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If he installed the knuckles any closer than 16.5mm (with current issue SS) hammers he would have serious problems. And if he copied the original 15.5mm configuration, forget it...beyond impossible.

Peter Grey Piano Doctor

Would this be true for upright hammers too? I recently ordered a set of Abel hammers from Schaff, and had them bore and cove them. Should I be looking at shaving down these hammers before installing them? Thanks. Sorry for the thread hijack, but it seems related.

Abel makes good hammers that will be more or less ready to install. There is always refining work that is possible with high-end custom work. Because of the physics involved, however, excess hammer weight in uprights is not as detrimental to touch weight, like it is at the end of the hammer shank of a grand. In an upright, the weight is supported more by the system itself in a vertical plane.

If I were you, I would weigh each hammer. I use a scale that measures to the hundredth of a gram, but a tenth of a gram is probably fine. Graph things out in something like excel so you can see the inconsistencies in the line. This takes like 10 mins. So, it’s not a big deal. You are going to find that the line is not consistent, and it is not as linear as the hammers may appear by sight. You can either smooth out the major problems, or you can adjust each and every hammer to produce a smooth line. That part is up to you and the kinds of tools you are comfortable working with. Some people work with disc sanders, I tend to work with sharp hand planes and chisels. You need to have excellent control over what you are doing. You need to be able to take off 0.1 gram increments.

The relationship between the mass of the hammers and the touch of an upright piano is a lot different from that of a grand piano. In a grand piano, most of the mass is affected by gravity. In an upright, the gravity is mostly counteracted by the shank. In an upright, the jack spring has a big effect on the touchweight (I should say touch resistance), and there is no equivalent force on grand pianos. Also, the center of gravity of the hammer and butt assembly can be rising during part of the stroke, and lowering at another point. How the butt springs work is another variable. The mass of the hammer itself is a minor part of the system.

I am no physicist, but would think that all of the mass of the hammers (and that of the other components of the action train) is acted upon by gravity. Likewise, all of the mass of the upright hammers and other parts are acted upon by gravity. You say that in an upright gravity is mostly counteracted by the shank. Explain how gravity is counteracted by the shank. You cay the jack spring has a big effect on the touchweight. Please explain. Explain why there is no equivalent force in a grand. Are not the hammers and whippens rising in a grand during a stroke, and likewise falling? Are you saying that the mass of a hammer is a minor part of the system mass in an upright? If so, why?

I am not a teacher, and even if I were, I think I would like a much more capable student than you, but I can give you a simple exercise that should, if you were capable of learning, lead you towards understanding the difference between the forces on a grand hammer and those on an upright hammer.

Take a grand action out of a piano. Lift a hammer to any point in the normal motion that it follow if it were in the piano. Then let go of it. Then lift the hammer to a vertical position, approximately to a position along the stroke that it would be if it were an upright hammer. Then let go of it. The difference in how it moves is approximately the difference of how the forces apply between the two actions.

man, so much aggression in this thread. Did the OP get scared off?

When I had my 1980's S&S B action replaced, I talked to about 4 different rebuilders. Everyone of them told me I'd they would have to include the touch weight in the estimate no matter what manufacturer I chose for the parts. By the way, I did choose WNG. It's AMAZING, but a big part of that is that my rebuilder did and excellent job on the action geometry and tour weight.

BDB, I chuckled as I read the first sentence of your reply. Thank you for telling me how stupid I am as a lead in to your explanation. I will leave it at that.

Others can judge the depth and merit of your example.

Would this be true for upright hammers too? I recently ordered a set of Abel hammers from Schaff, and had them bore and cove them. Should I be looking at shaving down these hammers before installing them? Thanks. Sorry for the thread hijack, but it seems related.[/quote]

Emery, the dynamic touch response (inertial touch weight) is controlled by the hammer weight and its distance from the action center. This aspect is the same no matter the orientation of the system, vertical, horizontal, upside down, sideways. The mass of the hammer head, multiplied by the action ratio, is the largest component of the dynamic touch weight, perhaps more so in the vertical than the grand action.

I re-hammered my middle-aged Yamaha U-1 with Abel Natural hammers. I weighed the hammers of the shanks, dead weight, and added or removed weight to produce a smooth continuity. I didn't measure the strike weights of the completed hammer assemblies, because I felt the inertial hammer resistance was the most significant part of the equation. I am very pleased with the result, and other technician/players have commented on the exceptional touch response.

Ed_Sutton, you goofball, stop that! Someone might think you are actually serious. I can’t tell if you are trying to be funny, or what, but that was the craziest thing I have read in a long time! I mean, I laughed a little bit, but still.

Anyone can wave a broom around - with the weight at the top - near the vertical position and compare what it feels like to do the same kind of motions around the horizontal position. There are different aspects in play, and the feeling in your arms and body will eventually tell you all that you need to know. You can call it whatever you want and put fancy terms on what you think is happening, but at the end of the day, the body knows the difference. Uprights and grands do not function the same.

I guess it is a moot point as long as the person installing the hammers takes the time to produce a smooth hammer scale. But, adding any kind of weight is horrible idea. With all the impacts and vibrations, it will come loose no matter what. Weight should only be removed.

erm...ok...

At the very least one might observe that this is not the quality of dialogue to which we are accustomed in here. Especially not directed at someone of Mr Sutton's extensive experience, and espcecially not from someone who joined this Forum five days ago and whose Profile reveals nothing regarding his piano experience.

There is a distinct aroma of troll.

I was looking to see how to unsubscribe from Pianoworld, but can't see how. Can anyone advise?

Are you suggesting that using the weight of a broom to feel the difference between the vertical and horizontal differences of weight is trolling? I hope not. Because there is a huge difference. Wrap a towel around the end and see how it changes. The weight is of little consequence to the upright orientation. It makes a HUGE difference in the horizontal plane.

Greetings,
I can't agree with that. I have installed 1/2 gram or less in hammers to make an exact SW curve. This was needed after tapering both sides of each hammer on a jig that renders all physical dimensions such as width the same. For some reasons, identically sized hammers will have a slight variance in weight. I smooth the curve with a 3/32" blind hole drilled in the side of the hammer filled with a length of lead solder cut to weigh what I need in that hammer. Dropped in the hole, lightly swedged with a small punch, and a drop of CA on top, I never had one loosen.
In a lot of action work, even DW can be had when the slight differences of SW are smoothed by allowing FW to go above and below the curve, as needed. I see this taken to extremes in many older keyboards, where the FW doesn't actually form a curve, but, rather, a scattershot pattern that gradually slopes downward as it moves up through the keys. Two adjacent keys with a 7-10 gram difference between them is not even enough. I like to have the adjacent keys within 1 gram or so of each other, and sometimes that requires combining the alteration of FW and SW to keep either of these curves from becoming too aberrant.

To add: Departures from the ideal curve will not give a result that is worth the trouble if the capstan line is not true and straight. The slight differences in AR will give your weights too a wide range to be compensated for with subtle departures. Inconsistent parts will cause the same problems, another reason I have moved to the WNG parts,(as if felt bushing and pinning wasn't enough!). I have done a number of actions with smooth FW and SW curves and the WNG parts are the ones that produce a smooth DW curve as a result. The more consistency, the better.

Regards,

No. I am suggesting that the rebarbative tone you have employed towards Mr Sutton and to others in the 32 or so posts you have made since joining five days ago is more typical of a troll than of the friendly and helpful interaction that generally takes place here.

I will not engage further with you.

If you've been able to get the leads to stay with the CA, and you've checked it over a long period of time, then your approach must be working. I tried a similar approach and it developed problems for me over time. However, I didn't do a blind hole. I was more concerned with getting the extra weight added to be centered. Since each hole had a different amount of lead, I was concerned a blind hole wouldn't allow me to center the weight. Some people do the blind hole in the key sticks as well. Instead of messing around figuring out how to add weights over the long term, I simply reduced the heavy hammers to get a smooth curve with the lighter hammers. That makes more sense to me, as it is the most stable and there no chance of anything coming loose. But, again, if you have a foolproof method that works for you, then there is nothing wrong with it.

I'm sorry you won't be engaging anymore. That's sad. But, rebarbative is a great final word. I've never heard it before. I hope someday I have a chance to use it in a sentence myself.

well, if it is a question of three light hammers getting a small weight installed, or sanding 1/2 gram off of 60 others, I think I will stick with my approach.