Key MOI and FW data

[Richard Brekne]

Mark Davidson wrote:
> 
> Ricb wrote:
> 
> >Nice stuff Mark. I would think a few hundred such samples
> >would be a good basis for a real meaningful data base
> >from which to start drawing conclusions.
> 
> Isn't that about the number of pianos you have there at the conservatory?
> Or maybe we could do something like a "Piano key inertia road show" where
> people bring their old pianos in and we measure their key MOIs.

We have fifty five right now. 18 grands. Still.. its a start. Maybe a
few of us should agree on means and standards and actually compile a
d-base to see what pops up ??

> 
> >How do you explain the FW's being higher values then
> >MOI in the bass, and then lower for the rest of the piano ?
> 
> Not sure there's any real relationship like that.  Measuring different
> things, different units, etc.  I just put them on the same graph because it
> helps to see that yes, the big dips and bumps do come at the same places.
> Also remember that an unleaded key is almost balanced - the FW results
> mostly from lead, while only about 30-40% of the key inertia in the bass is
> due to lead, so these curves will look a bit different.  Key inertia will
> never go much below 20 kg cm^2. (Different slopes and Y-intercepts, your
> math teacher would say)

I'm sure. But still... if that same thing keeps on showing up piano
after piano ... then I'd be curious as to a more definitive explaination
as too why.

> 
> -Mark
> 
>

RicB