soundboardinstal again

[Delwin D Fandrich]

----- Original Message -----
From: "Danny Boddin" <danny.boddin@pandora.be>
To: "Pianotech" <pianotech@ptg.org>
Sent: July 20, 2003 3:08 PM
Subject: Re: soundboardinstal again


>
> Another tought:
> Recently visiting Bechstein we were astonished to see that the production
of
> their bridges is completely machinemade, they come out notched and are
stocked ready
> with bridgepins on.
> We wonder how they can finish the assembly of this bridges on the board
with
> a precise I thought specific angle of the bridges, I can not belief that
the production of
> their soundboards is that standard even. Or are the deviations on each so
insignificant?
> We didn't ask.

There is no good reason why this cannot be done with reasonable--that is,
acceptable--precision. From a tolerance perspective the plate is probably
the biggest variable. But, with reasonable controls during casting and
subsequent milling and machining operations even this can be fairly well
controlled.

The critical areas are the high treble and the low bass. The high treble
can be controlled by varying the thickness of the pinblock or by using
shims between the pinblock and the top of the inner rim. The bass can be
controlled by simply varying the height of whatever spacers, wedges,
dowels, etc., that are used to position the plate off of the soundboard
surface. Or, as Baldwin does it; simply threading the holes in the plate
and using a threaded bolt to suspend the plate at the desired height. Once
the two ends are tied down to the correct height the rest shouldn't really
present much of a problem. Baldwin uses (used?) the most simple expediency
of positioning the string at the proper height along a vertical hitch.
Others use an easily adjustable back bearing piece. Still others simply
bend the plate (via strategically placed nosebolts).

The more I learn about pianos and the more I work with piano manufacturers
the more I wonder why so many insist on making their lives so very
difficult.

Del