Hammer position issue after hitting the string

AlvinC · 2024-07-02T02:30:29+00:00

Hello guys, here is an issue that bothers me for long: I found out some hammers of my grand piano are not in the right position after hitting the string even...

Josephine

JohnCW

Do you think it's a good idea to turn the drop screw a little bit to see if this fixes the problem of AlvinC's piano? (I'm asking because I want to learn from this, if the first video is made after playing the note the hammer looks too close to the strings).

JohnCW

Josephine Do you think it's a good idea to turn the drop screw a little bit to see if this fixes the problem of AlvinC's piano?

No. That's just adjusting things willy-nilly. To do the job right, everything needs to be adjusted correctly. But the staring point is having a somewhat correct repetition spring tension. And as an overly strong repetition spring is one of the main reasons for the hammer not checking on a soft blow, the best place is to start there.

I'm assuming the back-check itself is set close to correct as in the video the two hammers checked in a near identical place on a firmer blow.

Josephine

JohnCW

Thanks for explaining!

AlvinC

JohnCW Hey John, no problem as I am not in urgent need to restore it correctly. I guess the hammer tail is fine as I switched the OK hammer to this problematic key for test and sadly the problem does not disappear.
Happy and safe trip!

AlvinC

Josephine Hi Josephine, correct me if I am wrong since I am not a technician and only a piano fan. But I am indeed interested in learning regulation as I can understand much better of the piano I play.

Josephine

AlvinC

I'm not a technician either, I just like to learn about pianos 🙂

Pallas

Josephine I'm enjoying all of your questions. I don't even know what to ask, so I've not been participating, but I'm very interested in what you're learning.

AlvinC

JohnCW
Hi John, when you are available could you help to check the spring of below? the first hammer is the problematic one and it needs really heavy velocity to set on check
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JohnCW

Repetition spring is to strong. It needs to be weakened to remove that bounce at the top of the hammers travel (which I assume you should be able to feel through the key).

I believe you said you had previously adjusted it so I assume you know how to do this and have the tool to hook the butterfly spring in and out.

AlvinC

JohnCW Hi John, thank you for the prompt response. what about the spring of the other two keys shown in the video? it's not easy for me to tell which one is too strong by watching its speed

Rubens

To pinpoint the location of the problem, would it be a good idea to just swap hammers or wippens with the neighbor key and see if the problem has shifted to the new key?

AlvinC

Rubens Hi Rubens, I did swap the hammers earlier and the problem still exists in the problematic key.

Rubens

AlvinC Ah, so it's almost certainly something in the wippen.

AlvinC

Rubens Yes, now I just need to test whether adjust on the repetition spring can help. Thanks.

JohnCW

AlvinC Just assess the rise speed of each hammers when released from check. As I mentioned in a previous post they should rise about the speed someone gets up from a chair, with no kick/bounce at the top of their travel, and no kick should be felt through the keys.

AlvinC

JohnCW Thanks, John. I will try to adjust and keep all of you posted later.

JohnCW

AlvinC If you're going to try adjusting the repetition spring do yourself a favour and buy the Hart Spring Tool. It is considered the best going for hooking out those pesky butterfly springs.

Now you might think it's overkill just to adjust one spring. But look at it this way, there are bound to be more among the other 87 that need adjusting.

AlvinC

JohnCW Dear John, thank you so much for making the regulation look like more desperately. Just kidding. I do respect every technician, the regulation is really time-comsuming and tedious. I am new to this forum and regulation and so grateful to have all your generous and friendly replies.
BTW, I did try to lower the tension of the spring with tool in the weekend. It improved but still the problematic key takes harder blow to be checked by the backcheck (see below video). So I just want to know what is the standard velocity for the hammer to be checked? I always worry to set the spring strength too low or damage the spring.
[

JohnCW

AlvinC Repetition spring is still to strong. If you excessively weaken it by bending it simply won't push the hammer up out of check when you release pressure on the key.
It needs to rise without that clear bounce/kick at the end of its upward travel when released from check.

AlvinC

JohnCW OK. What about the hammer right next to it？I guess it is with the correct tension.

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