i would like to ask Paolo, and anyone else who wishes to participate, if on the tail it is possible to perceive on the keyboard the moment when the parameter hammer "grips" the hammer, creating a tactile sensation.
At the moment they are regulated to "stop" at about 12 mm from the string, and to have this distance, the tail of the hammer must be gripped at the tip by the upper part of the parameter hammer.
In case this is anomalous, what could the problem be due to? Are perhaps 12 mm too little? What could be the maximum "grip" distance without compromising the performance of the action?
I have seen the tutorials and I imagine that the parameter hammer must also act as a shock absorber by gripping on the soft felted part and not too high up... but this way it seems impossible for me to maintain 12 mm.
There must not be a small difference between the drop point and the maximum escapement point. 12-15 mm is fine. The important thing is to check the level of the escapement lever relative to the repetition lever and relative to the inner part of the wooden core of the hammer, otherwise the hammer jams before rising freely and the repetition is compromised.
The difference is not much, especially on the bass. Maybe it's better to increase it a little bit..
What do you say instead about the perception of the parade on the key? Do you say it could be the riser? Later or tomorrow I will post a photo so you can tell me.
all the pushers appear to be perfectly aligned with a notch present on the repetition lever, is that correct? at rest there is a very slight friction with the roller..
In my opinion, the repetition lever is too low compared to the repetition spring. That slight friction you feel also takes into account the force of the spring. If the lever is too low and the spring is too heavily tensioned (limit situation), letting go of the key gently results in a small thud felt under the finger. This must not happen. The hammer regulator is not involved. I believe this is what you mean.
In my opinion, the repetition lever is too low compared to the repetition spring. That slight friction you feel also takes into account the force of the spring. If the lever is too low and the spring is too heavily tensioned (limit situation), when releasing the key gently, one feels a small click under the finger. This must not happen. The paramhammer is not involved. I believe this is what you mean.
It is my opinion—but not mine alone, and it finds wide support in technical literature—that the pusher should be free to retract under the roller with the hammer at rest, but at the same time, the weight of the hammer should not rest solely on the repetition spring; therefore, when pushing the pusher out with the finger, one should feel a slight friction and simultaneously be able to observe an oscillation of the hammer downwards (when we push the pusher out with the finger) and towards the other side when we allow the pusher to return to rest.
Literature states that the height of the repetition lever relative to the pusher should be 0.1, 0.2, or 0.3 mm, but who measures it? I believe no one. One must calculate that that gap corresponds to a hammer oscillation of 1.5 to 2 mm in length (which can be easily evaluated by comparing the oscillating hammer to its neighbors).
Exaggerating this difference means being unable to find the alignment of the hammers at rest and having lost motion, too much play.
Obviously, the verification must be done after having unloaded the springs, if they are too heavily tensioned as in this case.
In fact, that is exactly how it is, Giovanni !!!!!!! The Americans, once the height of the repetition lever and the spring tension have been regulated, perform a final check they call "rocking the fly," meaning with their finger they push on the tip of the repetition lever and must feel a slight friction as it slips under the roller. Naturally, if the resistance is too much, the repetition lever does not return perfectly. Then either the spring is weak (check the clear upward movement of the hammer without jumping) or the repetition lever is leveled exactly with the repetition lever or even above it. It is only right that one cannot find the alignment of the hammers at rest when the difference in level between the two elements is excessive!
even if we tell ourselves otherwise, the right balances require a lot of sensitivity from the technician....and a lot of patience...but always with awareness, there is no sense in trying "just because"
It is not a matter of two hours, one morning or one day...But of repeated checks and tests until the maximum result is achieved. Even if the adjustments are the same.
Pianists should also understand that sometimes the "lever" (key length) limits this result, except perhaps in grand pianos of great craftsmanship and from other times, and therefore one cannot hope to obtain on a grand piano what is obtained on a concert grand...at a certain point, one must recognize not only the limits of the technician but also the limits of the instrument.
A correct mechanics-sound relationship and proper sizing of components (correct masses, correct weights and therefore correct design frictions) are the icing on the cake, together with that quarter turn of a screw forward or backward that a good mechanical technician is able to impart, in defiance of all theories, not to change a measurement, but the result of a good regulation.
Higher-level thinking! I quote these concepts that Giovanni argues well. The purpose of this Forum, in fact, is also to elevate the state of consciousness regarding what one's own instrument is and/or "the instrument we find ourselves in front of". It is very difficult to make people understand where the limit of the instrument lies, where that of the technician lies, and where that of the pianist lies. Let's say that a good pianist who understands that they must "rely" on the instrument and not "challenge" it is already on the right track. If they are then assisted and advised by a competent technician, who knows how to properly understand their needs and also knows how to satisfy them, then the three levels will rise in parallel and ever higher.
Thanks to Paolo and Giovanni who supported me on many occasions.
I clearly agree that a baby grand cannot become a grand piano, but sometimes it happens that the initial issues are not given proper attention, especially if the pianist is not a professional or is a student.
It is also true that fine regulation takes different amounts of time and a single session of intervention is not enough, and many times the pianist, inexperienced in mechanics, also has difficulty identifying the problem.
Precisely for this reason, after selling off a baby grand for problems that were certainly solvable, I decided to perform some adjustments myself.
Returning to the subject of the post, I believe that the photos I attached are a bit misleading and make the riser look too low. Tomorrow I will attach another photo from a different angle.
First of all, the springs should be unloaded to obtain uniform tension across the entire keyboard, so that the hammer's ascent occurs without uncertainty but also without bouncing. When everything is correct, the pusher retracts under the roller upon key release, without the key necessarily having returned to rest, but still ready for repetition, without producing return noises mainly due to an overly violent impulse caused by excessive charge. The bass notes will be slower in their upward motion, and the treble notes faster due to the lighter weight.
The correct distance between the hammer and the string, in relation to the correct let-off, allows the pusher to exit freely but without moving too far from the roller and prevents the upright from rising too much. Only a sliver of light will be observed between the roller and the pusher when the key is fully depressed, which is enough to facilitate its return motion.
Correct let-off is that which allows us to observe, by pressing the key slowly and letting the hammer fall into the second escapement position, a hint of the hammer's own ascent after the fall, as the key reaches the end of its travel... the hammer's fall will occur smoothly, without jerking. The key bushing must be of medium density, not deformable by the normal gesture of playing forte or fortissimo, such that it feels stable.
The paper slips used for adjusting the let-off should be as few as possible, with the thinnest ones on top, to avoid an "accordion effect" when the key is pressed.
Trying to lift the wippen by just a tiny bit (with the key at rest), it does not go under the roller. I believe therefore that they are already fine: the alignment of the hammers at rest is possible and the slight hammer oscillation is visible if I move the wippen in and out with my finger.
Background, mc distance and after-blow already adjusted (the solution for thickness under the key suggested by giovannig for a precise after-blow is excellent)
I therefore slightly lowered the springs as suggested and brought the hammer regulating rails to about 15 mm and the situation improves significantly; even the sound is clearer and cleaner.. incredible, it seems as if it has just been tuned.. am I imagining things?
The hammer rails are not a problem, 12 or 15 mm makes no difference... it is an indicative measurement that depends on how much felt is on top of the hammer head and also depends on whether you have verified it with the action installed playing piano, forte, or fortissimo.
2 mm more or less of felt, depending on how much felt was lost during the hammer preparation, can distort this measurement relative to the string. what must be observed at the bench is that in repetition, the tail should be 1/3 inside and 2/3 outside relative to the hammer rail.
the important thing is that the pusher is free to return on its own under the roller and that when you press the lever to make it come out, a minimal friction is felt.
In any case, the subject is "the repetition lever" not the pusher. By acting on its adjustment screw, it is correct to say that you have lowered the repetition lever and not raised the pusher. The pusher only has adjustment forward or backward relative to the notch for alignment with the roller, while it is fixed in height.
Anyway, from the photo I see a configuration that is correct, meaning they are all slightly lower than the surface of the repetition lever (which is the part of the repetition lever with the window and the notch, to be clear).
12 or 15 mm makes no difference clearly, does it also depend on the hammer tail? In my case, the tails of these hammers, which are new even if original, were gripped by the upper part of the hammer rest... right where the felt ends.. I believe this was the problem. I checked the mechanical setting while playing f and then adjusted it at the bench.. on ff the distance definitely increases and on mf it decreases.
1/3 inside and 2/3 outside.. I haven't measured this but I believe it is approximately so.
the pusher is free to retract and by pressing on the lever to make it come out, the hammer drops slightly. So there is a minimum amount of friction. I believe the roller rests on the repetition lever but also on the upright due to the small step on the skin created by its compression.
the subject is the repetition lever, clearly (the upright is fixed in height but... it magically rises and falls)
yes, with this photo it is seen better, the first one I had posted made the upright appear too low as correctly indicated by Paolo.
Here, there is a book by an American author that at this point writes something like: "now that you have verified that everything works as described, you can turn the screw another 1/4 turn counterclockwise"...
what is it for... it's to maintain a certain margin specifically on issues of climate, felt compression, depressions etc. and not touch the mechanics again for another 30 years...
in the paramers, same story. If you had left them at 12 mm, you wouldn't have had to touch them anymore; as hammers are replaced, the groove in the felt will increase and therefore so will the distance.
Same story regarding the escapements and everything else that can be compensated for by wear and tear....this is a reasoning one makes because generally, the average pianist calls the technician once every 10 years if all goes well.
we talked at length about the importance of mm and now we want to tighten the screw a quarter turn more? and until the compensation has occurred, what do I do? Do I plug my ears and play with gloves on?
Maybe it's because I do something else entirely than being a pianist, even though I have a conservatory diploma, but the technician/tuner comes to me at least twice a year...
Quarter turns do not modify the measurements in mm, but they are often the deciding factor between an optimal and a poor adjustment. At the end of the work, the mechanical technician feels with their fingers on the key whether it is necessary or not.
An escapement set at 2 mm after a possible quarter turn of the button remains at 2 mm, but it can totally change the sensation felt during the click or the ability to execute a pianissimo or to pierce the note...
