laminated ribs

[Erwinspiano at aol.com]

Ron  wrote
 Maybe assumptions are being made that aren't the case. The 
boards I'm  building, and the boards Del's building too (from 
his descriptions), aren't  stiffer than new CC boards, except 
possibly in the treble. A new and well  made CC board is 
overall stiffer ( has a higher spring rate under full  bearing 
load) than the boards I'm building. 
 
Ok, stiffer from the git go & a steady reduction of  resistance over time 
also changing it's impedance
 
 But my boards have a 
spring rate higher than the failed,  cumulative compression 
damaged CC boards with the killer octave  problems.  Lacking 
significant panel compression, my boards don't  have the steep 
progressive spring rate of both CC, and RC with panel support  
boards, like you're building.

Is that any better?
  Ron N
 
  Yes but Define steep progressive spring  rate.  I assume we're  talking non 
linear 
  
       Yes and perhaps  assumptions are being made in my case too.  I've been 
ribbing at about 6%  lately so my evolutionary process continues. At what 
point is panel compression  a virtual non factor any way?  I find my overall 
Crown compression to  be  a bit more in the tenor area than in the treble and  
I've  measured  2.5 to 3 mm residual crown in the killer  octave lately & I 
continue to monitor this. I think variable amounts of  rib radius designs are 
getting pretty common so were likely to  document  more similar results.
  I'm typically using the Ronsen Wurzen or Steinway hammers  with a medium 
density feel to the felt when I needle.  Anyway hammer  stiffness is another 
cool way to bench mark belly assembly  stiffness.
  Dale






-------------- next part --------------
An HTML attachment was scrubbed...
URL: https://www.moypiano.com/ptg/pianotech.php/attachments/20060329/a3e73f40/attachment.html