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Baldwin Hamilton - one "string" drops suddenly in pitch, but not on test blows

  • 1.  Baldwin Hamilton - one "string" drops suddenly in pitch, but not on test blows

    Registered Piano Technician
    Posted 13 days ago
    I am calling this piano a Baldwin Hamilton because that's what I know it as. Label is Baldwin, but I've always thought of the "flip top" studio pianos (with built in lid prop) as Baldwin Hamilton.

    Anyway, I tuned this piano once 3 years ago, did 30-50 cent pitch raise, no issues. However at that time no one was really playing the piano. Now the owner is taking lessons and practicing every day.

    Tuned the piano 2 weeks ago and almost immediately the owner emailed me to say one note was very out of tune. I was out of town then but went to see the piano the day I returned (2 days ago) and one "string" of the three strings on the F# just before the treble break had dropped VERY noticeably. I thought maybe I had committed some terrible oversight and left it that way when I tuned it but owner said it was perfectly in tune when she first sat down to play it, but quickly went out of tune.

    Weird. Piano is in perfect like-new condition. Hammers barely worn, tuning pins SUPER tight like a new piano. I am extremely rigorous with test blows. (Passed my PTG tuning exam at over 90% with entirely aural tuning back in the '80s.)

    So I pulled up the middle string, whacked it hard with a bunch of test blows. Nothing changed, and I told the owner I had no idea what had caused the string to drop and that I have never encountered this before (which is true). I had no theory, but told her to let me know if it happened again. She texted me that night and said the note went out of tune shortly after I left.

    The owner is a woman of about my age (73) and is the only one playing the piano. She is definitely not a pounder, plus I DID pound it and nothing happened!

    Went back yesterday. Only possible thing I could think of was that no matter how hard I pounded my test blows, the string was getting "hung up" with friction somewhere. The weird thing is, why only on that half of the wire? The middle "string" is the same wire as the right "string", but right string is unaffected!

    On that theory (friction somewhere along the string) I took the action out to see if there was any obvious problem (no), dropped a little ProLube at all the bearing points. In doing so I noticed that at the hitch pin end, the strings all rise up sharply from the hitch pin and run across a sort of high bearing point on the plate - a  plate that is not smooth but very bumpy/rough finish - before reaching the bridge. Also, each hitch pin goes thru a hole in the plate and it seems to me the string kind of gets pulled around the hitch pin and down into the recess of the hole - an opportunity for a lot of the string to bind. Put lube there too.

    Then pulled up the string, set the pin, pounded like crazy. Told her if it happened again, I would post it to the forum.

    She texted me and said she sat down to practice and about 15 minutes after I left the string dropped again.

    My next attempt at a solution will be to replace the string. And lube all bearing points before putting the string on.

    But before I do that, maybe there is an Baldwin dealer of yore out there who has encountered this kind of thing who can offer advice. I used to do warranty and warehouse tunings for Baldwin in Chicago in the '80s, so it's not like I never tuned a Baldwin piano.

    Any other suggestions?

    Barb

    ------------------------------
    Barbara Barasa
    Ashland OR
    541-552-9349
    ------------------------------


  • 2.  RE: Baldwin Hamilton - one "string" drops suddenly in pitch, but not on test blows

    Registered Piano Technician
    Posted 13 days ago
    Barb

    Your explanation of what's going on at the hitch pin might be the cause of the problem.  It sounds like the string is not down in the plate at the hitch pin.  With a brass rod of some sort tap the string down on both sides of the hitch pin.

    ------------------------------
    Willem "Wim" Blees, RPT
    Mililani, HI 96789
    ------------------------------



  • 3.  RE: Baldwin Hamilton - one "string" drops suddenly in pitch, but not on test blows

    Registered Piano Technician
    Posted 12 days ago
    I'm think that there's a crack in plate - probably in the strut next to the note in question. I have a Kawai that does the same thing. I pointed it out to the owners, and they are fine with it now, because they understand that it's the piano, not me.

    Next time you're there, check it over for a crack and let us know. Best of luck,

    ------------------------------
    Benjamin Sanchez, RPT
    Piano Technician / Artisan
    (805) 315-8050
    www.professional-piano-services.com
    ------------------------------



  • 4.  RE: Baldwin Hamilton - one "string" drops suddenly in pitch, but not on test blows

    Member
    Posted 12 days ago
    There might be a weak spot in that length of wire and it's getting ready to break. The coil might not be tight around the pin. Use parallel pliers to squeeze in the becket and rotate while squeezing counter-clockwise a quarter turn or so to coax the wire around the pin; four times. The tension can drop anywhere from 10c to a minor third.

    ------------------------------
    Regards,

    Jon Page
    mailto:jonpage@pianocapecod.com
    http://www.pianocapecod.com
    ------------------------------



  • 5.  RE: Baldwin Hamilton - one "string" drops suddenly in pitch, but not on test blows

    Registered Piano Technician
    Posted 12 days ago
    I would say it is what Jon Page has said, or that the becket is slipping out of the tuning pin.

    I.e., during installation, it was only part way through the hole. You won't be able to see this while the string is under tension. Everything looks normal, and it seems to tune OK with test blows. Then it slips out, and goes wildly out of tune.

    ------------------------------
    John Formsma, RPT
    New Albany MS
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  • 6.  RE: Baldwin Hamilton - one "string" drops suddenly in pitch, but not on test blows

    Member
    Posted 12 days ago
    If the becket is slipping out, change the wire. To check for this, place a bend in a segment of music wire and insert it into the hole, this will indicate if the wire is insufficiently in the hole.

    ------------------------------
    Regards,

    Jon Page
    mailto:jonpage@pianocapecod.com
    http://www.pianocapecod.com
    ------------------------------



  • 7.  RE: Baldwin Hamilton - one "string" drops suddenly in pitch, but not on test blows

    Registered Piano Technician
    Posted 11 days ago
    I'm with John F on this. Sounds like wire slipping out of the pin.  Unless it's one of the Baldwin's with the bent length sticking out the other side of the pin opposite the becket. 





  • 8.  RE: Baldwin Hamilton - one "string" drops suddenly in pitch, but not on test blows

    Posted 12 days ago
    If it's the pin slipping use thin fresh CA down the side of the pin.

    There might also be a problem with the one of the bridge pins.

    Best wishes

    David P

    --
    - - - - - - - - - - - - - - - - - - - - - - - -
    David Pinnegar, B.Sc., A.R.C.S.
    - - - - - - - - - - - - - - - - - - - - - - - -
    +44 1342 850594





  • 9.  RE: Baldwin Hamilton - one "string" drops suddenly in pitch, but not on test blows

    Member
    Posted 12 days ago
    Check the bridge pins for that string. See if there are cracks that might be effecting that string's bridge pins.

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



  • 10.  RE: Baldwin Hamilton - one "string" drops suddenly in pitch, but not on test blows

    Registered Piano Technician
    Posted 12 days ago
    It is also possible that there is just enough friction to make that condition, when pitch is approached from above. I have experienced this many times, with strings that have tight tuning pins, beckets that are just fine, no really excessive friction. From those experiences I have learned to pay very close attention to how the tuning pin and string move in the final approach to pitch. Paying close attention, I will find that there are problematic strings/pins that don't want to be placed "just so" exactly where I want them, and that I can ease them into tune from above, BUT I will have moved the pin in the block more than the string will have moved in pitch. My solution is to tune in the sharp direction, which is, unfortunately, complex to explain. If you care to read the details, they are here. The short version is that I won't leave a string pin that has been tuned in the downward direction unless I can flex the pin and have the pitch go down, flex it the other way and have the pitch go up. And that, when in doubt, always tune upward, as pitch will never be as unstable in the sharp direction as it will be in the flat direction.

    The lowest tenor strings are troublesome because they are so low in tension, and such a little change causes a big pitch move.

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



  • 11.  RE: Baldwin Hamilton - one "string" drops suddenly in pitch, but not on test blows

    Member
    Posted 12 days ago
    To Fred's point, the best description I've heard of the tuning process (hammer technique) is that tuning is an ever diminishing series of moving the tension sharp and flat of pitch to get a feel for the torsion in the pin. With the last motion a slight nudge sharp to bring to pitch (less than a cent).
    This will leave the wire segment between the pin and counter bearing (Non Speaking Length - NSL)  a little higher in tension than the speaking length (SL). If you were to come down to pitch and leave it, the NSL will be lower in tension and a sharp blow will allow the lower tension to ease into the SL. The friction at the bearing points allows the higher tension to remain while the lower tension allows for slippage.

    Because of the friction, the tension in the NSL increases before the SL when pulling tension upwards. When lowering tension, the NSL lowers in tension before the SL does. Which is why it's a good habit to lower tension slightly first before raising the tension. This breaks the friction which could cause the string to break if it didn't release before the string's breaking point is reached.

    The tighter the hold of the block, the more torsion is imparted to the pin. So careful manipulation is paramount to stabilization. A Counter Bearing Lube reduces the drag/friction and allows for easier tuning from less pin twist/torsion.

    ------------------------------
    Regards,

    Jon Page
    mailto:jonpage@pianocapecod.com
    http://www.pianocapecod.com
    ------------------------------



  • 12.  RE: Baldwin Hamilton - one "string" drops suddenly in pitch, but not on test blows

    Registered Piano Technician
    Posted 12 days ago
    It isn't that unusual for "test blows" to fail to actually settle the pitch where it will go eventually. The experience that inspired me to "get religion" on stability is a case in point. There was a particular string, C5 or C#5 or so, right above the break on a Steinway A, that consistently went south about 10¢ or so. This was a instrument at a jazz venue, which I tuned maybe 40 times a year, and which I had restrung. Pins were plenty tight, strings not that old. 

    Eventually, word got to me that audience members were noticing and wondering if that couldn't be fixed. In fact, a customer of mine, who didn't know I tuned the instrument, commented to me about it. IOW, it was getting embarrassing. 

    I started by pounding the heck out of that note. Symptom recurred. So I began honing in on what was going on. I noticed that when I was raising pitch, the pin didn't want to go that last little bit. It always wanted to shoot past, which put the pitch unacceptably sharp. So I would approach from above, and could ease it right into perfect tune. Except that while I was moving it flat, I was moving the pin in the block without the string and pitch following, enough to account for what happened later.

    The only real fix is to put the pin where it needs to be, no ifs ands or buts about it. But how can you know where it needs to be? You can only really know by feeling the pin move in the block and comparing that with how and when the pitch is changing. The solution in this case was to approach from below, and really fuss to be able to make that last little bit of pin movement to the right alignment: just the right amount of torque over what is holding the pin in the block, controlled so the pin moves the slightest bit. Also needed was the ability to do this without making the string go sharp over the bearing points, because there was enough friction that flexing/twisting the pin in the flat direction wouldn't get the string to go flat and get to a stable point. So I flexed the pin flat while rotating it sharp - pin moves in block, no pitch change - then flex the pin sharp with little nudges to just get it to make it to pitch.

    This situation is actually quite common, as I found over time, and using an ETD is by far the best way to deal with it. I can see the tiniest change in pitch before I can hear it, so I know at all times whether and how much the string is moving. One useful technique is to play it fairly loudly with a regular pulse (2 a second or so), and observe pitch movement if any. If it is starting to go flat of target, nudge the pin in a sharp direction, and vice versa. You can see whether there is good rending of the string over friction points, and if there is not, you can adjust accordingly. 

    I hope the above may be useful to some who are reading it.
    "Believe those who seek the truth; doubt those who find it; doubt everything but yourself." Gide






  • 13.  RE: Baldwin Hamilton - one "string" drops suddenly in pitch, but not on test blows

    Member
    Posted 12 days ago
    If you have proper hammer technique, a test blow is unnecessary. Rapid mf blows excite the wire enough to settle the pitch.

    Even if you pull the string to pitch and leave it, the NSL will be lower in tension due to the torsion release in the pin. Be very mindful of the tension left in the NSL.

    ------------------------------
    Regards,

    Jon Page
    mailto:jonpage@pianocapecod.com
    http://www.pianocapecod.com
    ------------------------------



  • 14.  RE: Baldwin Hamilton - one "string" drops suddenly in pitch, but not on test blows

    Registered Piano Technician
    Posted 12 days ago
    If you are flexing the pin in the flat direction while pulling sharp (to counteract pitch change caused by pin twisting), enough so that when the pin begins to move in the block the pitch begins to change, then, when you have reached the target, the untwisting of the pin and the release of the flex with balance one another, and the pin and string will be left in a stable condition.
    Regards,
    Fred Sturm
    "A mind is not a vessel to be filled, but a fire to be kindled." Plutarch






  • 15.  RE: Baldwin Hamilton - one "string" drops suddenly in pitch, but not on test blows

    Member
    Posted 12 days ago
    I don't recommend pin bending unless needed as a last resort in a certain isolated instance.  I can always tell while trying to tune a piano that the last tuner was a pin bender. Makes me shutter just to think about it. It takes a couple tunings to reverse that poor hammer technique condition.

    ------------------------------
    Regards,

    Jon Page
    mailto:jonpage@pianocapecod.com
    http://www.pianocapecod.com
    ------------------------------



  • 16.  RE: Baldwin Hamilton - one "string" drops suddenly in pitch, but not on test blows

    Registered Piano Technician
    Posted 12 days ago
    Pin "bending" means that the pin has been flexed past its elastic limit. Definitely should never be done. Pin flexing happens regardless, unless you use a T hammer or one of Dan Levitan's C hammers. Use of a lever will cause flex at a right angle to the lever.

    Shudder away, but my flexing technique has caused zero negative ramifications, including on concert grands I have tuned several hundred times. Stability is excellent, by observation of the pianos next day, next week, next month, etc. Mind you, the devil is in the precise details of how you go about it. 
    Regards,
    Fred Sturm
    "I am only interested in music that is better than it can be played." Schnabel






  • 17.  RE: Baldwin Hamilton - one "string" drops suddenly in pitch, but not on test blows

    Posted 12 days ago
    On some instruments which are difficult to fine tune or which slip, I've found it helpful to take the pitch low momentarily so that the whole string is moving at every point and whilst vibrating pull the string right up to pitch in one move and leave it there. This is possible with an ETD and one has to be quite deft but the technique works.

    On an allied subject, I've had a couple of instruments, one in particular where the pins have been effectively locked into the wrest plank and nearly don't rotate at all. I think it was possibly due to dryness during the summer but turning the pins simply resulted in torsional stress and I was worried about breaking them. The result has been more of a balance between torsion and pin wobble, leaving a very unstable tuning.

    Best wishes

    David P

    --
    - - - - - - - - - - - - - - - - - - - - - - - -
    David Pinnegar, B.Sc., A.R.C.S.
    - - - - - - - - - - - - - - - - - - - - - - - -
    +44 1342 850594





  • 18.  RE: Baldwin Hamilton - one "string" drops suddenly in pitch, but not on test blows

    Registered Piano Technician
    Posted 12 days ago
    One of the great things about problems as mysterious as this one is that we see so many methods and thought processes articulated in depth.
    While tuning pin manipulation might solve the symptom, it's secondary to whatever the actual problem is, but often that's the best one can do.
    Baldwin made seemingly no effort to dress the terminal points on its vertical plates, the roughness is certainly suspect. The F#5 is the last note in the middle section so every point of contact with the strings bears close inspection. The V-bar hasn't been mentioned and it's worth a look also, it might be worth backing the end screw off enough to make sure that the screw shaft isn't broken and then cinching it up again. Also, that note is right next to the notch in the bridge, in addition to inspecting the bridge pins and maybe tapping them in a little (if the keybed isn't in the way), I'd take a look at the bridge cap, checking for separation.
    That the middle string is the one with the problem and not the string on the end adds to the mystery. I think the most likely culprit is the string is binding or is pinched at the hitch pin. When replacing the string I'd come prepared to smooth the surface of the hitch pin, if there's a void at the base of the pin and the plate, perhaps have some epoxy putty to fill the void and then use a felt punching on the hitch pin. Also when the strings are removed, if any good can be done smoothing out the other points of contact with the plate it would be worth the effort. Actually I'm not sure how the bridge pin would account for the pitch dropping but there are many segments between the two strings where there could be a disparity in the tension.
    I hope this mystery gets resolved conclusively.

    ------------------------------
    Steven Rosenthal
    Honolulu HI
    808-521-7129
    ------------------------------



  • 19.  RE: Baldwin Hamilton - one "string" drops suddenly in pitch, but not on test blows

    Member
    Posted 12 days ago
    another thought...check to see that the middle string is not contacting one of the pressure bar screws, creating a high friction point in addition to other high friction points.

    When going back to fix the dropped string, even though the pitch dropped, the pin position is already pretty close to target. Just rotate the pin up in the block a smidge, without trying to hear and test where the pitch went...just rotate the pin up. If the pitch doesn't follow, which is probably the case, without rotating the pin further, ease it the pitch with pin flex, and leave it.

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



  • 20.  RE: Baldwin Hamilton - one "string" drops suddenly in pitch, but not on test blows

    Posted 12 days ago
    This might not be acceptable to all, but we've had some problems with certain models of Yamaha recently which are similar to what you describe.  We have found that lowering the pitch on all of the unisons in that area then bringing them back to pitch seems to resolve the issue.  Just an idea is all.  It works in our little world here once in a while.

    ------------------------------
    Ted Rohde
    Central Illinois
    ------------------------------



  • 21.  RE: Baldwin Hamilton - one "string" drops suddenly in pitch, but not on test blows

    Registered Piano Technician
    Posted 12 days ago
    Ted, that's fascinating. 2 questions. How far do you drop the pitch and why do you think that works?

    ------------------------------
    Steven Rosenthal
    Honolulu HI
    808-521-7129
    ------------------------------



  • 22.  RE: Baldwin Hamilton - one "string" drops suddenly in pitch, but not on test blows

    Posted 11 days ago
    Steve,  In our cases, the pitch would drop around 80-90 cents on certain strings usually near the bottom side of treble break.  We drop the pitch until the strings are loose then bring them back up which has solved the problem in all of our cases.  As in the case presented here, no amount of seating nor hard striking would make the strings drop...only a little time.  In all of our cases, there was no perceptible movement of the wire out of the beckets. The next time we run across it, I'll have the tech remove the action and video the process so we can watch what it does to the strings in process.  The loosening of the wires was something that was shown to me by a Yamaha field tech.  It definitely solves a specific problem.

    ------------------------------
    Ted Rohde
    Central Illinois
    ------------------------------



  • 23.  RE: Baldwin Hamilton - one "string" drops suddenly in pitch, but not on test blows

    Posted 10 days ago
    What is pin-flex? Is this an answer to impossibly tight pins?

    Many thanks

    David P

    --
    - - - - - - - - - - - - - - - - - - - - - - - -
    David Pinnegar, B.Sc., A.R.C.S.
    - - - - - - - - - - - - - - - - - - - - - - - -
    +44 1342 850594





  • 24.  RE: Baldwin Hamilton - one "string" drops suddenly in pitch, but not on test blows

    Registered Piano Technician
    Posted 11 days ago
    I had this situation happen quite a few times, and at first  it was a head-scratcher, until I figured out the underlining issue. The symptoms were the unison would  get tuned  cleanly, and but 10 mins later, the pitch on string would drop a good 100 cents.
    If it is what I think it is, you might have a situation where the string is literally cutting its way into the pin. Take the tension down remove the string off the tuning pin.  When looking at the pin, see if the hole has  become very oblong, especially when comparing to the becket on the other side of the pin. If this is the case, I'm 100% sure this is your smoking gun.  You'll notice 2 things; the string has cut marks on the sharp bend of the coil where it goes into the becket, and the tuning pin becket hole will have become oblong.  Thus you have 2 surfaces that have become weak ( the pin and string) and that's whats causing the drastic drop in pitch. If this is the case, you can be rest  assured that the fix is just minutes away.
    The quick fix is to remove the string coil off of the tuning pin. Snap the tail of the coil off, create another coil tail that will be your new tail portion that goes back into the becket. Reinstall the coil onto the pin using the other side the becket, and then proceed.  If you want peace of mind, replace the tuning pin altogether.  If this is a larger wire sized string, it can be tricky  creating another tail  as the string can be very stiff and difficult to manage. In these cases, I usually take a screw driver and insert into the coil and with good arm leverage, you can pull the coil straight, or at least somewhat straight.  With stiffer strings its easier to create coil tail by creating a new coil altogether.  The bottom line is that if everything goes smoothly, you can have the pitch of the string up and holding  in no time. And it will hold as well as the neighboring strings.  In all of my cases, no new strings were ever needed and I was able to get 100% stability without any more followup.  Give it a try.

    ------------------------------
    Tom Servinsky
    ------------------------------



  • 25.  RE: Baldwin Hamilton - one "string" drops suddenly in pitch, but not on test blows

    Registered Piano Technician
    Posted 11 days ago
    Tom,

    Thanks for your post. It taught me both about a possible solution to the problem stated in the OP, and that I need to review my usage of certain nomenclature.

    So, the becket is the hole in the tuning pin, and the straight part of the wire that goes through the becket is the tail? And so-called "becket- breakers" are a misnomer?

    Seeking clarity (as always!),

    Alan

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



  • 26.  RE: Baldwin Hamilton - one "string" drops suddenly in pitch, but not on test blows

    Registered Piano Technician
    Posted 11 days ago
    What a fun problem. Well, fun for us who get to speculate.

    Great description of pin "flexing" by Fred. The problem he described seems likely. I think of it as the tuning pin "wanting" to settle in a position that, if the tensions across string segments were equalized, would be out of tune; while the string "wants" to settle in a place that is in-tune and is willing to endure unequal tensions in its segments to sit there for as long as it can. If this is the problem perhaps you will find a solution in tapping down the coils on the tuning pin or adjusting the string position on the hitch pin, both of which would "reset" things a bit by making it so the tuning pin needs to be in a different position to be in tune.

    I could also see this being a small crack in the bridge that allows one of the bridge pins to move from side to side.

    ------------------------------
    Anthony Willey, RPT
    http://willeypianotuning.com
    http://pianometer.com
    ------------------------------



  • 27.  RE: Baldwin Hamilton - one "string" drops suddenly in pitch, but not on test blows

    Registered Piano Technician
    Posted 11 days ago
    Alan
    Good point.  I guess I labeled it backwards. <grin>    But you get the gist

    ------------------------------
    Tom Servinsky
    ------------------------------



  • 28.  RE: Baldwin Hamilton - one "string" drops suddenly in pitch, but not on test blows

    Registered Piano Technician
    Posted 11 days ago
    Two more possibilities
    I did have this issue with a Hamilton
    A hitch pin flexing that eventually broke
    Second, and I submit this with all due respect, I would look in the bench for a tuning hammer

    ------------------------------
    S. Fenton Murray
    Royal Oaks CA

    S. Fenton
    ------------------------------



  • 29.  RE: Baldwin Hamilton - one "string" drops suddenly in pitch, but not on test blows

    Registered Piano Technician
    Posted 10 days ago
    Just to clarify, this is how my experiences led me to considering the tuning pin as a possible culprit. Several years ago I had restrung a Kawai KG2  for a local theatre.  My coils are usually extremely tight and clean, with ample tail going into the tuning pin. Never do leave the becket hanging with any gap between the string and pin. And I do ample settling of the strings to get the piano to very stable level of tuning.  When I doing the weekly tunings, I started noticing a strange behavior,with one string (at time) falling extremely flat. At first, I thought it was an isolated string settling more. But after settling the strings extremely well, bring it up to pitch, and then to have this same issue happen over and over again, something else was contributing to this issue.   Each time after the pitch  was brought upseveral times, the string would continue have a rapid pitch drop, probably within 15 mins.  Eventually the string would break at the becket. Keep in mind, these were new strings.  When I replaced or repaired the string ( making a new becket), got it settled, the same rapid behavior continued to happen (using the same pin and same hole). That's when I started to take a closer look as to what other factors could be at play. Upon inspection of the tuning pin, I started to notice a clear groove being cut into the tuning pin.  The tuning metal appeared to be weak enough that the string was actually cutting the pin. Once  the groove got advanced enough, that's when the first signs of the pitch drop would occur. The groove started cutting the string like a dull guillotine, first weakening the string, then eventually breaking at the becket.  So between the 2 surfaces failing, my theory was the culprit was a soft spot in the tuning pin. This was not strings stretching. This was string weakening.
     Resolve:
    Once that I either replaced the pin and repaired the string, or did the string repair and kept the pin (only using the other side of the pin), the problems went away immediately. No more pitch drop and the string held extremely well. Never did the problem reoccur with that same note. Through that batch, I bet there were several dozen that had the the same issue over 2 yrs. Since then, I've seen this same issue raise its ugly head on other pianos. I'm not saying that this applies to the original author's thread, but its well worth adding this possibility to your bag of tricks. If it is what I've laid out, its a relatively easy resolve.

    ------------------------------
    Tom Servinsky
    ------------------------------



  • 30.  RE: Baldwin Hamilton - one "string" drops suddenly in pitch, but not on test blows

    Registered Piano Technician
    Posted 11 days ago

    My vote goes to the becket slipping. Classic symptoms. If it was the hitch pin then the sister unison would be moving as well. Strings don't start to stretch before breaking, so that's out. Bridge pin migrating is a maybe but easy to rule out by visual inspection. Either change the string or cut the becket off and reinsert making sure there is a slight protrusion. Either way you're coming back again to tweak the tuning, probably a couple of times. 

    Re Fred's comments about pin flexing, totally agree with that method, we've discussed it before.  It minimizes pitch movement and flexing counteracts twisting. On uprights tuning from the 2:00 position accomplishes that naturally. On a grand you would have to tune from the 7:00 position which is awkward ergonomically so a gentle pressing of the hammer handle down toward the string from the 2:00 position accomplishes the same thing. 



    ------------------------------
    David Love RPT
    www.davidlovepianos.com
    davidlovepianos@comcast.net
    415 407 8320
    ------------------------------



  • 31.  RE: Baldwin Hamilton - one "string" drops suddenly in pitch, but not on test blows

    Registered Piano Technician
    Posted 11 days ago
    Maybe not often but I did have a string stretch and get visibly thinner before it broke. PSO.

    ------------------------------
    Larry Messerly, RPT
    Bringing Harmony to Homes
    www.lacrossepianotuning.com
    ljmesserly@gmail.com
    928-899-7292
    ------------------------------



  • 32.  RE: Baldwin Hamilton - one "string" drops suddenly in pitch, but not on test blows

    Registered Piano Technician
    Posted 10 days ago
    I have not seen it, but often, once it breaks, I realize that I felt it. Tightening the string without any pitch response for a few times, not consistently with the other strings, then pop.

    ------------------------------
    Cindy Strehlow, RPT
    Urbana, IL
    ------------------------------



  • 33.  RE: Baldwin Hamilton - one "string" drops suddenly in pitch, but not on test blows

    Registered Piano Technician
    Posted 9 days ago

    Tightening the string without any pitch response means that the string is hanging up at the bearing points. Since the segment from tuning pin to bearing points (capo bar, countering bar in front duplex, etc) is so short it doesn't take much of an attempt to raise the pitch to push that segment past the break point. That is a common reason for breaking stings while tuning. 



    ------------------------------
    David Love RPT
    www.davidlovepianos.com
    davidlovepianos@comcast.net
    415 407 8320
    ------------------------------



  • 34.  RE: Baldwin Hamilton - one "string" drops suddenly in pitch, but not on test blows

    Registered Piano Technician
    Posted 10 days ago
    I beg to differ with David! I don’t know if it was “stretching”, per se, but I’ve experienced coming across a wildly out-of-tune string on a piano I’ve tuned before, and with manipulation or test blows, it gives up the ghost. Mostly top treble. Of course, this would not account for the scenario under discussion - the phenomenon doesn’t happen multiple times- but...something happens!
    Best,
    Linda Scott

    Sent from my iPhone




  • 35.  RE: Baldwin Hamilton - one "string" drops suddenly in pitch, but not on test blows

    Registered Piano Technician
    Posted 10 days ago
    It's not string stretching. Piano wire doesn't thin out over time under tension and go flat because of it. Nor does it start to develop a weak segment that starts to "thin" eventually breaking.

    ------------------------------
    David Love RPT
    www.davidlovepianos.com
    davidlovepianos@comcast.net
    415 407 8320
    ------------------------------



  • 36.  RE: Baldwin Hamilton - one "string" drops suddenly in pitch, but not on test blows

    Registered Piano Technician
    Posted 9 days ago

    The issue of strings stretching can be understood in terms of elastic versus plastic deformation. Deformation occurs when materials are put under stress. Elastic deformation means that the material will return to its original form after the stress is removed. Plastic deformation means that the material has been stressed beyond the yield point where the atomic bonds of the material are altered. When the stress is removed the material does not return to its original form. All materials have a yield point: tuning pins, strings, plates, ribs, etc. In the case of strings, pulling the string to tension or even beyond the required tension to a degree does not reach the yield point where the string will undergo plastic deformation, or, re this discussion, start to stretch which would both alter the yield point and the break point (or point where deformation leads to failure). Strings will not, under normal tension, deform over time. The designed tension of strings is always under the yield point. 


    Things can happen to weaken the strings, for example corrosion, wire fatigue due to friction, etc. And strings can be pulled past the yield and break point in the process of tuning (or playing) for a variety of reasons. But the strings left on their own at tension below the yield point will not simply start to elongate and thin (undergo plastic deformation) leading to ultimate failure. 



    ------------------------------
    David Love RPT
    www.davidlovepianos.com
    davidlovepianos@comcast.net
    415 407 8320
    ------------------------------



  • 37.  RE: Baldwin Hamilton - one "string" drops suddenly in pitch, but not on test blows

    Registered Piano Technician
    Posted 10 days ago
    If it is the becket slipping, that is easy to diagnose, as Jon Page pointed out. First, look at the actual bend coming out of the hole in the pin: is it sharp, or rounded? (should be sharp). If you can't see the end of the becket bend in the other side of the hole, simply take a piece of music wire (any size, might as well be #13), make a bend in the end about becket length, Insert it in the open end of the becket hole in the pin. If it goes in, it can serve as a gauge to find out how much string is in the hole. (This assumes you can't get a good line of sight and simply look in the hole).

    If the gauge wire goes in any significant amount at all, Loosen the pin something close to a full turn and pull the becket bend out. You can see how long the tail of the bend is, and how sharp the bend is.

    Since this is lower tenor, it is less likely that this would be the problem, for a few reasons: the thickness of the wire is such that the bend is less able to travel along the string; the tension is relatively low on the string; and there is likely more friction between the string and the becket hole, as the diameters match more closely. Slippage happens more often in the upper treble, where the wire is much smaller than the hole and the tension is higher. It's not out of the question, just less likely. If a short amount of wire is inserted in the hole, and the bend is rounded, slippage can certainly occur in the tenor.

    Tom Servinsky's scenario is not one I've encountered. Good to know about as a possibility.

    The scenario I described, where it is a matter of tuning technique, can be diagnosed fairly simply. Twist and flex the pin in the flat direction without moving the pin in the block. Does the pitch go flat? If not, do the same and move the pin in the block a wee wit. Does the pitch go flat?

    If the answers are no, then you really need to tune that particular string/pin in the upward direction to get stability.

    Note that the various hitch pin theories don't apply because this is a single string, whose neighbor will share the hitch pin. If it were two neighboring strings, the hitch pin might come into play.
    Regards,
    Fred Sturm
    "The true sign of intelligence is not knowledge, but imagination." - Einstein






  • 38.  RE: Baldwin Hamilton - one "string" drops suddenly in pitch, but not on test blows

    Registered Piano Technician
    Posted 9 days ago
    Thank you all for tossing out your best ideas. So many responses, so little time!

    Photos at end of post.

    I apologize for any ambiguity when I said "note before treble break." It seems some people thought I meant the last note on the bass bridge. This piano has 3 sections of strings, and I refer to the strut between bass and treble bridges as the "tenor" break and the strut between middle section and higher treble as the "treble" break. Maybe that's not proper or consistent terminology and I should get my jargon straight.

    So to clarify, this was the top note in the "middle section" of the piano, right before the plate strut separating it from the high treble. And it was the middle string in that note that was dropping suddenly. So no, it was not a single, wound string.

    Also, I was always confused myself because people use becket to describe both the hole and the wire that goes into the hole. So I think now I'll use "tail" for the part of the wire that goes in the becket.

    I only mentioned my PTG test results in the first post because I had already ruled out "faulty hammer technique" in my mind as the culprit and that was the only way I could think of to justify ruling it out. Three years ago I did a 30-50 c (bass to treble) pitch raise on this piano, and a few weeks ago I did a 5-15 c pitch raise. All other strings on the piano were stable. No way I could blame it on poor hammer technique. And I really don't want to get into the whole bending, flexing, messing with tuning pin controversy. I was taught to set the pin (straighten it out because the part of the pin outside the hole twists, especially when pins are very tight - and this has been demonstrated to be true) and use firm test blows to even the tension among all the speaking and nonspeaking lengths of strings. It works for me. Any other theories or techniques ... I would want some engineer type to show me experiments that demonstrate how they work.

    Back to this Baldwin.

    I had already squeezed the wire against the pin, even tho the slight gap there was no more than on many other pins on this piano (which were not slipping).

    I had already checked to make sure no string was binding against a pressure bar screw, but the middle string COULDN'T be binding against that anyway.

    Of the theories I got as feedback, I considered the most likely suspects to be:

    1. Binding at the hitch pin (because of the plate being bumpy, the hole for the hitch pin being recessed, and there being a sharp upward rise of the string against a sort of V bar molded into the plate just above the hitch pin. The wire definitely could not ride up on the hitch pin (see photos).
    2. Tail of wire not long enough in the becket, and wire working its way out. However, I should have seen that gap at the becket get bigger if that was happening between visits, and I didn't. But still ... who knows?
    I liked the idea of filling the recess around the hitch pin hole in the plate with epoxy to try to keep the string from getting pulled into the recess, so I got some quick setting epoxy to take with. I borrowed back my stringing box, which I bequeathed to my "protege" a couple of years ago, so I would have the right tools and supplies whether just rejiggering existing string or replacing it.

    So on trip 4 (trip 1 was tuning a few weeks ago, then 2 more to pull up string) here is what I found and what I did. I will give my conclusions, such as they are, at the end.

    I backed out both tuning pins enough to pull wire off hitch pin. This required more than the usual backing out because the hitch pins had been bent down towards the plate at the factory. You can see this in some of the photos, and that the pins have been pounded down by a hammer. When I could see the hitch pin without the string around it I realized that, because of location of the hitch pin (sort of behind the keybed) and the pin being bent down, even if I used the end of an opened up jumbo paper clip to try to get epoxy around that hole, there was no way I could clean the epoxy up tidily and it might make a rougher surface than the plate already was. So I dropped that idea.

    Then I checked the bridge pins. Well, the top RIGHT bridge pin was completely loose. But that was not the string that was dropping in pitch! The other bridge pins on that note were all tight. But I epoxied that bridge pin in.

    After the expoxy set, I decided to try to keep the existing string, but put about a half turn more on one pin and a half turn less on the other, which would move the part of the string that might have been binding under the hitch pin over a little. At the suggestion of one of you, I put a thin balance rail felt punching on the hitch pin, also to try to prevent binding against the plate.

    I got the right tuning pin (not the problem string) turned some, pushing the tail back into the becket every time it started sliding out. Once I had the coils on that one tight enough to not slide around, I started on the middle tuning pin. And guess what? The tail of the wire had broken off when I was backing the pin out!! Was it too short? I don't know. Maybe it broke because I had to turn the pin so far counterclockwise. In retrospect, I should say that on this Baldwin, on some of the tuning pins the wire was obviously poking out the other side of the hole, but on this particular pin it was not. I didn't use a piece of wire from the open side to see how far the tail was in the becket, but I'll remember that idea in the future.

    At first I felt I would need to put a new string on. But I was not looking forward to going back to pull it up over and over. So I did something I've never done - I flattened out the end of the coiled wire, pushed it into the becket, and crimped it around the pin. I figured if it broke when I tightened the wire, I wouldn't be any the worse for it. It was worth a try. I was already not planning to have exactly 3 coils on each pin anyway, so what the heck?

    I made sure there was enough wire in the becket that I could feel it poking out the other end and that it didn't pull back as I worked on getting the coil tight, etc. Tuned up both strings and checked neighboring strings (still almost perfectly in tune).

    That was Thursday around 4:30 pm. After the last two attempts at just pulling up the string, the owner texted me within an hour saying the string had dropped significantly in pitch.

    The result this time: owner texted me Friday morning saying "So far so good" and hasn't contacted me since. (It is now Saturday night.)

    As a person who likes to know the "why" of everything, I know the scientific method would say make only one change at a time if you want to know which thing worked. I did not want to keep going back trying one idea each time so I did a couple of things and we don't know for sure which of them worked.

    Would the result have been the same if I had:
    just glued in the loose bridge pin, even tho the problem string was not against that pin?
    just lowered the strings but not so far as to take the string off the hitch pin and then just retuned, as the Yamaha person suggested?
    left out putting the felt punching at the hitch?
    not noticed or corrected the loose bridge pin?

    Sadly, we will never know. But I think the problem is corrected.

    As evidence that this piano was not Baldwin's finest hour, I include a photo showing a slathering of glue on top of the bridge in a totally different (higher treble) section of the piano, and a string on the note just above the treble break that shows notches in it from some kind of mishandling.



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    Barbara Barasa
    Ashland OR
    541-552-9349
    ------------------------------



  • 39.  RE: Baldwin Hamilton - one "string" drops suddenly in pitch, but not on test blows

    Registered Piano Technician
    Posted 8 days ago
    Barbara, those are really excellent photos, did you do that with your phone?
    Assuming pic #1 is the actual problem string, while the bend in the wire doesn't look too bad, it does look a little rounded and the bend isn't directly over the becket. Also, as the tail doesn't go all the way through and out on either of the pins it makes me wonder if ​it's not the original string. And then the string broke at the tail. All this would lead me to think that the tail is the prime suspect, the other defects are worth looking at but none of them would obviously cause the symptom. If it's not the original string, we can hope that it is at least the right wire size. I understand your reasoning but if it was me I would have replaced the wire for a host of reasons, it looks like it's going to hold now so that judgement is academic. Hopefully you won't hear back about that string. Yay.
    By the way, there is a two part epoxy putty that wouldn't run on you at all to fill a gap such as that in the plate. Also, for what it's worth, I have given up using quick set epoxy on anything, having had some critical failures. The T-88 quickset even says on the label that it is for temporary repairs. However you were just filling a gap in the bridge so I'm sure it's satisfactory.
    With regard to the other defects your photos revealed, I thinks it's more than not being Baldwin's finest hour, it was more like not their finest quarter century.
    Good job!

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    Steven Rosenthal
    Honolulu HI
    808-521-7129
    ------------------------------



  • 40.  RE: Baldwin Hamilton - one "string" drops suddenly in pitch, but not on test blows

    Registered Piano Technician
    Posted 8 days ago
    Re: epoxy -  I intended to use it to put in the recess of the hitch pin hole. I wasn't worried about it running - it was pretty thick. I just didn't think I could get it smooth enough where I would have put it because of the limited angles I had to work in, and I didn't want anything in that area that turned out to be rough. There was already plenty of that. I wasn't worried about a strong enough bond because I wasn't planning to use it to hold two parts together. And I think it was OK to use on the bridge pin instead.

    Yes, I took the photos with my phone. I've found that I can get photos of things I can't even see with my eyes because I can put the phone at an angle in tight spaces where my head won't go. There'll be a Tech Tip in the journal sometime about how I realized I could get the serial number off the tag on the back of a piano without pulling the piano more than an extra inch or two away from the wall - those pianos where that's the only place the serial number exists. Also, digital cameras (like in phones) are usually pretty great at adjusting automatically to how much light there is (or isn't). Of course, I'm looking for functional images, not artistic ones! So the benchmark is pretty low.

    I used to be a web designer (did the websites for many of the west coast regional conferences for years) so I know how to get decent photos AND get the file size of the photo way down for posting on the web. In most of those photos I took I set my iphone (not new, it's a 6) to hi res and always no flash and sometimes used my fingers to zoom in on what I wanted to get. Then when I transferred them to my computer, I used my old graphics editing software that I had from web design days to crop the photos to just the essential parts I wanted to show, reduce the image size (actual width and length in pixels) to what I wanted, and then if still necessary, reduce the file size of the resulting image while retaining good enough resolution. So photos that started out being 2 MB and too big in their full dimensions to even display on my monitor wound up being the image dimensions I wanted and maybe 60-150 KB each in filesize.

    That is a useful skill if you are putting photos into something like a Word doc or PowerPoint file, too. If you put 10 photos that are each 2 MB into a doc and THEN resize them within the doc (using the "handles"), you are not reducing the size of the image files at all. So you've then got a doc with 200 MB of images that you are trying to email to someone or open up in a slide show, where it could have been reduced to maybe 1 or 2 MB total.

    For print media, you want the biggest filesize and highest resolution you can get. For the web or for inserting in docs that will be emailed or displayed on a computer, you want the smallest filesize and lowest resolution that will still look good enough.

    ------------------------------
    Barbara Barasa
    Ashland OR
    541-552-9349
    ------------------------------