Foundry Castings

[Richard Brekne]

Phillip Ford wrote:

> > The basic characteristics for gray iron used in
> > piano plates are pretty well documented and
> > well known. Have been for a long time and I see no
> > reason to bring these into question.
>
> I do.  The main thing I question is whether or not the high damping of gray
> iron is a desirable thing.  Many people seem to assume it is.  I'm
> unconvinced.  But if it is important or desirable, that means you either have
> to use gray iron or incorporate some damping means into your design if you
> choose to use something else.

Well now here is an interesting point, and I see Del also takes this line. And
here I am sure I speak for most every one in sincerly wishing you both well in
this. If you find that you are correct, that the internal damping of grey iron is
a liability for good piano sound, and find another material that surpasses the
present standard in acoustic performance and still is viable in all other regards
then you will have really accomplished something big time worthwhile.  For that
matter even showing conclusively that internal damping in piano plates is a bad
thing would be quite the shake up  me thinks. Go for it !

>
> I'm not interested in overwhelmingly convincing the industry.  I'm interested in
> convincing myself.

We share a common trait in this respect methinks Phil.

> > Until then I think gray iron will continue to
> > be used, not because of tradition or some long
> > lost reasons that nobody remembers anymore....
> > but because its the best stuff around for the
> > job... until somebody actually proves something
> > else is.
> >
> > My Two bits
> >
> > RicB
> >
>
> I agree.  I think gray iron is a good choice for this application, and when
> high production is the environment and cost is a big factor, then it's
> probably the best choice.  I haven't tried to argue otherwise.  But I do think
> there are other viable alternatives.  And in a different production
> environment or with design objectives or priorities that are different than
> those of a large manufacturer then I'm not convinced that cast gray iron is
> the best choice.
>
> Phil F

Thats whats great about the will to try new things and to continually be open for
new alternatives. Myself I dont see it when it comes to grey iron and piano
plates, but dont get me wrong, I applaud anyone to earnestly tries to see if there
is another, a better way.

--
Richard Brekne
RPT, N.P.T.F.
UiB, Bergen, Norway
mailto:rbrekne@broadpark.no
http://home.broadpark.no/~rbrekne/ricmain.html