String breakage in relation to hammer mass

[Delwin D Fandrich]

> In a message dated 11/28/1999 3:27:58 AM, Michael wrote:
>
> <<"If a hammer is unusually heavy will it contribute to string breakage?
>
> Michael">>
>
> Michael;
>  The short answer is yes. The long answer is yes, explained by
E=MC(squared) > :-)

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The short answer is maybe, but probably not by itself.

The reason for this answer is explained by the concept of piano action
saturation.  The maximum amount of energy any hammer can transfer to the
string(s) is, indeed, limited by its mass and its velocity at impact.  And
the heavier hammer would have more energy than the lighter hammer if its
impact velocity were the same. But it won't be.  Action transfer efficiency
varies with the specific design of the action (specifically including the
length and height of the keys) but with all playable piano actions the
actual hammer velocity is limited by the bending and compressing of the
various action components.  There is more bending and compressing of action
parts with heavier hammer which limit its velocity.  The actual amount of
energy transfer is about the same.

Go back and read the articles or attend the next class -- if I ever do one
again -- for more details.

What does make a difference is the shape of the hammer at the striking point
and, more importantly, the density -- or the lack of resiliency -- of the
hammer.  Hard, dense, hammers will impact the string with much more of a
shock than will a softer, more resilient, hammer.  This puts essentially the
same amount of energy into the string, but at a much faster rate.  This is
pretty hard on the strings, but it does help to make up for design
deficiencies in the soundboard and rim.

Regards,

Del