No Power Yamaha revisited

[Farrell]

----- Original Message ----- 
From: "Richard Brekne" <Richard.Brekne@grieg.uib.no>
To: "Pianotech" <pianotech@ptg.org>
Sent: Friday, May 23, 2003 6:49 AM
Subject: Re: No Power Yamaha revisited


> Thanks muchly Roger...
> 
> seems to be the description that makes the most sense so far. Very roughly
> then, adjust the glide bolts so that they all are in contact with the bed, AND
> all lift the balance rail to the point that the Front Rail is just a nats butt
> away from being lifted as well...
> 
> Key height and the rest is set afterwards.
> 
> Correcto ?
> 
> 
> Roger Jolly wrote:
> 
> > Hi Avery & Ric,
> >                           I have a good minds eye view, of what is going
> > on, but I'm not so sure I can explain it well.   But here goes.  (Send me a
> > deluxe flame suit Conrad).
> >
> > If you have the bolts just touching, there is no compression force acting
> > on the balance rail.  With rapid forceful playing, there is a small amount
> > of bounce taking place at the balance rail, robbing the action of a lot of
> > energy.  It gets dissipated within the frame.
> > Jack the bolts a little further down,  you start to bow the cross
> > struts.  and putting some compression into the rail. , and firmly seating
> > it to the bed.   At the Yamaha Technical Academy, they spend a good deal of
> > time teaching you how to tune these rails in aurally.  takes more than a
> > little practice to get optimum results.
> > The front rail is done first, by tapping on the front rail with a kind of
> > 45 degree blow, to the leading edge of the rail.  (You can hear better than
> > the traditional method of holding a key down and thumping on the key, the
> > front rail punching absorbs a lot of noise,) Then the bolts are adjusted so
> > the front rail just starts to lift, then back off about 1/4 turn.  Next
> > step is get all the glides bedded so the tone is the same when lifting up
> > on the hammer rail, and thumping down on the balance rail.
> >
> > The closest analogy I can think of,  is like string bearing across the
> > bridge.  Too much bearing and a loss of tone, too little loss of tone.
> >
> > Now I will crawl under my rock and smile.
> >
> > Regards Roger
> >
> >
> 
> Cheers
> RicB
> 
> --
> Richard Brekne
> RPT, N.P.T.F.
> UiB, Bergen, Norway
> mailto:rbrekne@broadpark.no
> http://home.broadpark.no/~rbrekne/ricmain.html
> http://www.hf.uib.no/grieg/personer/cv_RB.html
> 
>