Action Elevations

Richard Brekne Richard.Brekne@grieg.uib.no
Mon, 20 Jan 2003 16:52:00 +0100


Bill, Dave Love, Ron... anyone else who might have insights and
thoughts...

I've been re-reading Hohfs article of a couple years back and am
wondering about the problem he sketches relating to the need for the
string plane to be paralell with the key bed. One of the points made is
that "most actions in common use today are designed to swing the
hammershank up to the point where it is parallel to the keybed" and a
statement following about the decrease in action efficiency when the
shank is not paralell to the key bed. In addition we want the hammer to
strike the strings at 90 degrees.

So first... if you have to choose the lesser of two evils... what would
you say is the right choice to make ? Keeping the hammer shank
centerline parallel to the keybed at strike distance or hitting the
strings at 90 degrees ?

Course you can alter the rake of the hammer to some degree, or even the
bore distance... but those present other give and takes.

Also... the Jist of Hohfs seires seems really to arrive at the optimal
string height for any given action, with key elevation, hammer bore,
center spread, and hammershank length as fixed values... holy grails as
it were.

Another question I am wondering about....

If the center spread is to be veiwed as a fixed value, and bore distance
is fixed..doesnt that sort of dictate the height of the hammer shank and
whippen centers over the keybed ?


Thanks for your thoughts

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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