YC Strike Weights etc

[David Love]

Though the assist springs will take care of some problems if you miss, the
FW/SW relationship will not guarantee you a certain BW.  If you set the FW
at maximum and set up your SW's to a corresponding curve without measuring
the BW that  corresponds to that relationship you could end up with a nice
curve and a BW of 50.  I would check to see where the FW maximum (and I
would generally not set it at the maximum, it gives no room for adjustment),
puts your BW at a given SW.  Be sure that's what you want.  You can adjust
the SW if it isn't or examine the geometry to see if the knuckle radius/key
ratio is a good match.

David Love


----- Original Message -----
From: "Richard Brekne" <Richard.Brekne@grieg.uib.no>
To: <pianotech@ptg.org>
Sent: November 03, 2001 3:01 AM
Subject: Re: YC Strike Weights etc


> David Love wrote:
> >
> > ----- Original Message -----
> > From: "Richard Brekne" <Richard.Brekne@grieg.uib.no>
> > To: <pianotech@ptg.org>
> > Sent: November 02, 2001 2:13 PM
> > Subject: Re: YC Strike Weights etc
> >
> > > What do you mean by "convergence line" ?
> >
> > The magic line between...
>
> Ah yes.. never heard anyone call it this before..
>
> > The reason I think that it's important to know the BW is that you don't
know
> > where your FW's should be if you have no point of reference.
>
>
> But you do have a point of reference. And one that works
> great and results in a fine playing action. You have the SW
> curve and a table of FW maximums, and a set of clearly
> defined relationships to put these two into perspective. No
> doubt one can get more involved and much more creative using
> Stanwood proceedures..but BW can indeed be treated as
> something you yourself specify. In which case you dont need
> to know it ahead of time.
>
> > I think it's a  mistake to rely to heavily on the assist spring.  Nine
or ten > grams is
> > plenty (though I think you can go to 15 with problems of bouncy keys).
By
> > comparing the BW with the FW's (with assist springs detached) you can
tell
> > how much you will have to rely on the assist spring with the FW's at or
> > comfortably under maximums (I prefer to set them at 10-15% below
maximum).
> >
>
> I would agree on this point at least in general. I prefer no
> assist springs myself, but I know there are lots of pros and
> cons and I probably havnt made my final judgement on their
> use.
>
>
> > ..... Might be a reason to keep the FW's a little lower on the
> > naturals though.  With the higher KR on the sharps you will have
> > corresponding higher FW's to accomodate weaker force leverage.  So you
might
> > consider keeping the sharps at FW maximum and allowing the naturals to
come
> > in a bit lower.
> >
> > David Love
>
> Hmmm.. I will think about this. Thanks for the fine words of
> advice David.
>
>
> --
> Richard Brekne
> RPT, N.P.T.F.
> Bergen, Norway
> mailto:rbrekne@broadpark.no