Key Inertia

[Mark Davidson]

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John Hartmann wrote:

>The points are:

>1) The only force that gets transferred to the string is that portion =
of=20
>the force applied at the key that works to accelerate the hammer and =
shank.

Agree.  But note that not all of the hammer's energy is transferred to =
the string. The hammer bounces off and is still moving, so it still has =
energy, which is also wasted.  But I think you mean that none of the key =
or wippen energy makes it to the string, with which I agree.

>2) The portion of the force applied to the key used to accelerate the=20
>key and wippen do not go into into the string but are wasted.

Agree.

>3) Removing mass from the key and wippen will make the action more=20
>efficient.

Hmm.  Starts to get fuzzy here.  If you keep the same speed, so less =
energy is wasted, then I agree. But if you remove mass and play the key =
with the same force, you will have more speed, not the same speed.

>4) Given our ideal action with no bending and friction losses changing=20
>the hammer mass does not effect the efficiency of the action.

Same problem as 3.  If you don't change the mass of hammer and wippen, =
and keep the same key speed, you will waste the same amount of energy.  =
But again, if you add mass to the hammer and keep the same force on the =
key, you will have less acceleration, less speed, less key/wippen energy =
wasted.


So I guess I agree with 1 and 2, but for 3 and 4 we need to define =
"efficiency" before we can talk about whether it stays the same or not.

-Mark
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