David,
The creation of a positive bend at the terminations is, I think, a good thing tonally. When replacing broken strings, I have often listened to an individual newly installed string, before and after making positive bends at the termination, and the additional clarity of tone, as well as better definition of pitch, is very noticeable. I presume that the bend gives the termination a bit more of a definite placement. The reality is that piano wire doesn't terminate at a point (it actually seems to terminate somewhere beyond the bridge pin, agraffe, or capo in practice, but that termination is variable, as we find when reading pitch to the tenth of a cent in real time). But the bend makes it behave more as if it terminates at one spot, compared to the ill-defined curve approaching and leaving the termination point, if you don't make the bend.
Hence the fad of simply going to a grand piano and pushing up on the strings from beneath (action removed), as promoted by many in the 80s and 90s (if memory serves - I'm thinking Susan Graham was one of those who advocated for that): it did give more clarity and definition of tone. That's where the reasoning for the Strate-Mate came from. OTOH, doing this may often make it impossible to get the strings level, should one go back and wish to do that. I know because I have been there and done that. I was the one who pushed up on the strings (either by hand with a tool, or with a Strate-Mate). I was the one who later found it impossible to level the strings.
My own practice now - for many, many years - when I restring a piano is to start with the left string and give it a moderate positive bend, pulling up enough to make a bend, but far below the force that would make a "maximum" bend. I then pull the right string to make the string level read level, and pull the middle string to meet the bottom of the level. I almost never find a unison where this is not possible. I do that with the level at the hammer contact point, nowhere else.
When leveling strings on a piano I am coming to for the first time (from the factory, from somebody else's work), I do often find some unisons that can't be made level to the level (bubble centered). Not a big deal, mating can still happen, but that means some hammers that will have to be customized/slanted.
When I first started leveling strings, I did it at the front termination, or behind the dampers where that was more convenient. Having done that and then tried to mate hammers, together with checking of one sort or another over the years, has taught me that pianos are quite inconsistent when we bore down to the refinement we are seeking in mating hammers. We are talking of differences less than 0.5 mm. Unison to unison with agraffes, there is often that much difference from one to the next, as you will find when playing George Crumb, and laying the glass rod across a section of strings, or doing similar effects. Many unisons will not be affected by the thing laid on them at all, will simply ring free. Which stands to reason, as it depends how the threads happen to be oriented, both in the plate and on the agraffe stem, and then on how much the agraffe is tightened down to orient it correctly. There is bound to be a variance of string height from unison to unison.
Bottom line, it is better to have an efficient process to get quite good, repeatable results in a reasonable period of time, rather than to over examine. There are lots of ways to get strings of a unison in a plane with one another, approximately level and parallel to the keybed (well, assuming the keybed is a flat surface - let's say parallel to the hammer flange rail). Developing the chops to accomplish this efficiently is far more important than counting the angels on the heads of the various pins involved in the close theoretical examination of the question from all available angles. (Not to mention the weighty issue of whether to customize the hammer blow to each of those different string heights, and on and on). Actually, pianos can sound quite good when you decide where "good enough" is and stop there. <G>
As for the tonal effects of kinks in the speaking length, I agree with Ron: I never heard any, even where I have seen fairly enormous kinks (made to avoid damper lift wires, sometimes), not to mention knots in the speaking length. Doesn't make sense, but if you can't hear a difference . . .
Concerning the level of strings changing over time, as pitch drops and rises and the strings are tuned, I have not found this to be significant. Going back over pianos whose strings I leveled several years ago, I do not find that issues have arisen. When I find an occasional unison out of level, I find that I can't level it now - meaning almost certainly that I tried and failed the last time and called a slanted unison good enough. I do not find "chatter" (random up and down strings).
I will say that when restringing, I pull about 25¢ sharp, make the back bends (aliquot and bridge pins); then pull 25¢ sharp again before making the front bends. Typically this leaves the piano slightly sharp, and it will go flat shortly. So the termination bend is pretty close to where it will be when the piano is at pitch a year from now and more. This procedure seems to provide a pretty reliable end result. At least I haven't yet found a reason to change it.
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Fred Sturm
University of New Mexico
fssturm@unm.eduhttp://fredsturm.nethttp://www.artoftuning.com"We either make ourselves happy or miserable. The amount of work is the same." - Carlos Casteneda
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Original Message:
Sent: 04-20-2017 05:44
From: David Skolnik
Subject: String leveling stuff
Remarkably difficult discussion to wrangle. We've been tracking the idea of 'level' (including orientation, relation to hammer, degree of precision), tools and techniques of measuring, tools and techniques of altering. I read through comments again and would try to add two things, even if it might just be some manner of re-stating:
- While consistent string plane and 'horizontality' (sorry Jim, and thanks) of unisons to keybed seem to be the idealized concept, the reality can be more often anomalous. Whether Fred is right, about inconsistencies originating more at the bridge notching than at the agraffe, or my own (and Karl's) experience of, at times, significant agraffe issues (or, possibly, previous leveling efforts that were overdone), there are times where the level can't be brought into compliance with that ideal, and we're left with trying to manipulate the hammer.
In an earlier attempt to draft these thoughts, I also included a reference to the idea of controlling the orientation of the natural curve of the wire, during stringing, which had been floated by Bradley Snook, and which Jim had at least experimented with. I mention this because we seem to have conflated the procedure of straightening out the stiffness-induced bend of the wire, coming off of agraffe or V bar, with the later-stage voicing process of string leveling at the strike point. It would be worth revisiting discussion of what we accomplish, tonally, by that straightening, but it seems likely that, if significant 'voicing'-leveling is done at the front termination, the result could be quite temporary, in the face of subsequent pitch raising (not so much with lowering).
For this reason, it might make sense, for the 'voicing leveling', to use a tool like Charles Faulk's String Leveling Tool http://www.faulkpiano.com/string_leveling_tool/ which can put that displacement farther away from the termination, thus making it more stabile. While I don't know if there is consensus about the tonal effects (or lack thereof) of kinks in the sounding length, I know RonN was quite comfortable in the belief that there were none.
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David Skolnik
Hastings-on-Hudson NY
914-231-7565
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Original Message:
Sent: 04-18-2017 23:05
From: Fred Sturm
Subject: String leveling stuff
I never found the Mother Goose mating tools helpful. In the first place, the sandpaper is too coarse. But more to the point, if your strings are in a plane, you don't need to do a bunch of single groove filing. I do most of my mating filing using a sandpaper strip the width of the whole hammer (the same ones I use for filing the hammers). It's just a matter of bearing one way or the other, to slant the crown of the hammer a bit.
If you are doing single string sculpting, that level will disappear with the shift pedal, making your una corda voicing sound unmated.
Although some people get pretty crazy about absolute level (shimming under casters and whatnot), the real point, at least for me, is to make things more efficient. If you do fine travel, fine squaring of hammers, sand your crowns straight, and level the strings, mating is already going to be quite good. In fact, often enough I omit it, because it isn't enough bang for the buck.
The other side to leveling strings with a level (as opposed to using the hammers as a template) is you have something more objective to use as a basis - a straight line on metal to metal is more reliable than felt to metal. I do check hammer crowns against a straightedge, but felt is fuzzy, and a straight line is a bit subject to interpretation. The tiniest discrepancy shows up when plucking a string against a metal leveling device.
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Fred Sturm
University of New Mexico
fssturm@unm.edu
http://fredsturm.net
http://www.artoftuning.com
"We either make ourselves happy or miserable. The amount of work is the same." - Carlos Casteneda
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Original Message:
Sent: 04-18-2017 21:32
From: Jim Ialeggio
Subject: String leveling stuff
That's my take Geoff...the leveling of the string plane is only one of the preliminary steps that mate the hammers to the strings.
Re the Mother Goose tool, it seems to assume the sides of the hammers aren't tapered and/or does not allow you to adjust the angle of the hammers strike point. Am I wrong about that? I use the shop-made version of Jurgen's clear plexi tools because of their ability to accommodate whatever the final conditions may be...but always looking for a better way to do things.
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Jim Ialeggio
grandpianosolutions.com
Shirley, MA
978 425-9026
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Original Message:
Sent: 04-18-2017 21:19
From: Geoff Sykes
Subject: String leveling stuff
After last nights PTG meeting I may have to rethink this a bit. The presentation was on voicing, and string leveling came into the conversation for a brief moment, 'cause, you know, strings are important here. Leveling strings on a plane, as Alan mentioned, was the point. Level the strings with, say, a bubble gauge and make sure all the unison's are level to that bubble level plane. THEN, assuming again that all the hammers are already "perfect", go back and use something like the Mother Goose tool to fine tune the hammers to the now known to be absolutely lever strings. Sort of makes sense. I'm enjoying this conversation.
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Geoff Sykes, RPT
Los Angeles CA
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Original Message:
Sent: 04-16-2017 16:07
From: Geoff Sykes
Subject: String leveling stuff
I've never understood the need to have the strings level with the Earth, which would be the result of using a bubble gauge. And I question the result of both this device and the Faulk device because both rely on the strings on either side of the strings being already leveled and of equal height to each other. If the strings of the neighbor note, on either side, are higher/lower than the strings currently being leveled then the result will be a unison whose strings may be in perfect "level" but only with the device, which could have been sitting there at an angle.
My take on this is that you have to first start with a hammer that is absolutely square with itself. The top striking surface of the hammer is at right angles to each side. Then the hammer and shank need to be traveled and burned so that the hammer is moving perfectly up and down without any twisting or movement. Only then can you level the strings and you should be leveling them to the individual hammer that is striking them, and nothing else. At that point it doesn't matter if the piano and/or the strings are level with the earth, or whether the gauge of your choice is telling you that the strings are level. If the hammer isn't striking all the strings in a unison at exactly the same time then either the hammer is not square with the strings, or the strings are not level with the surface of the hammer.
Assuming the hammer and it's alignment are already "perfect", the most reliable method I have learned is to use a thin length of felt, perhaps one of two millimeters thick and a couple centimeters wide, and roll it out across the tops of the jacks in a section so that they no longer escape when played. That results in the hammers going up high enough to block when played. Yes, the hammers should still clear the pinblock so that the action can be slid back in without problem. I then gently push down on the key until the hammer just barely blocks. I then pluck the individual strings, leveling up or down as required until none of the strings ring and any slight buzz, if any, is exactly the same for all strings when lightly blocked by the hammer and plucked. The result is that the strings and the hammer are now level with each other, which is really all that counts.
I fully expect to be corrected on this and look forward to learning something if my approach is wrong.
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Geoff Sykes, RPT
Los Angeles CA
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Original Message:
Sent: 04-16-2017 13:25
From: Jim Ialeggio
Subject: String leveling stuff
Re the missing bubble thread, I have tried every string leveling technique under the sun, and have and viewed the process with extreme skepticism. Not skepticism as to the utility of having the strings sit in a flat plane @ strike, but skepticism about the measuring accuracy of that plane. The repeatability of measurement with the tools I have used seems extremely subjective and liable to be misread, or at best unbelievably clumsy to use. The down side of misreading is that a misread string level is an absolute waste of time.
As often happens in the shop, it is when I try to teach someone else one of these ridiculous processes, processes that I have put up with for far too long, that the ridiculousness becomes obviously and completely untenable.
So my son Dave works with me in the shop, and is quite good at these picky-ass skills. However when I put him on this task and watched him struggle ineffectively with the measurement and then the adjustment, watching his frustration, I just said, "No more"!
It took a couple of hours and several tries to get this tool working…I had tried the concept a couple of years ago, but it didn't work, because close machining accuracy was required…ie there was too much slop in the plunger. I got the accuracy nailed this time
So once I got this working, I tried it out, and literally flew though the process with repeatability that escaped me before. I put him on the task, as a newby, and he moved pretty well too…none of this paying your dues crapola…the process sucked. It is in fact relatively easy if you have an appropriate tool.
Here is the interesting part for me. I had previously fingered the wrong part of the process as "the problem".
Many techs have complained, including myself, that adjusting the travel of the wire off the termination seemed to be the problem in this task…ie you read the out-of-level condition, adjust the bend, re-read level, adjust bend, ad nausem. The problem seemed to be that it was too hard to calibrate the exact force needed to adjust that bend to the precision needed. The result being that one was always going too far with the bend, then having to yank all the others further than they wanted to go.
But I was incorrect about the calibration of the bend being the problem. With a tool that stays seated on the string, and gives a consistent, repeatable reading of the string plane quickly, first, you don't have to figure out which string is high or low by tilting the reading tool or reading a bubble, etc. You just place the tool on the unison, allow the light plunger to drop of its own minimal weight, and lightly pluck the strings…actually not the strings, but the string in the singular. You don't even do the 3 string comparison, rather, if you hear the string vibrating, adjust it up. One at a time, since the tool remains on the string giving repeatable readings, gently incrementally increase tool pressure to the bend until that single string's vibration is stopped by the plunger.
When adjustments happen quickly in succession, ie very soon after the last try, the body retains a memory of the previous force used…the relative increase from try to try becomes much easier to incrementally calibrate. The difficulty of calibrating bend force is really a matter of being able to quickly read the change in string height, so you can incrementally increase adjustment force in a period of time that allows the body to remember the how much force was used last try.
So my take is it is not calibrating the force that is the difficulty in this task, but the difficulty is being able to read the out of plane condition very quickly with repeatable results.
Any thoughts?
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Jim Ialeggio
grandpianosolutions.com
Shirley, MA
978 425-9026
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