Leverage and Dip

[David Love]

The simplest way to look at this is with a teeter-totter.  With fulcrum
centered there is a 1:1 relationship with weight placed at either end,
100lbs will balance 100lbs and the arc scribed at one end will be duplicated
at the other end.  Move the fulcrum so that one side is twice the length of
the other.  Now, 100lbs on the shorter end will be balanced by 50 lbs at the
end twice its length, and the arc scribed by the short end will also be 1/2
of the arc scribed by the long end.  The 2:1 relationship is maintained both
in terms of force leverage and distance leverage.  Though a piano consists
of 3 levers, the overall relationship of input to output doesn't change.  At
least that is my understanding.

David Love


----- Original Message -----
From: "Richard Brekne" <Richard.Brekne@grieg.uib.no>
To: "Pianotech" <pianotech@ptg.org>
Sent: October 03, 2002 2:31 PM
Subject: Re: Leverage and Dip


Before we go on... :)  could we resolve what seems to be two mutually
exclusive standpoints here ?

Bill Ballard wrote:

> The problem is of course that there is no direct correlation between
> action leverage as measure by distance and by weight.

David Love writes:

>The action ratio not only refers to the relationship between change in
>weight at the hammer and the resultant change in weight at the key, it
also
>refers to the relationship between key travel and hammer travel...

snip snip.....

>At a ratio of 6:1, for example, 10 mm of dip
>will result in the hammer traveling a total of 60 mm.  (It also means
that a
>change in 1 gram at the key will result in a change of 6 grams in the
>balance weight.)


I dont mean to be a pain or anything... but you two seem to be saying
exactly the opposite about this, and its kind of a central point.

Thanks to both of you for some good reading... Its late and I have been
putting in 18 hour days this last week... so I will re-read both
tommorrow and get back to you.


Cheers

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


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