Good morning, I am new to the forum, my name is Lorenzo and I have a problem that has been troubling me for a long time.
I have a W. Krauser upright piano (about 15 years old) whose keys tend to remain depressed after being pressed, especially during repetition.
A short time ago I had a tuner come over who, in addition to adjusting the regulation (in fact, the keys had a bit of play), tried to do everything possible to avoid this phenomenon, which however reappeared after playing for a few hours a few days later.
Opening the piano, I noticed that the escapement lever struggles to return to its initial position; it is as if it gets stuck halfway through its stroke.
After "escaping" from the hammer, at the moment the finger releases the key, the escapement lever tends to return under the hammer, but at a certain point it gets stuck and the hammer does not return to its initial position. Consequently, the key remains "pressed".
What can be done? Is it a "congenital" defect of the piano or can something be done? 😟
Thank you all for the answers!
P
Pianotuning
Reply 2 by Pianotuning
Hi,
if the capstans have already been adjusted,
it could be that the action lever springs have lost their tension and therefore it is better to replace them,
or check the center pin of the lever and then the jack pin.
it can depend on the center pivot of the escapement upright, or on the front Kasimir gaskets or key center gaskets, or on the spoon that lifts the damper lever. The upright must have a minimum amount of play to return under the nut. Also check the spring.
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Biancoenero
Member
Reply 4 by Biancoenero
Posts
8
I thank you, I will bring it to the tuner's attention.
The last time the tuner came he told me that some keys (I don't know which part) had not been "graffitata", what does he mean by graffitatura?
On the keys, I don't see where graphite can be applied!!!! Graphite is applied to the escapement pallets, but if the problem is something else, that won't help solve it. Graphite improves things, but it doesn't compensate for the malfunction of a part (for example, regarding the pivots or the springs!!!)
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Biancoenero
Member
Reply 6 by Biancoenero
Posts
8
I imagined... it's obvious he didn't want to waste time changing all the pins...
Well, to change the pins he would have had to remove the action and take it to a workshop; it's not an operation that is done in an hour.
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Biancoenero
Member
Reply 8 by Biancoenero
Posts
8
The action can also be disassembled "on site"; in fact, he did so and even changed the pins of two uprights, on the others he limited himself to "graphite-ing", once the action was reassembled... (because, fortunately, not all the keys get stuck)
Yes, okay if one or two need to be changed. If you have to change all the center pins, normally the technician takes away the entire action. I don't understand how they managed to graphite the center pins that are tightly fitted between two Casimir gaskets. 😳
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Biancoenero
Member
Reply 10 by Biancoenero
Posts
8
No, I think the graphite was applied to the head of the escapement lever (sorry, I don't know all the terms), to bypass the friction problem, taking a shortcut instead of changing all the necessary pins...
At this point, I think the problem is indeed the pins, if it even occurred to the tuner to replace at least two of them...
It is the humidity that creates these problems; in fact, if you bring the hammer closer to the heater from the side of the notch, you will see that the problem disappears. Unfortunately, if the humid air persists, the problem will reappear very soon.
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Biancoenero
Member
Reply 14 by Biancoenero
Posts
8
No, but some keys are as if they had double escapement (delayed, though 😵)...
