Think rotate upward instead of pull in. Place a long flat stick across an open space supported at each end and press on the middle of it. Watch the the rib ends move/rotate upward not out .
Dale Erwin... RPT
Mason & Hamlin/Steinway/U.S pianos
www.Erwinspiano.com
209-577-8397
-----Original Message-----
From: Euphonious Thumpe <lclgcnp at yahoo.com>
To: pianotech <pianotech at ptg.org>
Sent: Thu, May 24, 2012 6:22 am
Subject: Re: [pianotech] [CAUT] Fwd: Mason & Hamlin soundboard model with tuning fork
P.S. I can envision how, given the right construction, the top edge of the ends of a soundboard panel might tip inward when the top of the crown is pressed upon; but that the entire assembly would pull in at the edges remains too hard or me to fathom.
In any event, we discussed this at length several years ago, and I have no taste for repeating that experience, so I humbly request that you please provide a video of this phenomenon, if you wish to prove your point.
Thumpe
From: Euphonious Thumpe <lclgcnp at yahoo.com>;
To: Euphonious Thumpe <lclgcnp at yahoo.com>;
Subject: Re: [CAUT] Fwd: Mason & Hamlin soundboard model with tuning fork
Sent: Thu, May 24, 2012 12:35:20 PM
pianotech at ptg.org
From: Euphonious Thumpe <lclgcnp at yahoo.com>;
To: Prof. Euphonious Thump <lclgcnp at yahoo.com>;
Subject: Re: [CAUT] Fwd: Mason & Hamlin soundboard model with tuning fork
Sent: Thu, May 24, 2012 12:33:13 PM
From: Euphonious Thumpe <lclgcnp at yahoo.com>;
To: Prof. Euphonious Thump <lclgcnp at yahoo.com>;
Subject: Re: [CAUT] Fwd: Mason & Hamlin soundboard model with tuning fork
Sent: Thu, May 24, 2012 12:25:20 PM
Dear Mr. Nossaman,
I readily, and without shame, admit that you are far more versed in both the art and craft of piano rebuilding than myself; and sympathy poureth from me like ambrosial founts that you must, perpetually it seems, suffer the encompassation of idiots such as myself. (Please forgive!) But for many of we Deficients, saddled as we are with the grave burden of inferior intellects, the pronouncement that a flexed plane, when pressed upon its apogee,
would contract at its extremities rather than expand, remains, sadly, a "far fetch". But surely a midge of the sunshine of compassion that glueth the cosmos together also dwelleth within you, so you need not, like some wrathful god of a heathen clime, infer that all we mental midgets accept your word as fact merely because you say it; nor consign us to replicating the empirical tests you laboriously executed and cite. So your beneficent nature will surely allow itself to favor we peons with a youtube video of this phenomenon, which, to those of we who were dropped upon heads in infancy, or bottle-fed, seems to defy all currently recognized laws of physics.
Most Respectfully,
Thumpe
From: Ron Nossaman <rnossaman at cox.net>;
To: <caut at ptg.org>;
Subject: Re: [CAUT] Fwd: Mason & Hamlin soundboard model with tuning fork
Sent: Wed, May 23, 2012 8:41:18 PM
On 5/23/2012 7:48 AM, Euphonious Thumpe wrote:
> Should it not be remembered that the M&H turnbuckle device does not
> CREATE crown ( that is done during board construction) but rather is
> intended to merely preserve it (in all planes, even if ever so slight)
> by preventing "case spread"?
It doesn't do that either. When a crowned rib and soundboard assembly, or model, is perimeter supported and loaded in the middle of the rib, the rib ends pull in rather than pushing out. It's not an arch, which anyone could have easily demonstrated at any time in the last hundred years or so exactly as I did by actually trying it instead of sitting around speculating. So the M&H crown retention devise doesn't retain crown. Try it for yourself and see.
> Could not the value of the M&H device be simply demonstrated by
> temporarily removing one, and making a scientific before/after
> analyzation of tone? ( In same RH, temperature, barometric pressure and
> etc..)
Again, trying it and finding out is apparently too simple when speculation can be nursed along virtually forever.
Ron N
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