Scruffing -was - Over-Strike vs Under-Strike

[Steve Blasyak]

Hey Now,

Regarding the text book definition of the word scruff or scruffing. I think
we all got the intent/meaning of the word in the context of the original
post. Thus I think the use of the word served its purpose, did it not? 

With all this discussion about scruffing vs scuffing and over strike vs
under strike yada yada, I have a question. I know there is a formula or
method to determine the correct hammer bore on a grand. I believe it is the
distance from the key bed to the strings minus the distance from the key
bed the center pin on the hammer flange, or something like that.
Corrections will be in the mail if I'm wrong I'm sure. To prevent over
strike and or under strike, what is the correct way to determine the hammer
bore on an upright? 

Pura Vida

Steve 


> [Original Message]
> From: Bob Hull <hullfam5 at yahoo.com>
> To: Pianotech List <pianotech at ptg.org>
> Date: 11/25/2006 5:19:18 PM
> Subject: Re: Scruffing -was - Over-Strike vs Under-Strike
>
> I agree: "Scuffing" is a more accurate word than
> "scruff" to describe a sliding blow that isn't able to
> rebound directly in the same plane of motion in which
> it approached its target.  Like scuffing your shoes;
> Scraping, abrading, grazing. 
>
> Wouldn't this type of blow also casue the hammer to
> stay on the string longer and affect various partial
> strengths?  Of course, not only overstriking results
> in scuffing but other things such as loose pinning,
> action rails that are not perpendicular, poorly
> anchored hammer flanges, warped hammer shanks, and the
> list goes on.  
>
> All of these add to inefficiency and lack of control.
> Faster wear of hammers, and perhaps wear of bushings
> could result from this type of hammer boring.  
>
> Boring that creates overstriking so the hammer shank
> can whip backwards does not take into account soft
> blows that have less whipping or bending of the shank.
>
> I have changed overstriking hammers in action rebuilds
> to 90 degrees, both in uprights and grands, (adjusting
> for strike points) with improved results.
>
> Bob Hull
>
>  John Delacour <JD at Pianomaker.co.uk> wrote:
>
> > At 6:30 pm -0500 25/11/06, Sid Blum wrote:
> > 
> > >I've enjoying and learning from this discussion 
> > but got curious and 
> > >thought to share this:
> > >
> > >http://dictionary.reference.com/browse/scruff
> > 
> > Yes.  I can find no definition of 'scruff' that
> > remotely indicates 
> > the phenomenon under discussion.  Perhaps they mean
> > 'scuff', but even 
> > that would be far-fetched.  What happens is that the
> > nose of the 
> > hammer strokes the string or slides along it, as
> > happens by design, 
> > and to a greater extent, in the Viennese grand
> > action.
> > 
> > JD
> > 
> > 
>
>
>
>  
>
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