I have a few questions to ask: since I intend to replace the felt pads of the stilette (they are quite worn down), I wanted to know if any particular precautions need to be taken, what type of glue should be used, and if in general it is a type of work that can be done alone. And finally, I wanted to know if I can use a slightly larger diameter to increase the perception of the escapement under the fingers while playing.
I apologize to the technicians if perhaps I am approaching the problem incorrectly. Regards!
It is not a matter of perceiving a sharper escapement, but rather perceiving a certain fatigue of the pusher when exiting from under the knuckle that does not allow you to play pianissimo, or to perform agile passages naturally.... Do you need a work keyboard? Do not exaggerate the difference in this case.
To replace the knuckles, I recommend unscrewing the repetitions with the hammers in an alternating manner (first, third, fifth, etc.) and arranging them in the action with the knuckle facing upwards. Using a knife, score the glue of the leather flange on the right and left sides where the stiletto touches, and then use a small brush to apply alcohol into the incisions. Let it act for a few minutes, and then holding the stiletto in your hand, grip the knuckle with pliers and extract it slowly, oscillating it slightly if the glue is very hard and they do not come off easily.
Afterward, clean the glue residue with a file, and glue the new knuckle in the correct direction; sometimes it is necessary to lower the small wooden piece slightly to allow full contact between the stiletto and the knuckle through its engagement.
Once the new knuckle is inserted, you must clamp the stiletto and press the knuckle against the stiletto slightly so that excess glue overflows and everything adapts perfectly. This is also to compress the knuckle a little and stabilize it; otherwise, it will compress under the weight of the hammers, and it will be necessary to lift the repetitions several times over time.
Afterward, screw them back into the old position using the neighbors as a reference, then do all the even ones.
It is a job of patience; it is not difficult. You can also search on YouTube; knuckles in English are called "knuckles", so by searching for "grand piano knuckles replacement" you will certainly find something
You should measure their diameter in the non-flattened part from wear and order rollers of that size.
Keep in mind that once they are installed, you must perform all the mechanical adjustments; the position of the escapement lever relative to the roller and relative to the capstan is what gives you a good feel under your fingers when playing.
The let-off and repetition (spring) are fundamental.
In reality, everything is fundamental in regulation, but I would have to write you a book...
Dear Boristarpini, all of us geeks are waiting for exactly that, for some kind soul to write a good manual on piano maintenance and regulation, come on, give us this wonderful gift!!
