Isaac OLEG wrote: > But, Richard, that is felt in the tone and in the key if the bedding > is not firm enough. Yes... I know this Issac... its what I have been questioning about for a while now. The problem was not the firmness in the bedding, but the fact that the glide bolts werent forcing the balance rail up high enough, evidently anyways. You refer to this as putting the action under compression I think, yet I find no exacting proceedure for setting this anywhere. > When playing hard the back of the frame tend to lift up, may be you > may check the holding of the rail there. I did all this many times... and it has been good tho the bedding was lower. > If too much pressure on the screws, the tone became more "woody" and > straight, the more power that you have is also coming from the letoff > which is nearer, but mostly (I believe) because the hammer center pin > is then higher, and if the hammers are less tall than originally this > correct the geometry of the hammer towards the strings a little. The increase in power did not come from any change in letoff. For the first.. there was no uniform change, the power increase more than likely came because the force that was put into the key is no longer getting dissipated in all the flexing that was going on. There may have been a slight change in blow distance, I didnt check because the increase in aftertouch needed paying attention to then and there, so I just lowered the line. But if so it was not very much. How much the hammer centers rose is another thing. On the C7 I have I can pay closer attention to that. I doubt tho that the slight change in hammer angle this would cause would account for this increase in power. That being said, the "feel" of the action under the differeing circumstances seems to conform nicely to your first sentence. If I screw them up to high I did get a woody character from the tone... I presumed this was because the action itself was contributing to the sound more. Another point was that I had to re-regulate back checks, and checking could not be so high as before. Forced me down to 15 mm from the strings. Any higher tho and the checks would hang on the tails on hard blows. > For what is worth, the point by point method as explained by Andre > works every time - but you are supposed to know what key height is the > norm for the model, it helps a lot to have an even ratio between > blacks and whites, and put the keys in their optimum position for > regulation. > Thats the real trick tho isnt it.... ? I mean key height is suddenly dependant on two things... balance pin punchings, and balance rail height. How are you to determine one without knowing the other ? And like I say, I have not run into any specifics about setting balance rail height before... only bedding proceedures that state the glide bolts need only make firm (all of them) contact with the keybed. I would really appreciate seeing Andres point by point on this again... I remember a post he wrote about glide bolts not so long ago.. but I dont remember this being a point by point proceedure. If you have that please post it :) > > Thanks for the feedback. > > BTW I bed the keybed of a C6 today, with the regulating screws a good > 2-3 mm lower, the key height was 64.5 mm, allowing for 10 mm dip, > measured with the nice brown 9.95 mm dip block from Yamaha. > > The Yamaha (-French) explanation about the use of this tool (and why > it is not really exactly 10 mm) is that it is easier to feel the block > while it is a little lower than the adjacent keys, we aim for the same > sensation than the little play in the jack's windows. I like these > over simplified approaches ! > > Best greetings > > 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 Richard Brekne > > Envoye : jeudi 22 mai 2003 18:12 > > A : Pianotech > > Objet : Re: No Power Yamaha revisited > > > > > > 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 -- 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
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