That was a great thread on the phenomenon known as the marshmallow zone a few weeks back! I think it was Jeff (Unright Tooner) who started it, and it spurred a lot of good comments.

Now that I've switched to impact tuning completely (CyberHammer on verticals, tap method on grands), I've noticed that there really is no marshmallow zone. Sometimes there's a slight amount of twisting that needs to be undone, but it's far less than what I used to perceive using a smooth pull method. I think sometimes we tend to make things harder than they need to be. With unisons, I think the least amount of manipulation that gets the pin and string where it needs to be is best.

Loren:

I do not think any hammer technique can make the MZ disappear. It is still there, but the technique is using it’s characteristics to an advantage.

For instance, a particular piano that I tune regularly had more spring in the pin than rendering friction. It was difficult to tune stably. So I decided to increase the rendering friction by screwing in the pressure bar. For some reason I thought it would be better to leave the top octave and a half where it was. The result was that a smooth pull worked very, very well. Little overshoot or banging was necessary, except for the top octave and a half. I will be screwing down that part of the pressure bar next time. In fact I am trying to convince myself to do this with more pianos.

The point that I am making is that the size and shape of the MZ was changed so that a particular hammer technique matched it and made it a non-issue. That is what Ken Burton’s great book Different Strokes is all about.

I have no reason to doubt that you are accurately reporting your experience with impact hammer technique. I see little self aggrandizement in your posts. I have not tried an impact hammer, but others have and reported different results.

Here’s how I am looking at stability lately. The difference between the ideal position of the pin and the actual position of the pin (in cents change of pitch) must be less than the amount that the bearing friction can hold between its speaking and non-speaking parts (in cents change of pitch) when played loudly or when there is a reasonable change in the environment in order for a string to be stable. Now if the smallest amount that a particular hammer technique can move a pin is larger than this amount, then you will not be able to always have a stable string on the first try. But even if a particular hammer technique can move the pin in small enough increments, the tuner must also be able to discern when the pin is close enough to the ideal position and then render the string if necessary. If he cannot discern this, then another hammer technique would be better, even if it may take multiple tries.

And let’s not forget what the expectation for stability, or for just tuning accuracy, is. Perhaps (and I really don’t know, I am not exposed to other’s tunings very much) a certain hammer technique always works for a particular tuner because it meets their expectation for stability, not that it is always the most stable technique in a given circumstance.

Myself, I am very picky about my temperament; probably to a fault. I find that I must make every note in the temperament very stable in order to have the RBI progression and the color of the SBIs to my liking. I have to use various hammer techniques to do this. Another tuner may feel that progressive CM3s is all that is required (and they may very well be right) and have a hammer technique that works regardless of the piano.

Anyway, I am very glad you are bringing up this subject again. Maybe there will be some tips come out of it about tuning the seventh octave.

What about the sixth octave? I think that section is even worse!

OK, then what tips do you have for the sixth octave? I'll just transpose up an octave!

I think the biggest culprit in stability (or lack of it) is flagpoling, and that any technique that minimizes it will lead to more stable tunings. For me, anyway, impacting or tapping/bumping provides the advantage of recoil, pretty much straightening the pin quickly and stably. Some very gentle nudges back and forth without a change in pitch tell me the pin and string are set.

My marshmellow zone was reduced dramatically when I got a Fujan.

See, that's my point. If different levers and techniques change the perceived marshmallow zone, then that tells me that it's more a perception than anything.

When I put a coat on to go outside, I do not percieve the cold as much. It does not make the outside temperature warmer because I don't percieve it as much.

No, but it does diminish the relevance of the cold and its effects.

*edit* Good snow tires on your car don't reduce the amount of snow and ice on the road, but in the same way, they reduce the effects of both and their relevance on your ability to control the car.

Car tires may be a good analogy. All season radials are good all-around tires. But there can be better choices for specific uses, like off-road or racing. Likewise there can be better hammer techniques than impact for specific uses, like difficult pinblocks or ultimate stability.

This is like deja vu all over again, especially with Keith involved.

OK, let’s examine flagpoling. Flagpoling exists because the plane that the torque is applied is not in the same plane as the resistance to the torque.

Now please explain how impacting “minimizes” flagpoling itself, not just its effects.

If I find myself frustrated with any “Voodoo Engineering” on this subject as I was a while ago and which precipitated me leaving this Forum for a time, I will try to consider it to be an “Indulgent Mystery” and just exit the Topic.

On a vertical, you don't have the leverage necessary to flagpole the pin. You're holding the lever virtually at the pin.

Loren:

The force is still assymetrical. It does not matter where you hold the lever. The lever only has one handle.

See 'ya Monday....

Jeff, depending on where you grab the handle, you can gain more or less leverage. You know that. If this were not true, extension levers would be useless.

Try it. Using your traditional lever, place it on a pin. Grasp the top if the lever and try flagpoling the pin. Now grasp where the head meets the pin and try the same thing. Are you saying there will be no difference?

I've suspected for some time that my tuner was also a Jedi.

Loren:

Two things come to mind when you “choke” up on the handle of a traditional tuning hammer that would have little significance when considering an impact hammer.

First, the amount of bend in the handle will be less. Those that prefer a stiff lever see it as a way to avoid this problem. I don’t think it makes much difference because the pin twists without actually moving much more than the lever bends. Second, since the handle of the hammer is at a greater than 90 degree angle to the pin, when you “choke up” the plane of the force and the plane of the resistance are a bit closer together and, yes, would reduce the flagpoling effect a bit. That is a reason that I am considering tuning the high treble of grands with the left hand so that an extension is not needed in order to reduce the flagpoling.

But neither of these effects should pertain to an impact hammer. The force still is applied by the center of the mass of the hammer, regardless of where you hold it, unless you are “muscling” it and not using it as an impact hammer. But in all fairness I suppose it would be impossible to not “muscle” an impact hammer a little bit.

Here is a link to a PTG Pianotech post about hammer technique that I have browsed through but have not studied yet. I think you will appreciate it:

http://ptg.org/pipermail/pianotech/2011-January/033943.html

Jeff, I'm just asking that you try it. Put the lever on the pin of an upright, with the handle at 12:00. Grasp at the top of the handle and try pulling down (as in bending the pin downward toward the floor). Now grasp it at the head and try the same thing. Is there a different in leverage and your ability to bend the pin?

Loren:

Of course there is a difference in leverage. And for the same amount of force, there will be less flagpoling. But when the force is increased to the point that the pin moves, the amount of flagpoling will be nearly the same [Edit: When actually tuning, not just flagpoling a pin as in your example]. Any difference, as I pointed out, is not due to the length of the lever, but the difference between the planes of force and resistance.

But aren’t you changing the subject? I thought this was about impact hammers.

But to deliberately change the subject, can I ask you to try something? This is not to prove a point, but answer a legitimate question. I have wondered just how small the average change in pitch is for each pin movement that an impact hammer makes. I am not sure the best way to do this. Maybe if you give a string a movement up, measure the pitch, then move it up with, say, ten more small impacts. (Now I mean impacts that you know have moved the pin. I image that a pin could be tapped without actually moving and I would hope that the difference can be felt.) Then measure the change in pitch and divide by ten. I realize that this could be different for different pinblocks and in different parts of the scale and the phase of the moon (did you see it this morning!) but just to get an idea.

Milli-cents. (is that a new word?) I can impact with the CyberHammer in the sub-cent range.

I didn't change the subject. You asked me to explain how using an impact lever lessens the chances of flagpoling over a traditional lever, so I did (using a traditional lever method as my example). And I still maintain that because of where the lever is grasped, there is less chance of flagpoling because the leverage required to do it is, by your admission, decreased! The point being, the pin is rotated with less possibility of bend.

Lol, looks like we're dug in pretty hard here....I have a feeling we're going to have to agree to disagree.

But isn't the idea of using an impact lever that the momentum of the weight in the handle moves the pin? If so, then what difference does it make where the handle is grasped? If not, then what is the idea of using an impact hammer?

There is no bending before breaking the static friction of the pin. As there would be if you were tuning lefty with lever at 11:00 or righty with lever at 1:00.

OK, why do you think there is no bending, because of a bend-o-meter or the results? Obviously it is the results (as you perceive them...) Again, that does not mean that the pin does not bend, as in flagpoling. Putting on a coat does not make it warmer outside.

It is too bad that we cannot get beyond this and discuss what an impact hammer actually does.

Jeff, Using a traditional llever, you can FEEL the pin bend and HEAR the pitch of the string change before the pin turns. You don't hear/ feel that?

If the pin suddenly rotates all at once, you neither hear nor feel it. Because you are not pulling in a lateral plane.

OK, you neither feel the pin bend not hear the pitch change before the pin turns with an impact hammer. That does not mean it rotates all at once (how could it, it is still flexible). I have no idea why you think a lateral pull (whatever you think this means) does not exist just because an impact wrench is used.

Maybe this link can help us get on the same page: http://en.wikipedia.org/wiki/Impact_force

I think the confusion is about 2 kinds of flagpoling.
An upright impact hammer eliminates one of them, the grand impact hammer I've seen removes both types.

Imagine a normal hammer on the pin at 12 o' clock. If you
push the hammer away from you the pin will not turn, but just bend upwards (flagpoling 1). If you push the hammer (hold it near the top) in the plane of the pinblock, say to the right, the pin will turn clockwise due to the torque but also bend to the right because of the force (flagpoling 2).

If you try to turn the pin you can eliminate flagpoling 1 by being very careful to apply force only in the plane of the pinblock, but not flagpoling 2.

With an upright impact hammer you throw the handle left-right, and the moment it hits it will apply an impulsive torque AND an impulsive force (left to right). The latter still causes flagpoling 2, but flagpoling 1 is eliminated by construction.

The grand impact hammer looks like a 'T' and when you "throw" it, it has only angular momentum, but no linear momentum and the impulse is pure torque.

Harpsichord tuning hammers look like a 'T'; when you turn the pin you apply opposite forces to both sides of the upper line of the 'T', resulting in no force, just torque and hence no flagpoling (if operated correctly).

I think Jeff was talking about flagpoling 2 and Loren about flagpoling 1, hence the confusion.

Kees

Thanks Kees, I think you nailed it!

Well, Loren did use flagpoling 1 as and example, but I don’t see where this type of flagpoling would occur with proper hammer technique, unless it was done intentionally. I sometimes do if the rendering is extremely poor. And when the hammer is in line with the string, flagpoling is not an issue, anyway.

Jeff, why don't you design an electrical impact hammer? Something small with a flywheel. You just put it on the pin and press the button. Optionally plug it in the USB of your laptop to let your ETD control it; hit the key ...... tap tap taptap tap - done. Anyone can do it! Sell it at Wallmart for $39.99. Mass produce it and miniaturize it and put one on every pin on the next generation of auto-tuning Chinese piano's.

If it works you should be able to retire on it. Probably won't make you very popular here though.

Kees

I do not think it would work well enough to suit me. But why don't you try it?

So the question remains....if one can set a tuning pin easily and confidently and without guesswork (regardless of technique or kind of lever), does the MZ still exist? I still say it's a perception thing, and that it's for that reason that for some it's big, for others, it's small, and for still others, it's non-existent.