Italian technicians are against, at least most of them, tapping the ankles to insert them. Americans, on the other hand, say that both must be done: tapping causes a beneficial friction in the wood, which, by overheating, embraces the ankle so to speak. The micro-threading rubs the walls and subsequently the act of turning them distributes and compacts the "scraped" part. In short, they are very much in favor of a mixed technique. I, too, am for this choice.
P.S. the capstan is not threaded, it is the ankle that is micro-threaded.
P.P.S. in the grand piano, it is appropriate to support the capstan with a special support to avoid damage.
Thank you Maestro for the precious advice, I felt that playing loudly was not the way, also because the hammers to which I applied the "treatment" are located in areas where the soundboard ends.
Italian technicians are against, at least most of them, striking the ankles to insert them. Americans, on the other hand, say that both must be done: striking causes a beneficial friction in the wood, which, by overheating, embraces the ankle so to speak. The micro-threading rubs the walls and subsequently the act of turning them distributes and compacts the "scraped" part. In short, they are very much in favor of a mixed technique. I, too, am for this choice.
P.S. the key lever is not threaded, it is the ankle that is micro-threaded.
P.P.S. in the grand piano, it is appropriate to support the key lever with a special support to avoid damage.
That is, you remove the action and place supports between the lower part of the key lever and the soundboard? This discussion is interesting :) :)
Exactly so. Now, if one changes a string, this is not indispensable, but in the case of a total replacement or an entire section, it is advisable to use the support.
The video Lorenzo found is interesting; I prefer to strike less with the ankles and twist more.
Let's not forget that the soundboard is made of high-quality woods, sometimes of different essences glued with cross-grain, which must perpetually withstand a load exceeding 17 tons!
Ok. I posted the video only to show the tool that protects the soundboard! I discovered it by chance!
I also think the guy in the video is exaggerating a bit. I have never dared to perform similar operations on a piano, but I know enough about wood. If I'm not mistaken, the soundboards of antique pianos were made of a single board and, in that case, an operation like this would easily crack it! :o
But I don't think so. One must consider that the soundboard is much more fragile (if one can speak of "fragility," in case of... danger of cracking) when it is still without braces. As the braces are positioned, a series of compensatory forces is created that strengthens the structure. Just as one should consider that now the soundboard is not made only of wood or woods... but also of steel. After all, in each hole... the wood is replaced by a steel pin!!!!! What do you think? It is nonetheless appropriate to use the support to avoid vibrations, transmitted by steel more rapidly than by wood.
Of course Paolo, as you say, the pins tend to assimilate a bit of the wood to the steel.
I also think that the horizontal tension produced by the hitchpin plate further stiffens the soundboard, making it less vulnerable to vertical stresses (insertion of pins).
To assert this is very difficult. If we examine all the forces and torsions that occur with strings under tension, it would take a lot of time and patience. One never finishes discovering new stresses. In the piano, there is a great balance in the presence of great forces. And such forces can change in the presence of different conditions.
