Loose Plate bolts = ?Tuning stability

[Joe & Penny Goss]

Good tidings all,
Just thought of a reason that the Yamaha piano might be going south. Are
they moving the piano?
Once saw a demo of how lifting the left side of a piano 1/2 inch untuned
the bass notes.
Joe Goss  On the level for sure O:)


----------
> From: Conrad Hoffsommer <hoffsoco@martin.luther.edu>
> To: pianotech@ptg.org
> Cc: hoffsoco@martin.luther.edu
> Subject: Re: Loose Plate bolts = ?
> Date: Monday, August 31, 1998 6:27 AM
> 
> Ron, you old ---> 
> 
> > Incoming!!
> 
>  Yup...
> 
> > In the twenty - plus years I've been in this business, I haven't ONCE
made a
> > definite correlation between tuning instability and loose plate bolts,
let
> > alone strings needing tapped down on bridges (but we can save that one
for
> > round two). 
> 
> You lucky, lucky guy!!  Worst case in my records was a new
> studio console built in DeKalb. Someone else had done the 
> warranty tuning, and I was third tech to look at it.
> 
> 8va above treble strut all over the place. As I was tuning it, I
> noticed a definite gap between the screw and the plate on two of
> the under pressure bar plate screws. Called to OK the work,
>   let down tension, tightened screws (as much as 1 1/2 turns), refit
> strings to hammers, etc.
> 
> 15 yrs later,it's more stable than any of the others of that make 
> which I service.
> 
> > What I'm more interested in
> > here, is a real world physics explanation of how this is possible.
> 
> I figger that section of pinblock was not fit real well, either, and
> the thing was just swinging in the breeze. (right strings were worse 
> than left) ....vector forces of angles of pressure bar, pin angle,
etc...?
> 
> Conrad
> 
> --
> Conrad Hoffsommer - Designing and testing virtual flamesuits since 1993
> 
>