Key Leads and Inertia

[Richard Brekne]

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Phillip Ford wrote:

> The acceleration at the breakpoint is determined by the relative location of the lead to the finger force.  However the force at the breakpoint is dependent on key parameters.  You need both to locate the breakpoint.  I would think that Ik and rk are going to be dependent on the key ratio.  Changing rk changes the key ratio.  Changing rk also moves mass M changing the CG of the key and consequently Ik.
>
> Phil F

Ok.. forget my last... going through the formulas at the appendix cleared things up I think.  Check me here will you Phil (and anyone else who wants)...

The breakpoint location is determined by  a = (r/rb)g, but to find the force needed to achieve that accelleration you need to substitute (r/rb)g for << a >> in the equation for Force.. i.e.


     [Image]
     becomes

     [Image]

     and reduces to

     [Image]

Which at least shows that the breakpoint force is dependant on the key ratio... or better said dependant on the both the mass and the center of mass of the reference key. Tho I dont see why you need to know this to locate the breakpoint. Rather it seems that knowing the location of the breakpoint is neccessary to find this breakpoint force.

or what ?? grin.



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


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