i have a 1989 Petrof III and I would like to "compact" the keyboard, meaning I want to feel more resistance in the key dip and especially a greater return weight of the key.
Furthermore, it is currently not very well regulated: it rebounds poorly, and I feel very little (almost nothing) of the pusher under the roller and its returning to position.
In general, I would like to know what to regulate to increase the sensation of return weight and dip.
Thanks to everyone who wants to help me and especially to Maestro Ferrarelli for the initiative and his precious videos.
As for me, I believe we should wait for the intervention of Pianoexpert who is currently away... In the meantime, whoever wants to step up...
In my opinion, trying to increase the return weight is fine; it is not equally logical to try to increase the let-off weight, usually one seeks a low let-off weight with a good return weight. The fact that you feel little return weight could indeed be a problem of friction preventing the key from returning freely. It could be many things, even tuners might be able to tell you a few things, but without checking the action on site, I see it as being very difficult.
Pianoexpert is out....but he responds. Friction, friction, friction!!!!! Welcome. You have a "lazy" piano and you are "suffering" (so to speak). You need to check the action pins. It takes an expert.....I mean an "expert". (It is not easy to replace the center pins "properly"!!!!)
The Petrof is a very beautiful piano. I have owned two. Some have slight mechanical defects, those that did not use Renner actions, but the general design is excellent.
i have already thought about calling a technician and I have already explained the situation to him; he will come in about a month, and since he has to regulate everything from scratch, I thought I would explore the world within it a little bit.
The piano which has Renner action potentially has a wonderful sound. I purchased it recently and it needs to be restored, both for voicing and regulation.
i would like to understand a bit more, however: for example, I noticed that by raising the let-off, the keyboard gains body but then seems to sound a little softer; I believe it is because I am reducing the hammer-string distance which is currently at 4.4 mm, whereas before it was at 4.6/7.
I am open to all possible advice.
Thank you all
Vincenzo
Ps: thank you for your videos; I have been trying to beg for "news" regarding piano mechanics for a very long time, and the technicians I deal with are very reluctant to give me even generic information....your videos were a wonderful bolt from the blue.
I will try to give you an answer while waiting for the Maestro.
In an upright piano, the hammer-string distance should not be adjusted by acting on the pilot. The latter (see tutorial) must be adjusted so that there is no play with the jack. Furthermore, the action must not rest on the pilot. By raising the pilot beyond the optimal adjustment, you lift the key action, raising the hammer and bringing it closer to the string. This is why you feel more weight.
I take the liberty, dear Lorenzo, to correct one of your statements that might cause confusion. When the wippen is too high in the vertical position, the escapement lever cannot return under the hammer cap. The "signal" of a good regulation lies in checking this "free engagement." Be careful, however; it takes some experience and sensitivity to understand the correct and precise regulation.
The distance between the hammer and the string should not be regulated on the wippen, but rather by moving the hammer rest rail. Then, one will proceed to the regulation of the wippens as described. Careful, though; if the hammers were very shaved down (an unsound choice), one would be forced to bring the rail too far forward, thus distorting the "geometry" of the action.
i am happy to inform you that thanks to your advice the action of the upright piano is much better, the previous owner had shortened the wippens so he had moved the hammers too far from the strings.
Two problems have now arisen for me:
1) some keys in the fifth octave have a less intense sound than the others. (in general the piano needs accurate tuning)
2) in particular I noticed that there are two hammers that rise a bit more than the others and that press against the string, choking the sound; I managed to move it away a little by acting on the escapement button and the riser (I want to specify that in the resting position they are all at the same height), but it still sounds softer than the others.
What do you think the problem is? What should I work on (while waiting for the technician)?
what you have done is fine. We need to see the condition of the hammers. In the treble notes, their "head," meaning the apex, has a fundamental function. if they turn out to be not very compact and/or rounded and softened by an incorrect shaving, one can try to stretch them and soak them to re-voice them....but they would need to be seen. The sound becomes dull even if they are heavily marked, and the grooves, at the moment of impact, deflect and muffle, almost dampening the hammer strike.
I also have a question: I have a rather old Petrof upright (it's from '76 and I have been the sole owner). It seems to me - and my teacher confirms - that the key dip weight is not uniform. What should I insist the technician checks the next time they come for tuning? In any case, is there any minor adjustment that can be made while I wait?
I have owned several Petrof uprights and grands. The Petrof is an excellent piano in terms of sound design, but the actions are a bit less good, at least those made in Czechoslovakia. They have improved greatly now. Generally, when significant discontinuities are felt, one should never compensate with weights and/or spring reinforcement. This would only increase the sensation of friction. Now, even though some of us argue that for studying it is necessary to have a "robust" keyboard, connecting this concept with the principles of piano technique (a connection that, as an absolute novelty, is very close to my heart), I must state that with this concept one is on the wrong path. The guiding Principle must be the standard that major brands like Steinway and others strive to achieve: Letdown approximately 47-50; repetition approximately 22-27. Any other condition presenting an excessive imbalance between letdown weight and repetition weight shows the presence of excessive friction that prevents the action from functioning naturally.
I am convinced that a pianist, even a student, must grow technically with a keyboard that works well and not with instruments falsified by intentional weighting to "build muscle." If this were correct, a child, fortunate owner of a Steinway grand, would develop their technical growth poorly.
The path to follow in your case is only to check the frictions and, if necessary, eliminate the excessive ones with competence. Then one must proceed to the perfect regulation of the action, including the correct let-off suggested by the Manufacturer. Good tuning and hammer voicing will make the instrument truly efficient. A skilled technician is needed to analyze everything and propose solutions. Good luck with your work and your studies.
I had the mechanical regulation done about two months ago, along with the tuning (and shaving of the hammers, unfortunately necessary) and the string tuning. On that occasion, the technician also "lightened" the keyboard. I was perfectly satisfied with the result, especially because the piano recovered its original sound. The problem cropped up after two months of intensive use, along with some small issues that I had corrected yesterday. The next tuning is scheduled for spring, which means I will ask him to check the frictions. Thanks for the response.
What does "lightened the keyboard" mean? Be careful not to add lead weights, as it could modify the inertia and decrease the return weight too much. Forgive me for intervening, but perhaps the skilled technician surely evaluated everything.... just as they would have taken care to respect the shape of the hammers, more rounded in the bass and more "pointed" in the treble.
He simply made it less "hard" by adjusting the mechanics, he didn't really add anything. In fact, immediately afterward I was playing much better. And yes, the shaving was done well, he seems competent to me.
It's just that my poor piano has been neglected for several years and so it still has some settling issues (it's not due to lack of interest, it's just that I simply couldn't afford it before).
You won't believe it, but the piano is performing quite a bit better now; I managed to regulate it while waiting for the technician. The hammers are at a distance of 4.6 cm from the strings and the let-off is 10.1 mm.
I have adjusted more than just the hammer-string distance: the escapement and the cylinders for the rebound that the hammers must perform.
However, there is a problem with 2 keys that are acting up: despite being identical to the others in terms of regulation, they do not resonate at 2/5 of the key stroke like the others, but instead need 1 or 2 more millimeters; consequently, they cause quite a nuisance during tremolos and trills. I also hear something knocking sometimes?
I await your expert opinion.
thanks to everyone
vincenzo
(I feel the keyboard is faster than before; previously the hammers were further from the strings... is this a good or a bad thing?)
