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new front keybushing clearances

  • 1.  new front keybushing clearances

    Member
    Posted 28 days ago
    We are trying to tighten up our clearances on new front bushings, relative to how much side to side movement is allowed. We tend to have about .010-.012" side to side play, and are playing with tightening that up, wth mixed results. Any comments on manufacturers new targert specs on front bushing side-to-side play?

    Most of what I can measure is close to that .010-.012-ish.

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


  • 2.  RE: new front keybushing clearances

    Registered Piano Technician
    Posted 28 days ago
    Jim,

    I've never actually measured this, other than by feel (although now you've got me curious how the measurement of my feel compares with yours...). I would describe this as a slight, but positive knock. We have been able to make the knock even slighter when using WNG front rail pins. Of course, when reducing the amount of play between key pin and bushing, it becomes more critical that the bushing is not too long, going too deep into the mortise.

    Alan

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



  • 3.  RE: new front keybushing clearances

    Registered Piano Technician
    Posted 28 days ago
    Jim-

    How are you measuring , exactly?

    ------------------------------
    David Brown
    Garland TX
    ------------------------------



  • 4.  RE: new front keybushing clearances

    Registered Piano Technician
    Posted 28 days ago
    One way is to take a file folder (which usually measures out at around .012) and cut a strip the width of the key mortice. If you can get the strip between the wood and the front rail pin, then you have .012 clearance. The main thing to watch for is that point where the key feels fine by itself, but may actually be sluggish when octaves are involved. Playing an octave pushes the two keys apart and can make one or both keys feel sluggish.  

    The other thing to consider is how slick the key pin and bushing felt are. I like the balance rail tolerance a little less that .012. But for that to work, bushings and pins need to be clean, lubed, tefloned, etc. Pushing the tolerances could get you in trouble if the key hesitates at all, or starts to hesitate as humidity changes in the room. The definition of safety margin is sacrificing the perfect for the sake of the good.   

    Richard West







  • 5.  RE: new front keybushing clearances

    Member
    Posted 27 days ago
    Measuring first by feel to find the tighter and looser ones, then setting up a dial indicator to quantify what the various feels actually read at. Take a couple of keys off the frame, and that allows you to hold a dial indicator against a key front side.  Going back and comparing various "feels" on different measured keys, there are some at about .012", which feels firm but clearly has acceptable clearance. The ones I don't like are at about .020-.025.  We are soaking these .020-.025 ones with profelt and letting them sit wit .147 cauls instead of the ,150 cauls we normally use on the front mortice, to see if that tightens them up a tad.

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



  • 6.  RE: new front keybushing clearances

    Registered Piano Technician
    Posted 27 days ago
    Have figured out where in your install procedure the sloppiness crept in?

    BTW 1/64" = about .015" typically SS target standard I think.
    Edit: This is at the FR.  You want only .001" - 002" at the BR

    Pwg

    ------------------------------
    Peter Grey
    Stratham NH
    603-686-2395
    pianodoctor57@gmail.com
    ------------------------------



  • 7.  RE: new front keybushing clearances

    Registered Piano Technician
    Posted 27 days ago
    I always over bush the mortices and iron size the felt after installation. This densifies and smooths the felt so you can have zero play at the BR and almost none at the FR. I also install teflon heat shrink tubing to the FR. This eliminates side pressure bushing grab and last much longer. The felt actually wears the tubing away so when the keys start to get worn, install new sleeves and leave the felt alone.

    The teflon sleeve FR means I usually only replace the felt in the BR and have to iron/ease the original FR bushings if they are only "normally" loose.

    I have found that heat sizing of all bushing is the best way to densify the felt to where proper freedom without wobble is possible. In both action centers and key bushings.

    Of course if your actions are low inertia with high UW, you will find they tolerate friction that would kill a "normal" action. The axiom is Light and Tight!

    ------------------------------
    Edward McMorrow
    Edmonds WA
    425-299-3431
    ------------------------------



  • 8.  RE: new front keybushing clearances

    Registered Piano Technician
    Posted 27 days ago
    I have used Profelt in the past and had great results but don’t have accurate data on how long it lasts? Is it just a temporary remedy or long term?

    Jeannie Grassi
    PTG Registered Piano Technician
    206-842-3721
    grassipianos@gmail.com




  • 9.  RE: new front keybushing clearances

    Member
    Posted 27 days ago
    We had no overnight increase in bushing size with larger cauls, so we pulled one side of the offending keys, and are rebushing that one side with thicker cloth.

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



  • 10.  RE: new front keybushing clearances

    Registered Piano Technician
    Posted 27 days ago
    That is precisely what you must do if you don't catch the issue (too loose fitting caul) in the installation process.

    Pwg

    ------------------------------
    Peter Grey
    Stratham NH
    603-686-2395
    pianodoctor57@gmail.com
    ------------------------------



  • 11.  RE: new front keybushing clearances

    Registered Piano Technician
    Posted 26 days ago
    So, two pianos isn't  a test, but I used profelt on 2 Steinway B's. One was two years ago in a dance studio. That piano gets hard use and only a few keys are loose-ish.

    In both cases I did not use cauls, but let them dry on the key pins. The first time because I didn't have any. The second time, this past spring, I borrowed some, but with the cauls the keys did not improve, so I did it again on the key pins.

    In both pianos they were just loose enough to be noticeable, not loose enough for rebushing. In both cases only very minimal easing was needed and only on a few keys. The pianos were just getting a regulation/voicing once over.

    ------------------------------
    Cindy Strehlow, RPT
    Urbana, IL
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  • 12.  RE: new front keybushing clearances

    Registered Piano Technician
    Posted 26 days ago
    p.s. I have been told not to do that, but was not told the reason. It was someone I would not contradict, so I didn't ask.

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



  • 13.  RE: new front keybushing clearances

    Member
    Posted 26 days ago
    Contradict away...the attribute of big mouths, who impose their unasked mentorship and dominance on groups like this, is that they can convince many folks that they know, by shear force of personality. Listen to them, without questioning, and not only will they slow you down significantly, but make the whole exercise more stressful than it needs to be.

    Instead, my approach is that...there are no mistakes...period.  Experiment and see. Empirical experience is the most reliable and friendly mentor, and removes emotion and social position, two useless quantities in this situation, from what should be a much simpler non-emotional undertaking.

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



  • 14.  RE: new front keybushing clearances

    Posted 26 days ago
    It's a mistake if what you do cannot be corrected without major expense or you don't get the chance to correct it.
    It's not a mistake if you can correct it before anybody else finds out about it.

    That being said,, experiment on your own pianos first. Experimenting on other peoples pianos can have negative results and the techs can't back you up when the owner sues.

    If you have made your final mistake in life that means people are looking to bury the remains.

    ------------------------------
    Keith Roberts
    owner
    Hathaway Pines CA
    209-770-4312
    ------------------------------



  • 15.  RE: new front keybushing clearances

    Member
    Posted 25 days ago
    I don't particularly agree with your understanding of "mistakes", as you define mistake on the negative...but that's fine...to each his own.

    <"...Experiment on your own pianos first. Experimenting on other peoples pianos can have negative results".

    I will however disagree in the strongest terms with this statement as it is commonly voiced, absolutely false, and scares folks away from serious rebuild work

    This statement assumes an experiment piano is a one off thing. It assumes the experiment piano is a one off practice event that confers competency at its completion. To a huge degree, even after practicing on an experiment piano, you will still have huge gaping holes in your skills, processes and results, that will take years to improve, sometimes. Each and every piano will still, if you are challenging your skill set, paying attention to results, and improving the result every time, continue to be a project full of experiments, and thus intentional and unintentional mistakes. The piano is simply too complex to think you will have it mastered after an introductory rebuild or action job, and then you are ready to go. Each new job will have its leap of faith component, well into one's thirtieth year in the business and beyond. Some will be more experimental than others, and some wildly experimental, on purpose, but experiment and informed guesses are the essence of what we do.

    Said another way, there is no certainty.  If one has no capacity for uncertainty, and cannot non-judgmentally accept "mistakes" or lack of knowledge as essential to the work at hand, then the result will be beginner work, over and over again, with no improvement.

    In piano work, and in all artisan work all mistakes are correctable, and not to be feared. Some take longer than others to correct, but there is no fatal error. Serious rebuilders know, that with rework and commitment, the result will always be much better than the vast majority of pianos out there. The results, with serious thought and rework, will be  to "pretty damn good", assuming a high level of commitment to the process...and pretty damn good is pretty damn good.

    Sorry to go on about this, but the bullshit about not doing anything until you have perfected your art is endemic. Its false, and just cuts folks short of doing what they know full well, they are capable of doing, without some big mouth cutting them down.



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



  • 16.  RE: new front keybushing clearances

    Registered Piano Technician
    Posted 25 days ago
    I appreciate and endorse the sentiments you have expressed about experimentation. Now that I have reached a certain age, the way I put it is "I've only been working on pianos for 60 years so I'm still learning".  (I'm not that old... I got my start doing bridle straps for my tuner dad when I was in elementary school.)  But I am still learning and experimenting. As someone once told me, the difference between the beginner and the expert is not that the beginner makes mistakes and the expert doesn't.  Rather, the expert knows how to fix the mistakes. 

    If we don't experiment on customers' pianos, where will we learn? I doubt most of us have the resources to dedicate a certain level of inventory to experimentation -- that's even difficult for piano manufacturers. 

    What I try to get across to the people I am mentoring is the importance of understanding the concepts and principles behind a procedure -- rather than just blindly following some recipe that has been handed down from ages past, even if the origin is from a highly respected individual. That was the thought in my article series about regulation titled "Beyond the Recipe". 
     These are examples of worthwhile questions for someone wanting to understand rather than duplicate rote procedures:
    • What was the design objective?
    • What competing parameters are at play?
    • Was the company (gasp) trying to save money here?
    • What limitations (or advantages) did the company enjoy in the era of manufacture compared to materials, labor, tooling, design resources and physical plant available today? 
    Every piano we service is an opportunity to learn. However, I'm afraid many technicians don't ask those kinds of questions but instead just move their tuning lever from pin to pin and try to make the beats go away. 

    One caution I would make is that some experimentation is only appropriate once one has grasped the basic principles. It is good for a beginner (less than 1000 tunings, for example) to just do as they have been told while they gain preliminary experience in the real world. 


    Keith Akins, RPT
    Piano Technologist
    715/775-0022 Mon-Sat 9a-9p
    Find me on LinkedIn





  • 17.  RE: new front keybushing clearances

    Member
    Posted 25 days ago
    I experiment on customers' pianos all the time.
    But, as an older dog, I've learned to be very careful and to think about the situation.

    I've replaced hammers and damper felts on a square grand; I had asked an expert on square grands for help but he refused. Luckily another well-known tech assisted me via email when I had questions about anything, and I was happy to pay for his help (I was the one to suggest payment.)
    The job came out beautifully, with the only "oh crap" moment being when I replaced the action and all the hammers were off by a certain amount, not close enough to be adjusted individually (I'd replaced a few hammers in different sections beforehand and tested; I thought I was on.) I solved this by simply plugging and re-drilling a screw hole about 1/8" to rotate the action.
    I learned a heck of a lot and it was a real joy to work on that thing.
    Customers were very happy.  My payment was far below the time and energy I put in.
    That's how one learns.

    Yes, I've made mistakes and have regrets about some of my work. None of us is perfect and we ALL make mistakes. I always ask myself: if I screw up, can I reverse this? I'm not going to charge for my screw ups; I once spent seven hours with a customer and charged nothing (long story, and this person is still a customer.) Price of learning.

    My 2 cents.

    ------------------------------
    Don Dalton
    Chester VT
    ------------------------------



  • 18.  RE: new front keybushing clearances

    Registered Piano Technician
    Posted 25 days ago
    Jim,

    That was a beautiful post.  Thanks.

    I suspect Ron N. is nodding in agreement.

    David

    David Weiss
    Registered Piano Technician
    (434) 823-9733






  • 19.  RE: new front keybushing clearances

    Registered Piano Technician
    Posted 25 days ago
    To quote David Andersen- Failure is a gift!

    ------------------------------
    David Brown
    Garland TX
    tunermandb88.com
    ------------------------------



  • 20.  RE: new front keybushing clearances

    Posted 25 days ago
    I am saying to err on the side of caution.
    Quote-
    the attribute of big mouths, who impose their unasked mentorship and dominance on groups like this, is that they can convince many folks that they know, by shear force of personality.

    It appears to me that you, Jim, are one of those people you talk about that rams their opinion over everything as if it's the best and only way, I don't disagree with ego. It's necessary to teach. I appreciate that you test and observe very carefully before implementing and that reduces mistakes.

    Another tech in town told me he screwed up a really expensive piano and it cost him his savings account,,,, Ooops.





  • 21.  RE: new front keybushing clearances

    Registered Piano Technician
    Posted 25 days ago
    Thanks for submitting this Jim. It really goes to the heart of getting courage to try new things, and thereby expanding one’s experience. In any aspect of our lives.
    Cheers,

    Joe Wiencek




  • 22.  RE: new front keybushing clearances

    Registered Piano Technician
    Posted 24 days ago
    I was expecting to hear something about whether or not you should use Profelt in the way I did--drying the bushings directly on the pins.

    Anyone?

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



  • 23.  RE: new front keybushing clearances

    Member
    Posted 24 days ago
    But that was the point of the posts about experimentation. When you experiment in a way in which there is no previous or known testing, since you made the empirical test, you become the only person capable of saying whether it worked or not. There is no imprimatur in this situation, and you have to fly entirely under your own power.

    I have tried resizing to tighten up things with a smaller caul, and it did not work...but that's different than what you did. I can see your test might have worked, at least in the short term, as it may have fluffed the felt up around the pin circumference somewhat, instead of uniformly increased felt size in the entire plane of the bushing. But still, that's a guess...you are the one who has access to the results.

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



  • 24.  RE: new front keybushing clearances

    Registered Piano Technician
    Posted 24 days ago
    Lucinda,

    I have done this numerous times. You did fine. I generally like to let them dry out of the piano when I do this. The goal is to just swell the cloth a bit and restore it closer to where it once was.

    NOT MUCH Profelt is needed. Basically 1-3 drops right at the place of business. That's all. Don't soak it. (DAMHIK).

    You can relax...you did fine.

    Pwg

    ------------------------------
    Peter Grey
    Stratham NH
    603-686-2395
    pianodoctor57@gmail.com
    ------------------------------



  • 25.  RE: new front keybushing clearances

    Registered Piano Technician
    Posted 23 days ago
    I am not so worried about how I did as wondering what my colleague had against the method.

    I have so few opportunities to do that kind of work, that you could not call what I did experimenting. Those 2 times were the only times I had any reason to have the stack off of a nice piano I was trying to improve, in many, many years. Not that many nice pianos in my stable, fewer of them get 'improved.' That's another story, of course.

    I have colleagues that I am too eager to contradict as well as the opposite, just so you get the whole picture!

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



  • 26.  RE: new front keybushing clearances

    Registered Piano Technician
    Posted 23 days ago
    While I don't doubt that its possible to use Profelt on key bushings without cauls, and have a good result, I am inclined to use cauls whenever possible. We've all certainly seen keys on "lesser quality instruments" where the bushing cloth has developed a crescent shape to the extent of wrapping around the key pins. In that case, the key pin has been the caul against which the expanding felt bushing has shaped itself around. As the key moves the friction goes from low to high. I'd rather have the bushing thickness uniform.

    ------------------------------
    Patrick Draine
    Billerica MA
    978-663-9690
    ------------------------------



  • 27.  RE: new front keybushing clearances

    Member
    Posted 23 days ago
    I think Pat's description is the likeliest explanation of why the no caul technique "worked" .

    Hypothesizing about your colleague's thinking on this...The answer is relative, and has to be relative as there are many different viable points of view to consider.

    When we have these discussions, we need to be aware that the assumptions we all bring to the discussions are particular to our personalities and situation. For instance, your colleague may well have the assumption that good work is complete and long term shop work, because, like me, he's a shop rat. According to that assumption, indeed your fix would come up sort. But there are other acceptable assumptions to consider. For example, your situation, where for whatever reason the action is not going to a shop for refurbishment, the goal is immediate functionality. In this case, what may or may not be a short term fix (we don't know), makes perfect sense.

    So, in wondering what your colleague may have meant, the question really is to determine how their assumptions compare with your assumptions. We always assume others share our assumptions, but that is not often the case.

    This is why I said earlier that mentor's opinions can really slow one down. They can impede ones individual development if the mentor's opinions are presented as  "this is how it is done, grasshopper, don't question me", rather than "this is how I approach this problem, for this reason".  Giving the reason communicates the assumption. Knowing the assumption makes it clear whether the advise applies to our situation or not.

    Said another way, the intended communication can be seriously mis-communicated, and we need to be vigilant on this point.
    ------------------------------
    Jim Ialeggio
    grandpianosolutions.com
    Shirley, MA
    978 425-9026
    ------------------------------



  • 28.  RE: new front keybushing clearances

    Registered Piano Technician
    Posted 22 days ago
    Lucinda,
    I have used Profelt with great success but only using the correct size cauls. If dried on the key pins, the felt will expand around them leaving an indented area which could impede the motion of the key.

    Jeannie Grassi
    PTG Registered Piano Technician
    206-842-3721
    grassipianos@gmail.com




  • 29.  RE: new front keybushing clearances

    Member
    Posted 20 days ago
    As a followup to the original post, we figured out what the bushing fit inconsistency was.  My son Dave does the keywork. He was having trouble with the damn hot hide glue, who's consistency can be a real pain in ass, and change throughout the bushing application. Bushings were saturated. He knows how to mix the stuff, and so do I, but consistency on hot hide is just a pain, not to mention, I often manage to leave the pot on when done, making a dangerous mess. So we ditched it. No manufacturer uses the stuff for bushings anymore, anyway.

    So he took half a day to problem solve the application process. We took a piece of pine, cut about 30 key mortises in it, and did a whole series of tests using other glues. We settled on titebond original. We tested for ease of removal...with heat and a little water. Not only does the bushing come out as well as hot hide, but there is none of hot hide's gummy residues. We did test Roo GLue and cold hide, but I didn't like the roo glue residue when removing the bushing, and cold hide takes forever to grab.

    Also gave Bushmaster a second look. By applying glue only to the mortise, the bushmaster razor never touches glue, so it worked a treat, and the razor did not hang up because of glue glop. In the past, trying to apply hot glue to the bushing AKA the spurlock technique, the bushmaster razor gets gummed up by the glue on the back of the bushing. So, Dave  pulled all the bushings, and rebushed with titebond and thicker cloth, and really flew. Not having to fight with glue on the Bushmaster gumming its operation up, really made the tool a breeze to use.

    In this application technique, one difference is, that the same .226" mortise we always use, requires a thicker cloth to get the fit we want. Results were consistent.

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



  • 30.  RE: new front keybushing clearances

    Registered Piano Technician
    Posted 20 days ago
    👍👍

    Pwg

    ------------------------------
    Peter Grey
    Stratham NH
    603-686-2395
    pianodoctor57@gmail.com
    ------------------------------



  • 31.  RE: new front keybushing clearances

    Member
    Posted 20 days ago
    I was just looking for a post from Peter, where he discusses the Bushmaster which he invented. Or at least that's what I remember the post said, but I can't find it in this thread...did I dream that post?

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



  • 32.  RE: new front keybushing clearances

    Registered Piano Technician
    Posted 20 days ago
    Jim,

    You did not dream it. I said it. Sounds to me like you have it under control.

    Pwg

    ------------------------------
    Peter Grey
    Stratham NH
    603-686-2395
    pianodoctor57@gmail.com
    ------------------------------