More cut-off bar questions

[Overs Pianos]

>----- Original Message -----
>From: "David Love" <davidlovepianos@earthlink.net>
>To: "Pianotech" <pianotech@ptg.org>
>Sent: July 15, 2003 9:01 PM
>Subject: More cut-off bar questions
>
>
>>  I'm looking at (or under) a Boes today and noticing that the cut-off bar
>>  goes from the straight side to the belly rail but does not contact the
>>  beams.  Previous posts on this topic have suggested the necessity of
>>  affixing the cutoff bar to the beams as well.  Is there any compelling
>>  reason to do it one way or t'other.
>>
>>
>>  David Love
>>  davidlovepianos@earthlink.net
>>
>
>The idea of a cutoff bar is to physically and acoustically cut off, or
>shape, the soundboard. To do this most efficiently requires that the cutoff
>bar be reasonably stiff and massive. Physically attaching the cutoff to the
>belly braces both stiffens the bar and (by coupling to the braces)
>increases the apparent mass of the bar. By floating the cutoff as you
>describe simply decreases its efficiency somewhat.
>
>Del

Exactly Del, and they do it without fixing the cutoff to the beams so 
that the cutoff can be fitted with the sound board, without having to 
bother about the fit of the cutoff to the beams. Its really not the 
best way to do it, but the salesman still have something to talk 
about, even if it doesn't work quite so well.

When the cutoff is attached to the beams, it truly does become a 
sound board rim in its own right. The easy alternative is basically a 
claytons-cutoff, especially in the case of the Böse since it is made 
from spruce.

Ron O.
-- 

OVERS PIANOS - SYDNEY
      Grand Piano Manufacturers
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