Overs' I-rib sound board - first info

[Overs Pianos]

>Ron,
>
>This seems a good idea.  I see that you say that the rib is 60% 
>stiffer than a conventional rib.  Is it as light or lighter than a 
>conventional rib?
>
>Phil Ford

Hi Phil,

They are 25% lighter than a 25 mm X 25 mm rib at their centre where 
the bottom flange is full width. Once the bottom flange is tapered 
they become lighter still. This works very well in the mid to low 
bass areas where less weight is a distinct advantage. However, the 
treble requires a certain mass to function properly. We keep the 
treble ribs deeper than usual in the treble to maintain mass and to 
increase their load carrying capacity. The uppermost ribs for many 
conventionally ribbed pianos only measure around 20 X 20 mm, which is 
possibly a bit light on. The I-rib is about 10% heavier than ribs of 
that dimension.

I've got another page nearly ready which shows the ribs under test on 
the bench. Might get it up tonight.

Ron O.
-- 

OVERS PIANOS - SYDNEY
   Grand piano manufacturers
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Web:    http://www.overspianos.com.au
Email: mailto:ron@overspianos.com.au
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