will help the plate to resist
distorting
> under the weight of all of those tons of string tension, and plates do
bend
> and distort, more so than some might imagine.
>
> For the most part, when I'm setting a plate in a piano, I want it to sit
> solidly on whatever support is around the perimeter.  Up in the front,
> that's the pinblock.  Around the other edges, it's usually either sitting
on
> dowels or bolts or something similar.  When those points are set and
solid,
> so that the plate won't have to be 'bending' into position when the bolts
> are tightened down, then I'll set the nose bolts.  (Up until this point,
the
> nose bolts are wound down at least part way so that the plate is not being
> supported by them in any fashion.)  Now, one by one, I'll bring the nose
> bolts up so that they will just come in contact with the plate.  I don't
> want to bend the plate upwards or to put pressure on the plate.  The goal
is
> simply to have the plate sitting unflexed upon all of the points it is
> supported by.  And then, it's ready to be tightened down.  I can't give an
> exact measurement of torque readings that I'd use, but it needn't be so
> tight that no man will ever be able to loosen them again.  I go a fair bit
> past finger tight, but no large wrenches either.
>
> The only one I can think of that is perhaps an exception is the single
> Steinway bolt that runs down through the plate in the treble end, the one
> that goes down into the "tone bell".  Most all of the other nose bolts you
> encounter have a larger portion of the bolt that does not go through the
> plate which provides a lip that the various points of the plate sit on,
and
> then the smaller threaded portion which normally comes up through the
plate
> and gets the nut put on it.  On the "tone bell" bolt, there is no lip on
it.
> It is normally set so that it's just past finger tight when the piano is
not
> under tension.  Once there is tension on the piano, you will need a wrench
> to move that bolt.  This is another one that I believe is there to stiffen
> the plate by tying it to the underbelly, effectively providing a more
solid
> termination point on that end of the treble sting section, which now that
I
> think about it, might be the upper part of the 'killer octave' range.
> (Plenty more to ponder there...)
>
> Hmmm...  the mind is drawing a blank again.  I'm sure there are other
things
> to be added, maybe even some corrections to be made.  But those are the
> thoughts that came to mind just now.
>
> Amazing the things that we muse over while tuning, huh?
>
> Have a good day,
>
> Brian Trout
> Quarryville, PA
> btrout@desupernet.net
>
>