Hammer touches the string twice

In my opinion, it could also depend on the hammer regulation being a bit too far apart.. let's ask Paolo Pianoexpert for some light

Hi

But maybe I posted in the wrong section? Is that why I'm not getting any answers?

The key dip is certainly insufficient. Generally, new pianos are found in these conditions. It is thought that minimizing the dip makes the keyboard seem "easier"... but a minimal variation in relative humidity can cause this distance to vary, which could become, as in this case, insufficient. The technician will know how to adjust themselves to "regulate." If you see them looking lost or declaring that it is "...a long and complicated job" or "...let's let it settle..." etc., just suggest placing small, thin pieces of cardboard under the screws of the keyboard center rail. This quick and safe system does not alter the proportion between the white and black keys and restores the correct dip, which for uprights is generally around 10 mm (never less than 9.5).

The correct dip must also take into account the hammer-to-string distance, which is generally about 45mm in uprights.

It could also be that the dip is correct and that this latter mentioned distance is greater. In that case, one must intervene on the hammer rail, placing sufficient thickness between the moving part and the fixed part of the rail (you can see the moving part move by operating the piano's left pedal).

Naturally, this adjustment must be compensated for by raising (unscrewing) the brass pilot under the heel of the capstan (which can also be made of felted or grafitized wood) until the escapement lever has no play with the hammer butt.... but so that it returns underneath easily. The correct regulation must not cause a sensation of emptiness at the beginning of the key depression. Such emptiness, besides being annoying, decreases the impact energy of the hammer against the string.

I hope I have been clear and helpful

Thank you for the very detailed explanation. You were very clear. Compliments on the site and the video tutorials, I am slowly watching them all.

pianoexpert wrote:

The key dip is certainly insufficient. Generally, new pianos are found in these conditions. It is thought that minimizing the dip makes the keyboard seem "easier"... but a minimal variation in relative humidity can cause this distance to vary, which could become, as in this case, insufficient. The technician will know how to adjust themselves to "regulate." If you see them looking lost or declaring that it is "...a long and complicated job" or "...let's let it settle..." etc., just suggest placing small, thin pieces of cardboard under the screws of the keyboard center rail. This quick and safe system does not alter the proportion between the white and black keys and restores the correct dip, which for uprights is generally around 10 mm (definitely not less than 9.5).

The correct dip must also take into account the hammer-to-string distance, which is generally about 45 mm in uprights.

It could also be that the dip is correct and that this latter mentioned distance is greater. In that case, one must intervene on the hammer rail, placing sufficient thickness between the moving part and the fixed part of the rail (you can see the moving part move by operating the left piano pedal).

Naturally, this adjustment must be compensated for by raising (unscrewing) the brass pilot under the heel of the capstan (which can also be made of felted or grafitized wood) until the escapement lever has no play with the hammer butt.... but so that it returns underneath easily. The correct regulation must not cause a sensation of emptiness at the beginning of the key depression. Such emptiness, besides being annoying, decreases the impact energy of the hammer against the string.

I hope I have been clear and helpful

Good morning,

in effect, the technician told me to let it settle, and to do the regulation at the same time as the next tuning; since for now the tuning is still holding, I haven't called him yet. Anyway, I have started to verify some of the measurements you recommended.

Firstly, the key dip seems correct; I measured it with calipers and it is exactly 10 mm. The string-to-hammer distance seems low to me, about 42 mm. And the escapement points on the various keys are all different: some keys are correct at around 2 mm, others at 0 mm, but most reach even 7 or 8 mm.

Now I am asking if I could regulate the escapement myself on at least a few keys to verify, or if the string-to-hammer distance must be corrected first and brought to 45 mm. But I seem to have read here on the forum that if the string-to-hammer distance is low, it should not affect the double strike of the hammer on the string at pp. So can I leave it at 42 mm and regulate the escapement?

One last thing: I haven't understood which is the escapement regulation screw on a Yamaha upright. Is it by chance that small eyelet found above the wooden strip, with the escapement button underneath?

If that is it, in my opinion, a specific tool is needed to turn it, or am I mistaken?

Regards to all and thank you

Suitable small tools are required. It all seems a bit strange to me... perhaps those keys that apparently bounce back have 0 escapement! 42 mm is too little. With 45 and 10 of dip, it should work. Does the problem happen to occur on a black key? I don't see anything that needs "settling." It just needs to be adjusted! Tune it properly and regulate it.

Good evening nicpag, if the measurements are exactly as you observed, then it is evident that the piano is totally out of regulation

When a piano ages and wears down, the hammers

become shorter, the delayed movement between the wippen and the hammer head increases, and the

parameter hammers (jack bushings/parts) become thinner, but the key dip does not increase accordingly. Therefore, the key

reaches the bottom of its stroke before the mechanism completes its own cycle, and the

parameter hammer cannot perform its task.

In a new upright piano, this is usually caused by inadequate key dip in

proportion to the hammer strike, as Maestro Paolo rightly said,

such as an escapement too close to the strings or parameter hammers out of regulation which cause the problem..

x which in your case is simply a matter of correct regulation of all the parts in question.

Regarding the regulation of the escapement, I confirm that an adequate tool is needed to turn the eyelet screw

as you have already noted, x so since it is a piano under warranty, I advise you not to try if you do not possess the correct tool

to avoid damage.

I do not agree with the technician's choice regarding waiting for the mechanism to settle and regulating at the next tuning;

otherwise, I cannot explain why, when you purchase a new piano, I ask you for 300 - 500 euros for the preparation, which consists of all the adequate regulations, tuning, and voicing.

Good morning,

while keeping in mind that I must have it regulated by a technician, I am continuing this discussion for informational purposes.

The keys that rebounce are almost all of them, both those with 0 mm let-off and those with 7-8 mm let-off. In particular, the F# in the 3rd octave rebounces quite a lot and has a 7÷8 mm let-off. I was wondering, but generally speaking, are the keys that rebounce those with low let-off (0÷1 mm) or high let-off (7÷8 mm)? But in my opinion, even when regulating the hammer-to-string distance to 45 mm, one must still regulate both the let-off and the hammer regulating screws. The let-offs are not all the same; they are all different. After playing loudly, what should the string-to-hammer distance be? In some keys, even that is low, less than 1 centimeter.

NB: Are these adjustments covered under warranty?

Warranty is a very random concept in the field of pianos; one could say it is due to the home climate, or that it has been tampered with by other technicians, etc.... a serious retailer will intervene if a problem is found, even without a warranty.

The hammer rebound on uprights is pathological; one must seek the correct ratio between backcheck, hammer-string distance, and key inclination.

The play on the pilots must be checked, the escapements must be registered, and the spring tension must be verified, as well as the regulation of the hammer rails and the action of the dampers.

In short, everything must be re-checked from scratch; it is useless to modify a single parameter in isolation. Nona would solve nothing.

Entrust the inspection to a good technician.

giovannig wrote:

Warranty is a very random concept in the field of pianos; one could say it's due to the home climate, or that it has been tampered with by other technicians, etc.... a serious retailer will intervene if a problem is found, regardless of the warranty.

The hammer rebound on uprights is pathological; one must seek the right ratio between the backcheck, the distance from the string to the hammer, and the key inclination.

The play on the pilots must be checked, the escapements must be registered, and the spring tension must be verified, as well as the regulation of the hammer rails and the action of the dampers.

In short, everything must be re-checked from scratch; it is useless to modify a single parameter in isolation. Nona would solve nothing.

Entrust the inspection to a good technician.

Thank you Giovannig for the response; indeed you are right and others have already advised me that I must have it regulated by a technician; at most, I could have regulated the escapements and perhaps the hammer rails. By the way, I know that you are also skilled and an expert on pianos, can you tell me how the hammer rails are regulated?

I believe the hammers are the least of your problems; I regulate them at the very end so that once the pusher has exited the nut, it does not move too far away (half a millimeter of clearance between the pusher and the nut skin with the key fully depressed, after playing half a fore). If everything is correct by doing this, one returns to the canonical measurements for the parata, achieving optimal repetition and furthermore, when playing multiple notes simultaneously with the same intensity, the hammers are all stopped at the same distance from the strings, meaning a certain uniformity of operation is observed.

Good morning everyone, I had the piano regulated and now everything works perfectly, it sounds great. Thank you all for the suggestions you gave me. :-)

I am arriving late, I am reconnecting to the discussion about bouncing hammers, in the discussion from 29/02/2016

I ask Maestro Paolo: regarding putting small spacers under the screws of the central bar of the keyboard; which is the bar in question?, that is, where should I position the small spacers?

Thank you

You must remove all the keys and you will see that the frame which holds behind the key rest felt and in front of the oval key guide pins, has a central bar where the round center pins of the keys are installed. You must unscrew the screws of this central bar and place small paper shims (start with one) under the bar at the position of the screws.

When screwing them back in, the central bar will be higher and therefore the dip of the white and black keys will increase... while preserving the original proportion.

You must also, as already mentioned, check the hammer-string distance so that it is not excessive (45-47 mm). When the proportion between the two measurements is correct... the keys will not "strike the string twice" even at a "pianissimo" touch.

....late....Thank you Maestro!