Inertia, was "Grand Touch"

[Ron Nossaman]

> Ron N's fix of adding the hardwood shoe at the balance rail hole on the
> other hand will make a huuuge difference. Why? Because he is increasing the
> stiffness at the outer fibers where it does the most good: at the point of
> the greatest weakness (balance rail hole goes through the outer web) where
> the key is experiencing its greatest bending stress. My quick and dirty
> calculations show the balance rail hole reduces the stiffness of the key at
> that point of greatest strain by at least 40%.

As Mrs Hatfield always insisted (annoyingly), show your work. 
Even so, the balance rail hole is a given (of sorts), and 
increasing the "reduced from" stiffness with a nominally stock 
balance rail hole produces a net gain in stiffness. This was 
the intent.


> The weakening effect of that balance rail hole on the keystick beam cannot
> be overstated. It is the weak link in the system. The effect of any hole
> drilled for leads pales in comparison.

As does, I suspect, the leading in the key compared to the 
hammer weight that makes it necessary, which is what got us 
here with the usual drift, in the first place.


> I suspect cracks between the holes
> occur not because of bending stress per se, but because of the internal
> stress placed on the wood by swedging the leads in holes too close together.

"Too close together" being determined by the humidity swings 
and the elastic limits of the material. Perpetually arguable 
by an infinite number of the chronically uninformed.


> But I've been wrong before. :-)
> 
> Dean

<G>

Ron N