Hi Issac, At 08:56 PM 5/23/2003 +0200, you wrote: >Hello Roger, > >I like a bit of clearing on the bedding aurally too, I listen for >knock on the front rail, pushing on it with my thumb to compare the >noise, I understand we can listen to an open or too compressed balance >rail, but I am not sure I understand when you say that you aim for the >same tone - You mean the same tone all along each rail, or a tone that >tells the quality of the weight on the frame ? The same kind of tonal knock at each glide as you thump the down on the key buttons. >Or is it to be done without the keys ? I only bed frames with the keys in. There is a lot of lead in those keys. For the most accurate and stable job, it's the only way to fly in my book. >I've been a long time confusing knocks that came from the back rail, >very often when the regulating screws are screwed a lot, and the >knocking of a correctly bedded balance rail (that knocks evenly and >easily even if there is a lot of pressure, assuming it is evenly >distributed. > >Are the intermediate screws (hidden) checked for knocking in the same >"tone" idea ? Yes. It is very important that these be done. The reason that they are there is because there are 4-5 leads in each of the bass keys. This really loads up that balance rail in this area. The top treble has just as many keys as the bass, but there is no need for hidden glide, since there is hardly any lead in the top keys. The hidden glides are in the bass and tenor sections. Remember this softwood frame has a spruce balance rail, with two thin maple strips that adds strength to hold the balance rail pins. It's also important to adjust these hidden glides with the correct tool. I have found more than a few butchered Regards Roger >thanks and Best regards. > > >Isaac OLEG > > >Isaac OLEG > >Entretien et reparation de pianos. > >PianoTech >17 rue de Choisy >94400 VITRY sur SEINE >FRANCE >tel : 033 01 47 18 06 98 >fax : 033 01 47 18 06 90 >cell: 06 60 42 58 77 > > > -----Message d'origine----- > > De : pianotech-bounces@ptg.org > > [mailto:pianotech-bounces@ptg.org]De la > > part de Roger Jolly > > Envoye : vendredi 23 mai 2003 02:52 > > A : Pianotech > > Objet : Re: No Power Yamaha revisited > > > > > > > > > > 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 > > > > PS I thought we covered the topic of hardwood and softwood > > rails, quite > > well in the Interactive Grand Regulation series. Gee that > > was 2 years > > ago. Tempus fugit. > > > > > > At 04:03 PM 5/22/2003 -0500, you wrote: > > >Hi Roger, > > > > > >But why won't Yamaha tell us how they do it? (See my > > previous post to > > >Richard.) > > > > > >Avery > > > > > >At 01:56 PM 05/22/03 -0600, you wrote: > > >>Hi Ric, > > >> A very soft flexible action frame, they move > > a lot. I bed > > >> these frames every time I tune a Yamaha grand. > > >>With practice it only takes about 3 or 4 minutes. The > > weight of the keys > > >>is more than enough to flex those frames, hence the change in dip. > > >>The design is such that the frame is is supposed to flex. > > >>Bin thar and bought the tee shirt. <G> > > >> > > >>Regards Roger > > >> > > >>At 06:12 PM 5/22/2003 +0200, you wrote: > > >>>Ok guys and gals... > > >>> > > >>>I gots to eat crow here... I think anyways. As it turns > > out I managed > > >>>to finnally solve the hammers bouncing all over the > > place thing by > > >>>turning up all the bed screws so that the key frame was > > solidly bedded > > >>>with the actuall wood of the balance rail a full 2 mm > > elevated over the > > >>>key bed. Huge increase in power, but this also caused an > > increase in > > >>>keydip to 10.5 mm (!) and forced a drop in blow to just above the > > >>>cushions... perhaps the shanks are about 2-3 mm off. However.... > > >>>absolutly no bouncing of neighboring hammers any more, > > and that feeling > > >>>of loosing power is gone. > > >>> > > >>>What I dont get is why the Balance Rail needs to be > > elevated so much. > > >>>And how are we supposed to determine the proper balance > > rail height to > > >>>begin with ? I was always told that glide bolts need to just make > > >>>contact with the key bed... not to lift the whole darn > > middle of the key > > >>>frame up. > > >>> > > >>>Explainations please ? > > >>> > > >>>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 > > >>> > > >>> > > >>>_______________________________________________ > > >>>pianotech list info: > > https://www.moypiano.com/resources/#archives > > >> > > >> > > >>_______________________________________________ > > >>pianotech list info: https://www.moypiano.com/resources/#archives > > > > > >_______________________________________________ > > >pianotech list info: https://www.moypiano.com/resources/#archives > > > > > > _______________________________________________ > > pianotech list info: https://www.moypiano.com/resources/#archives > > > >_______________________________________________ >pianotech list info: https://www.moypiano.com/resources/#archives
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