Key flexing, was "Inertia," was "Grand Touch"

[Ron Nossaman]

> Are the button and top plate two pieces or one? 

Hi Dean,
They're two separate pieces.


>If they are two why not make
> it just one and do a gradual taper all the way to the end of the top plate.
> I suspect you would pick up some additional stiffness.

Interesting thought. No reason not to that I can see, other 
than the machine setup to produce the tapers. The net effect 
is similar to a taper anyway, so it's a quite reasonable 
approach. The difference that comes immediately to mind is the 
bushing method. With two layers, the buttons can be bushed 
from the bottom. With one double thick button/plate, the 
bushing would have to be done from the top. Hardly 
insurmountable, and bears looking into. I'll ponder it, thanks.


> Since the top of the key is in tension I would think you get much more
> strain reduction by stiffening the top.
> 
> Dean

There's where it gets foggy. The only thing I've ever found 
even remotely hinting at the weak spot in beam failure 
described fiber stress in compression as being the likely 
limiting factor. Logically, adding beam depth with a 
reasonably similar material to the original just adds 
stiffness by virtue of added beam depth, regardless of whether 
it's on the top or bottom. That's the "duh" factor. 
Substituting a different (harder) material might well make 
some difference as to whether it's on top, or on the bottom, 
but I sure haven't found any documentation to that effect 
despite a lot of hours of looking. So far, it's in the same 
category as grain orientation as affects beam stiffness and 
long term load carrying capacity - unverifiable 
intuition/random guess. Functionally, I'm not convinced it 
makes enough difference to get excited about, but I'm 
certainly willing to entertain the concept pending better 
information than I currently have.

Got any?

Ron N