More on soundboard crown

[Delwin D Fandrich]

This is a multi-part message in MIME format.

---------------------- multipart/alternative attachment

  ----- Original Message -----=20
  From: Richard Brekne=20
  To: Pianotech=20
  Sent: August 19, 2003 10:13 AM
  Subject: Re: More on soundboard crown


   =20

  Hi Del... actually... I was rather thinking (again perhaps another one =
of those bunny trails...) that perhaps one could add about a 1/8th inch =
thick strip of left over sounboard material to the top half of the rib, =
grain in the same direction as the panels. If it was dried to say 6.5 MC =
prior to attachment to the rib... and the soundboard was dried to say =
4.5 MC why wouldnt this tend to sort of buffer the ribs cross grain =
constraint ? When taking on humidity this layer would get slightly =
compressed by the rib... and since its grain is in the same orientation =
of the panels it wouldnt force that into nearly as much compression.... =
er.. I think :)... If there was not enough crown you could rib crown =
enough to make up the difference. I suppose you could rib crown to begin =
with.. but if this provided a kind of solidly glued  << slip joint >> , =
and if there was some good reason to dry out the panel to 4.5 MC as long =
as one could avoid exceeding the stress limits... well... Anyways.. I'm =
just fooling with ideas in attempt to better sort out what does and =
doesnt happen. yes ??=20

  RicB=20



I fail to see the point. Any time you dry a soundboard panel that far =
down there are going to be compression problems later on. Period. There =
is no way to "buffer" it. Unless, of course, you leave the panel free of =
constraints and let it float free. I.e., ribless and unattached. It is =
the MC in the panel--actually, the lack thereof--that is the problem. =
Since leaving the panel free and unattached is not a practical solution =
the simplest way to avoid the problem is to not dry them out that way.

This is nothing I'm even remotely interested in working on. As you say, =
why not just crown the ribs? It's a simple and effective solution. It's =
a well known technology that has been around long enough that its =
working characteristics and advantages are fairly well known. And, by =
now, it's a technology that should be well accepted. Of course it is by =
many in the industry. And it would be by many more if it weren't for the =
monumental weight of tradition and design lethargy endemic to the =
industry. Personally I just don't see any reason to keep beating away at =
what I see as a dead horse. It's not going to come back to life--it's =
just going to keep right on being dead. The best you can do is tenderize =
the meat a little. Life, and most of the piano industry, moves on.

As always, you're encouraged to design and construct an experiment. I'll =
not bother...I'm quite content with the rib crowning techniques I've =
worked on and refined over the years.. =20

Del

---------------------- multipart/alternative attachment
An HTML attachment was scrubbed...
URL: https://www.moypiano.com/ptg/pianotech.php/attachments/37/a5/8f/5c/attachment.htm

---------------------- multipart/alternative attachment--