Adjusting wippen assist springs

Richard Brekne Richard.Brekne@grieg.uib.no
Fri, 12 Dec 2003 00:56:27 +0100



gordon stelter wrote:

> Ah, yes, Rick. But would not decreased key inertia be
> a very nice thing for we fools who must play,
> sometimes, 4 hour gigs ???  Sometimes I can only stop
> when my fingers have swollen up like suasages and
> split open.( Blood on the keys can be hard to remove.)
>      Thump
>

Er.. thumpy.. I think you need to re-read  the post below. Sure reduced
key inertia would be a good thing.. but not if the overall action
inertia is higher... or if the apparent lightness of the action at soft
play fools you into thinking its just as light at heavy play... causing
more injury.... or if some other unknown consequence dedeats the purpose
of lowering the key inertia.... none of which has been adequatly shown
one way or the other.

I'm just saying there are a lot of claims being made about what does
what, whats significant and whats not, a lot of it contested
emphatically, and not much of any of it can really be shown to be known
or adequately quantified one way or the other.

I'm just raising the questioning finger... not trying to provide "the
definitive answer".

But just so we are clear... many if not most assist spring actions these
days are driving SW levels that are high enough to cause your wrists and
fingers plenty of problems..... low key inertia or not. So even there...
they are not being used conciously to cover all ends as it were.
Basically assist springs are still being used to overdrive the action.
At least thats how it appears to me.

Cheers
RicB




>
> --- Richard Brekne <Richard.Brekne@grieg.uib.no>
> wrote:
> >
> >
> > Sarah Fox wrote:
> >
> > > This is true, but only if one looks at the input
> > side, without regard to
> > > output.  With greater spring assist and less
> > leading, that same 200 g of
> > > force will produce greater hammer velocity and
> > therefore more sound.
> > >
> >
> > One of the thing Jim Ellis keeps banging away at is
> > that it is the hammers
> > interia that domninates this whole picture. The keys
> > intertia is only a small
> > part relative to that. And his reasoning for
> > discounting much of the touting of
> > reduced key inertia enthusiasts makes sense. The
> > mass of the hammer remains the
> > same, so does the mass of the whippen. The actual
> > amount of force needed to move
> > the added inertia at the key (assuming reasonable
> > levels of key leading) is not
> > nearly so significant a factor as its made out to be
> > then. And tho you do gain
> > some small amount in terms of overall action
> > inertia, you still dont get around
> > the change in touchweight gradient.
> >
> > Still the point you raise has never been quantified
> > to my knowledge... and it
> > would be nice to get a "net result" figure to see
> > just exactly what is gained,
> > what is lost, and what the side effects are.
> >
> > Cheers
> > RicB
> >
> >
> > >
> > > How?  If a greater proportion of your
> > counterbalancing is done by spring
> > > force, rather than key leading, there is
> > considerably less inertia to fight
> > > in the key during hard playing.  Remember, the
> > kinetic energy of the hammer
> > > is transferred to the strings (to a greater or
> > lesser extent, depending on
> > > the resiliency of the hammers), while the kinetic
> > energy of the keystick is
> > > transferred into the front rail, where it makes no
> > sound but a "thud."  The
> > > higher the ratio of hammer inertia to keystick
> > inertia, the lesser the input
> > > energy that must be delivered into the key to
> > transfer a given amount of
> > > energy to the string.
> > >
> > > Peace,
> > > Sarah
> > >
> > > _______________________________________________
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> >
> > --
> > 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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>
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--
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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