Even balance weight or even something else, that'sthequestion.

[Richard Brekne]

Hi there David

Agreed with your below, and its really quite amazing what you can do to even
out the BW if you first put yourself to it, once you know what you are looking
for. Even without useing all that much extra time and effort.

One other point is that you have an equally handy Friction indicator built into
the whole thing. If  BW is fine, and yet your static DW (that you have to
measure anyways to get BW in the first place) is not where you want it, then
you look for a friction related issue.

Its all very very handy indeed, regardless of what kind of design you choose in
the first place... you can assure dead on eveness of each of these.

Those that assert that the dynamics of the action are not addressed by all of
this seem to overlook that both mass, friction and ratio taken thus are quite
central players in the dynamic perspective. Certainly the eveness created in
using a system such as PTD will be refected in that view.

Cheers

RicB



"David C. Stanwood" wrote:

> >Richard Brekne Wrote:
>
> >Front Weight specifications result in less then equally smooth Balance
> Weights
> >unless there is near absolute perfection in each and every point that
> affects the
> >total action ratio for each key. A nice diagnostic tool if its used for
> that, but
> >if such variance in total action ratio (however its taken) are left
> unimproved,
> >then that uneveness is reflected by an uneven BW curve.
>
> Yes and this is one of the beautiful points of an equation balanced action
> (PTD).  When SW and FW are set to smooth equation generated specs, the BW
> becomes an indicator of ratio variations.  If the Balance Weight is not
> right but all the weights are set to spec, then it has to be a ratio error.
>  The BW points out the error.  The kind of uneveness you find in the BW is
> usually on the order of + or - 2 grams on a good quality action, which is
> no problemo for pianists.  An advantage of action designs which incorporate
> adjustable support springs or variable gap magnets is that you can smooth
> out these variations.  In either case the BW in an equation balance action
> (w/springs or magnets OFF) can tell you if you have problem like a cocked
> knuckle or a capstan that's out of place.
>
> David Stanwood
>
> _______________________________________________
> pianotech list info: https://www.moypiano.com/resources/#archives

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