C88 Hammer Position

[Tony Caught]

Hi Terry & John

Thanks John, yes I am referring to speaking length of string and portions
thereof. (did you like that ?)

When referring to the hammer strike point I prefer to talk in divisions of
the speaking length as it is where the hammer hits the string that denotes
which partials will be promoted and which ones will be suppressed.

In most old pianos (I think) the strike line was a straight line.

The bass from A0 could be at 1/7 to 1/9 of the speaking length, depending on
the tone that that particular designer wanted. (American pianos were mostly
1/8)

Even so, tis the treble we are talking about.

In those days of past it was acceptable to set the strike point at 1/8th on
C88 and 1/8th on A0 then draw a straight line, then place your bridge at
7/8th the length below and the upper bridge or aliquot thingee at 1/8th
above.  This is in design and casting frame and fitting bridges etc.)  Now
the action is fitted in relation to the hammer hitting the strike point and
every part has exactly the same travel as the keyboard is parallel to the
strike line.  Then you find that you want a brighter sound in the upper
treble, so you bend the hammer shanks up to find that nice sweet point.

Problem is that if you set the upper point (C88) of the strike line too
high, say at 1/8", it will sound right on the top 4 to 6 notes, a little off
on the 6 notes below then come good again.  Its the original balance you
want, or an improvement on the original.

Measure the strike point on A0 then on C6  (strings should be shiny from the
hammers, pick the centre of the shine to denote strike point) tie a string
on strike point of A0, pull string firm at C88, align string on C6, see
where string is on C88 and set that point as your strike line.  If on C88 it
is 1/8th, then bend shanks to raise the strike point. If on C88 it is [1/8"]
just fit the hammers to the strike line as is.

Hope this reads clearer than it sounds.

Tony



----- Original Message -----
From: "Farrell" <mfarrel2@tampabay.rr.com>
To: <pianotech@ptg.org>
Sent: Friday, November 09, 2001 10:01 PM
Subject: Re: C88 Hammer Position


> Hi Tony. Thanks for the thoughts. I need a little clarification though.
Like
> my high school chemistry teacher used to say "units, units, units, where
are
> your units"! My post referred to a C88 strike point 1/8-inch below the top
> termination point. I strongly suspect your numbers in your post reflect
> ratios of strike point below top termination to total speaking length? If
> that is true, then the 1/8-inch that Wally suggested for C88 would be
> consistent with your apparent recommendation of a 1:16 ratio (speaking
> length is 2 inches).
>
> I realize the "1/8 on A0" is pretty much a dead give-away that you are
using
> ratios (where do I find hammer shanks 14 inches long???), but please
clarify
> so that I know you have not possibly mixed units. Thanks
>
> Terry Farrell
>
> ----- Original Message -----
> From: "Tony Caught" <caute@optusnet.com.au>
> To: <pianotech@ptg.org>
> Sent: Friday, November 09, 2001 6:09 AM
> Subject: Re: C88 Hammer Position
>
>
> > Hi Terry,
> >
> > Long time no write. Actually 1/16 is more like it. some like it even
> higher
> > but the top notes from C88 at 1/16 to C76 at 1/10 then to F69 at 1/8
> should
> > sound about right.
> > Try just marking the strings at 1/8 on A0 and C88 on 1/16 and see where
> the
> > top treble lays when measured.  If you set C88 at 1/8, you can always
heat
> > the and bend the shanks and raise the hammer strike point to find the
> sweet
> > spot for your self.
> >
> > Regards
> >
> > Tony Caught
> >
> >
> > ----- Original Message -----
> > From: "Farrell" <mfarrel2@tampabay.rr.com>
> > To: <pianotech@ptg.org>
> > Sent: Friday, November 09, 2001 11:02 AM
> > Subject: C88 Hammer Position
> >
> >
> > > Hi List. I am installing a new action in an old upright. I need to
> > determine
> > > the best position for hammer height on C88. On a grand, I have the
> luxury
> > of
> > > moving the action in and out to find best sound. How is this best done
> on
> > an
> > > upright? Is there a general optimal position? Wally Brooks says 1/8"
> down
> > > from top termination. I realize he is quite knowledgable - and I will
> > follow
> > > his advice if I get no further input, but I wondered if there were any
> > > differing opinions. The speaking length on C88 is 50.5 mm. Or should I
> put
> > a
> > > hammer on C88 a bit on the low side and just lift the action up and
down
> > > trying to find a best height (seems like things could get out of
hand -
> so
> > > to speak). Thanks
> > >
> > > Terry Farrell
> > >
> > >
> >
>