Flat Belly Rail

[Overs Pianos]

>Is a flat belly rail a good idea then?
>
>Thanks
>RicB

It is around here. We're using a flat belly rail in our 225 pianos. 
By this I mean that there is no curvature across the span of the 
belly rail. The central area of our boards have nearly 10 mm of crown 
unstrung. When strung, a string line placed underneath the board will 
almost clear the sound board buttons. If the belly rail was crowned 
as well it would make for serious problems achieving a workable 
relationship between bridge height, bearing block height and the 
correct down bearing angle setting.

We do angle the belly rail and inner rim gluing face to the crown of 
the board. As Terry suggests, it probably isn't greatly important. 
But I like to do it just to know that the glue joint is good all the 
way across the interface. I'll pulled one original board which 
clearly had lots of crown when it was installed, but the inner was 
made flat. The glue joint was good around the outer edge but the 
inner edge was only just making contact or just off the rim. I can't 
say I'd be comfortable about such a gluing arrangement. It could very 
easily allow noise at the perimeter of the board in some instances.

Ron O.
-- 
OVERS PIANOS - SYDNEY
    Grand Piano Manufacturers
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Web http://overspianos.com.au
mailto:ron@overspianos.com.au
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