Killer Octave Question

[Ron Nossaman]

>>Likewise, though load analysis of the rib sets being used and the bearing 
>>loads being placed on them (of those few I've checked) indicate to me 
>>that the panels are still carrying a significant percentage of the 
>>bearing load, even in some (most???) rib crowned boards.
>
>Exactly. I am building and testing five inch wide strips of panel with one 
>rib glued under it, set up as it might be in the piano (mounting it on a 
>steel section of RHS - to fix the ends prior to load testing), to check on 
>deflection under load, and to gain some insight into the relative load 
>carrying of the two, ie. the crowned rib and the panel compression.

And as you said, compression resistance is higher in the laminated panel, 
so the panel compression could support a greater percentage of the load, 
and/or for a longer time than the rib/panel crown hybrids we see. Lots of 
possibilities, nearly all positive.


>If we shape a rib so that the top profile has a 7 mm rise while the bottom 
>edge is straight, and after gluing a panel at 7% to the rib it rises a 
>further 1 mm in the middle when the panel normalises - if it is loaded 
>down such that the rib sinks out 3 mm it stands to reason that the load is 
>being shared by the rib and the compression in the panel. The big question 
>is what do we want between the two.

That is, indeed, the big question.


>  Still thinking about this over the next week.

And periodically for a long time yet to come, I'd guess, like some of the 
rest of us.

Ron N