Pianotech

Expand all | Collapse all

String leveling

  • 1.  String leveling

    Posted 12-06-2017 20:12
    I have been trying my hand at string leveling with Joe Goss' string hook and level with no success. I've watched Ron Koval's and Richard Davenport's videos on this and as far as I can tell, my technique is the same, with one definite exception which is that I don't know how much force is needed to form the string in the intended direction. That said, the  amount of deflection observable in the videos seems to be less than what I ultimately worked up to without results. The strings I worked on do not seem to move.

    Can anyone offer guidance?

    ------------------------------
    Ruben Jackson
    ------------------------------


  • 2.  RE: String leveling

    Posted 12-06-2017 22:00
    Ruben,
    Just lift them a little higher. BUT be careful how far you lift them. I’ve seen several string leveling jobs that caused more damage than good. The strings had been “yanked” too high.
    Someone smarter than me needs to respond to that problem. Maybe restringing. Not sure.

    Sent from my iPhone




  • 3.  RE: String leveling

    Posted 12-07-2017 00:30
    Thanks for the feedback Thomas. I'll try a little massaging them up with a little more force.

    ------------------------------
    Ruben Jackson
    ------------------------------



  • 4.  RE: String leveling

    Posted 12-07-2017 08:51
    This question highlights what I feel is a highly suspect mechanical fiction that we have been told exists or have convinced ourselves we are  actually accomplishing in these leveling movements. ie, that the strings can be leveled to a high degree of perfection. And...this is the real kicker for me...that they stay leveled longer than it takes for the check to clear.

    Once the strings have already been lifted, the string is not going higher without a kink. Some contend that a kink is okay...I don't, as I contend that the new "level" is a temporary condition anyway.  

    When tone regulating, I have been skeptical of the claims attributed to this process since I entered this field, finding the claims counter to the mechanical capabilities of the materials. The claim does not take into account the fact that the angle the string forms when exiting the capo or agraffe will change each time the string is moved in tuning. When pressed for time in the field, this aspect, for me,  always will get shorted. The gains from anal leveling are not, to me, discern-able, or at best over-powered by other big ticket gains from other processes. For me, the time spent is simply not justified by the result, except maybe in a performance instrument that gets level tweaked aurally on a near daily basis.

    I think the problem is one of degree. There is wildly out of plane...and there is "out by thousandths". The Goss tool and all the others I am aware of do not differentiate well in terms of degree. They are often used as a "go-no-go" reading, and this "go-no-go" assumes a precision that is wildly over optimistic. It takes much practice to learn to use these "reading" tools consistently, and I contend that they are actually highly unreliable in their inconsistency. The Goss block and every other technique out there is fraught with false readings, or readings that confirm to manipulated tester induced wishful thinking. They do not hold their own if measured against an appropriate test device.

    I developed, what I thought was a repeatable reading device, and refined the device. It allowed a very precise and repeatable measurement of an individual string. However, since it took its "level" from adjacent strings...this is the real kicker for me(!)...the reading on a particular string would be consistent until I moved any of the strings in the adjacent unisons in ordinary fine tuning. This means the reference strings moved in simple tuning.  My fine tool proved itself unnecessary given the mobility if the system, even though they are cute and efficient to use, .

    Since the tools are "go-no-go", one must discern if there are gradations to the way they present their results. I think the level I am referring to is quite fine, measured in thousandths. 

    I think one must work to a much more forgiving tolerance in determining level at the actual string. Get reasonably close with your Goss tool, meaning not every string having the same damping,  and then mate the hammer to the string. But I remain highly skeptical of any claim that purports to be creating a perfect plane that lasts longer than a fresh tuning. 


    ------------------------------
    Jim Ialeggio
    grandpianosolutions.com
    Shirley, MA
    978 425-9026
    ------------------------------



  • 5.  RE: String leveling

    Registered Piano Technician
    Posted 12-07-2017 13:48
    Jim, 

    I, too, have thought long and hard about the efficacy of string leveling. Have come to the conclusion (for the time being anyway!) that it is worth doing… up to a point.

    We have found that a sequence of tune/level/tune/level/tune is our best investment of time. The second leveling pass always presents less to be done than the first, and this despite the intervening tuning, and the fact that those performing the operation are themselves more finely calibrated by that point. We have found that those pianos that have been leveled (with emphasis on making the tri-chords as planar as possible) are invariably closer to being both planar and level when revisited a year or more later. Also, making unisons planar and as level as possible, coupled with accurate hammer resurfacing, takes care of the majority of the hammer/string mating issues.

    As a practical footnote, we start with the Davenport tool (which is no longer available from the source), and finish up with the Goss tool (more refined readings, due to the absence of a magnet, but fussier to work with, for the same reason). Also, we do level the piano at the key bed (which is often the same as at the stretcher, but not necessarily so) before starting the string leveling work. We often do this with three people on one piano: two leveling and one tuning, concurrently. 

    YMMV,

    Alan

    ------------------------------
    Alan Eder, RPT
    Herb Alpert School of Music
    California Institute of the Arts
    Valencia, CA
    661.904.6483
    ------------------------------



  • 6.  RE: String leveling

    Registered Piano Technician
    Posted 12-07-2017 15:02
    Alan-
    You really must elaborate on that last sentence,  perhaps even with a video.  Why is three the magic number?

    ------------------------------
    David Skolnik
    Hastings-on-Hudson NY
    914-231-7565
    ------------------------------



  • 7.  RE: String leveling

    Registered Piano Technician
    Posted 12-07-2017 17:01
    David,

    I have enjoyed the help of several student work-study assistants and apprentices for many years now. There are usually at least two of them working at a time. Most regulation steps can readily be done by two people working side-by-side (one starting at one end of the scale, and the other in the middle, moving in parallel). So we do lots of stuff "two technicians at a time," their work being as consistent as if a single individual had done it all, thanks to the tools and techniques we use.

    With this image in mind, it shouldn't be too hard to imagine two people leveling strings at the same time. Add to that another person tuning, both ahead of the first and second levelings and after the second is done. Obviously, the smaller the people, the more elbow room they are going to have. (When working in such close quarters, a standing agreement concerning personal hygiene is in order.) This approach is productive, and especially useful when we have only limited access to the room a given piano is in.

    I have taken photos of this (and will have go dig them up), but not video. Will do so next time we drag out our string hooks and levels.

    And speaking of working in tandem, it is also a great experience for novices to tune a piano that someone else is tuning at the same time. (With ETDs, of course.) Makes tuning all alone suddenly seem that much less daunting!

    Alan

    ------------------------------
    Alan Eder, RPT
    Herb Alpert School of Music
    California Institute of the Arts
    Valencia, CA
    661.904.6483
    ------------------------------



  • 8.  RE: String leveling

    Registered Piano Technician
    Posted 12-07-2017 15:48
    Some people level with the thought that this is an activity that will "magical" results. I level strings for efficiency. I'll note that Jim Ialeggio says
    Once the strings have already been lifted, the string is not going higher without a kink.
    Alan Eder,  12-07-2017 13:47
    That is often true, and the question we face with a piano we didn't string ourselves is what, if anything, was done by those who came before us. For pianos I string, leveling is part of "lifting the strings." IOW, I lift them until they are level. I am always conservative in my pull, so that every string could be pulled more if need be. Once this has been done, mating hammers becomes a very fast job, that doesn't involve custom sculpting of the crown of each hammer to its strings - which I consider to be a very bad idea. As for permanence, I have touched up pianos that I did years ago, and the inconsistencies I have found are almost always ones I can't correct - that I probably couldn't correct when I leveled them before, because the strings had been over-pulled.

    A lot of people lift strings with far too much force. Use of the "Strate-mate" tends to urge you to apply more pressure that should be applied, and I know that many who do not use that leveraging tool also apply too much force (IMO), whether pulling from above or pushing from below. Once the termination bends have been maxed out, it can be near impossible to get the unison level. And the Strate-Mate does not make unisons anywhere near level in my experience, too much wobble.

    As for technique, I have often posted photos of my own homemade tool, but perhaps not on Pianotech. Here it is, pretty self-explanatory. Brass square stock on the bottom, two layers because I needed that much weight. A couple 1/8" brass rods to extend upward, so the level clears the capo or plate strut. A pocket level attached via a small piece of wood. Get it level, shoot with CA. I made two of these about ten years ago, and have used them happily ever since. 

    The technique requires that the level be very lightly steadied with finger and thumb of one hand, while the other plucks the strings to check. Otherwise, it will rock with the vibrations of the string, and you'll get a false reading. The plucker is also the puller (made of round brass stock, a music wire hook). Tool stays in the same hand, for maximum efficiency. The Goss tool is OK, but it is very short, hard to see, and hard to get fingers down to steady it. It also won't do the unison next to the strut, which tends to be the one that needs it the most. 




    ------------------------------
    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
    ------------------------------



  • 9.  RE: String leveling

    Posted 12-08-2017 09:41
    The wire/brass rod tool is great. But I ditched the level. Cumbersome and what's the reference, the crooked floor, the compound angled odd shaped string frame? etc etc.  Use these tools to get close, then work on the mating of hammers and string to get a little closer. Then a automated "pounder" to seal the deal.
    -chris
    #caveman

    ------------------------------
    The caveman sits as he watches the herd,
    His belly growls in hunger for what he sees.
    The mammoth aware blows his mighty trumpet,
    By fire tonight the caveman tickles the ivories.

    chernobieffpiano.com
    865-986-7720
    ------------------------------



  • 10.  RE: String leveling

    Registered Piano Technician
    Posted 12-08-2017 14:13
    Chris wrote:
    "I ditched the level. Cumbersome and what's the reference, the crooked floor, the compound angled odd shaped string frame? etc etc."

    As I have posted previously on this list, the reference is the key bed, which is why we take a few minutes to first level the piano (with the aid of a "jack-in-the-box, as measured from the 
    key bed, with a 48" carpenter's level). We square hammers to the strings (AKA "burning the shanks"), we travel the hammers so they are moving straight up and down, and we do many other things in pursuit of what Chris Brown has so aptly dubbed our "aspiration to verticality." Verticality relative to what? The surface upon which the action rests: The key bed.

    Perfectly leveled strings are not always possible. The strings of a unison being planar is more important than the unison being level.

    Alan

    ------------------------------
    Alan Eder, RPT
    Herb Alpert School of Music
    California Institute of the Arts
    Valencia, CA
    661.904.6483
    ------------------------------



  • 11.  RE: String leveling

    Registered Piano Technician
    Posted 12-08-2017 19:33
    I work on a fair number of high quality/high dollar instruments with the agraffes installed on an angle not perpendicular to the keybed or to the macro plane of the strings. I is my feeling that attempting to make the strings constrained by these agraffes level to anything other that the top of the agraffe is a mistake. Put the three strings of the unison in a plane then fit the hammers to the string. If one worries that the parts will suffer excessive wear then spend the time one saves not doing excessive leveling on practicing flange re-bushing.

    ------------------------------
    Karl Roeder
    Pompano Beach FL
    ------------------------------



  • 12.  RE: String leveling

    Registered Piano Technician
    Posted 12-11-2017 21:37
    It can be very interesting to run a string level along the string, first from the agraffe to the strike point (or just in front of the damper head), then from the back of the damper head to the bridge pins. There is a lot of chaos there, and the one thing you can be certain of is uncertainty/inconsistency. The strings are often tilted one way at the agraffe, and the opposite way at the bridge.

    I have a strong preference for leveling strings at the strike point for very practical reasons. If you file your hammers to a very straight line of crowns, and your strings are in a line with one another, your first mating will go much faster, and your subsequent matings will also go faster: just be very careful to file your crowns in a straight line. 

    I don't see why so many people over think this. It is simple geometry, and the fastest way to get good voicing results. Personally, I don't level the piano, unless there is reason to believe it is seriously out of level (brick or flagstone floors, for instance). I'll put my level on top of the stretcher, and if it is pretty close, I call it good enough and get to work. 

    If you custom fit hammers to strings that aren't in a plane, your una corda voicing will sound awful for the simple reason that the hammers will necessarily be unmated in shift position, probably worse than if you had done nothing. If they are in a slanted plane, that won't happen, but it will mean that you have to custom file a number of hammers to a slant, which is time consuming.

    ------------------------------
    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
    ------------------------------



  • 13.  RE: String leveling

    Posted 12-11-2017 21:52
    <If they are in a slanted plane...

    Had a vintage Bechstein rebuild like this. 88 agraffes...every last one of them slanted...however the sucker sounded quite nice, but every step of the way was brutal.

    Completely agree with your point about leveling for efficiency, and also the importance of leveling the hammers set to a straight line. I would add, with the hammers supported at strike for the filing.

    Also, in terms of efficiency, when restringing, I have noticed I have less work to do when I pre-bend the wires with parallel residual curves as I show in my last month's journal article. This, i assume because, the wire's residual curve's are all coming off the termination in a reasonably similar orientation.        


    ------------------------------
    Jim Ialeggio
    grandpianosolutions.com
    Shirley, MA
    978 425-9026
    ------------------------------



  • 14.  RE: String leveling

    Registered Piano Technician
    Posted 12-12-2017 23:19
    I've long had the same thoughts as Jim, that string leveling on pianos already in service is a waste of time because it's impossible to do on most unisons, and even if you can get some of them level, it doesn't last very long.  I think leveling IS worth doing immediately after a piano is strung or re-strung, but once they take a set they don't want to move.   

    I also share Fred's concern that mating hammers to un-level strings by sanding portions of hammer tops sabotages shift voicing, but think there's a way around this; see my article in the Tips Tools & Techniques column of the July  2017 PTG Journal.  If involves using diamond riffler files to remove felt only from the string grooves, not disturbing the nice flat top of the hammer.  I've been using this method with great success for several years.

    ------------------------------
    Larry Lobel RPT
    San Francisco chapter
    ------------------------------