Too Much Crown?

[Farrell]

Ron, I'm suprised you didn't catch my impossible soundboard configuration: I
had posted: "there is about 1/4 (crown) parallel with ribs, (and) 11/16" of
crown.....perpendicular to the ribs." That would require the rim/belly bar
to be a bit more than a 1/4" deviant from a plane.

I was driving home from my local PTG chapter meeting last night thinking
that :"Oh, no, I can't believe I posted that. I know who is going to catch
that one. It'll be Ron. And he will cut me up into little pieces!"

The measurement I made with the straight edge on  top of the soundboard was
in error. I measured the gap under both ends near the edge of the soundboard
and added them together and got twice the amount of crown present. DAAAH!
So, reevaluating the data, the board has a little more than 1/4" crown in
BOTH directions, suggesting that the rim/belly bar in fact are part of a
planar surface, as it should be.

Whew, I feel better now. So now my only wierd thing with it is bending the
bridge the 1/4". I did try it yesterday, just to see if I could close the
gap. Closes fine (and it was easy to do quickly with my handy go bar
system!).

Terry Farrell
Piano Tuning & Service
Tampa, Florida
mfarrel2@tampabay.rr.com

----- Original Message -----
From: "Ron Nossaman" <RNossaman@KSCABLE.com>
To: <pianotech@ptg.org>
Sent: Monday, September 11, 2000 7:35 PM
Subject: Re: Too Much Crown?


> >I stared at it for a while trying to figure it out. Got a string and a
> >straight edge out. Under the soundboard with the string measuring
> >perpendicular to soundboard grain and parallel with ribs, there is about
1/4
> >inch of crown in board (not really a crown, but rather a "V" with the
apex
> >under the treble bridge). Put the straight edge parallel with and
adjacent
> >to the treble bridge and WOW there is a whopping 11/16" of crown parallel
to
> >the soundboard grain and perpendicular to the ribs. If you sight down the
> >treble bridge, it is fairly straight. It would appear that this is why
the
> >bridge end sprung up.
snip
> Ron N
>