Action compliance (was Re: Heavy Hammers)

Phillip Ford fordpiano@earthlink.net
Thu, 25 Sep 2003 09:42:39 -0700 (GMT-07:00)


>David Love wrote:
> > As pianists we know
> > that beyond ff, many pianos probably don't produce any more sound.  The
> > board seems to reach a point where it simply cannot put out anything more
> > without the tone becoming distorted--it becomes just more noise.
>
>Now I'm getting into an area I've not actually tested, but.... I think the
>distortion heard at this point is coming from a hammer gone out of control.
>As you approach action saturation the motion of the hammer becomes
>increasingly erratic -- it ends up flopping all over the place. This can
>easily be seen using high-speed photography to slow down the hammer's
>motion so it can be studied in slow motion.
>
>Del

Is the erratic hammer motion all from shank flexing?  Or is some of it 
coming from center pin bending or bushing compliance?  I've often wondered 
how we ended up with such tiny center pins.  Larger pins and bushings would 
seem to have less compliance.

Phil Ford



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