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Experiences with carbon fiber parts

  • 1.  Experiences with carbon fiber parts

    Registered Piano Technician
    Posted 10-06-2012 04:41

    List
    I'm doing a technical for our chapter on "What's New in the Industry".  One of the things to be discussed is the introduction of carbon fiber uses in the piano industry.  In intend to cover carbon fiber action parts ( from Kawai and Wessel, Nickel, and Gross), carbon fiber tuning levers, and the new carbon fiber soundboards from Steingraeber. Since many of these applications are relatively new I have  limited amounts of information as to how these products will hold up with time.  
    I'm curious as to your experiences with (specifically) the Wessel, Nickel, and Gross parts sold through Mason & Hamlin. I've yet to install any actions with these parts but would love to hear your experiences with the pros and cons from a rebuilders point of view. 
    Do you find them to be better, equal, or less than the traditional wood parts?
    Is traveling of the parts dramatically reduced due to their uniformity?
    Is there a marked difference in tonal power?
    Any unusual issues with the parts behaving over time?
    Have any of you had experiences with the Steingraeber " Phoenix" soundboards? I don't have any clients with this brand but understand the tonal qualities are quite impressive.
    Thanks as always 
    Tom Servinsky

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  • 2.  RE:Experiences with carbon fiber parts

    Posted 10-13-2012 15:54
    Hello Tom

    I do not know if you have had any private response and I see that there has been no response here on pianotech to your request. Unfortunately I am not able to help you out either on this topic. 

    However, may I request of you, that if you do get any valuable, solid and informative feedback on the carbon fibre parts request of yours, would you be so kind and post a report back here on pianotech as to your findings after you have done your technical?

    All the best with your technical!

    Thank you,

    Regards,

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    Mark Davis
    Howick
    0333304184
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  • 3.  RE:Experiences with carbon fiber parts

    Posted 10-13-2012 16:51

    Ok, I'll post my experience with the WNG parts.


    Pros:


    Lots more options than Renner for lever heel placement etc, making action design easier.

    Very uniform and consistent.

    Action has a very smooth, controlled feel.

    Makes for a very nice pianodisc player piano due to the smoothness and consistency.

    Much easier to cast the shanks, (which is lucky if the glue sets before you have a chance to get it right!).


    Which leads me to ...


    Cons:


    Super glue for heads sets up WAY to quick for me.(Lots of coffee and deep breaths required before starting the job).

    Fumes from the glue,(no deep breaths at this stage).


    Clicks!-This is the main one for me..The actions always seem to develop clicks after a while from either the centres, a gap between the shank and flange part, or loose heads.I've never had one not click for one of these reasons.


    Dark to work on, harder to see what your doing whilst regulating.

    I find setting the jack height in the window slightly more difficult than traditional wooden parts.


    My overall impression is: Impressed, but lose the clicks



  • 4.  RE:Experiences with carbon fiber parts

    Registered Piano Technician
    Posted 10-14-2012 06:15
    I did receive some feedback and most were centered around the glue issue being too quick of a set-up time. I didn't get any feedback regarding the clicks however I do remember that was mentioned on this list sometime ago. Sounds like they are still in the perfecting stage.
    Have you installed the parts with the traditional felt center pin bushings or the type resembling that of a teflon bushing.
    I've already did my presentation on the introduction of carbon fiber into our industry. Now I need to get a set of these installed and see for myself the pros and cons. In theory, I like the concept for uniformity.
    Mason and Hamlin has a wonderful high speed video showing the comparison of a good wood shank vs a bad wood shank vs a carbon fiber shank during a hard blow. If you haven't seen the video, it's a worth the look. 

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    Tom Servinsky

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  • 5.  RE:Experiences with carbon fiber parts

    Registered Piano Technician
    Posted 10-15-2012 07:52
    A few years ago when WNG parts had felt bushings, before the new bushing material, we installed a set. There has been some problem (actually a lot) with sticky action centers...thankfully the customer is around the block from my shop. I guess that's why they changed to the "hard bushing material". I have yet to try the parts with the "hard bushing material". I've seen the parts and played them at NAMM ... They feel amazing.. Direct response and very little energy needed to play. ------------------------------------------- David Estey, RPT www.EsteyPiano.com Piano Tuners Sales Tips for the week. FREE! Sign up here: http://coolstuffformusicians.com/fine-tuning-your-salesmanship Creating Harmony in a World filled with Discord. 1-800-ON A PIANO (662-7426) dave@esteypiano.com -------------------------------------------


  • 6.  RE:Experiences with carbon fiber parts

    Registered Piano Technician
    Posted 10-16-2012 02:36
    I have installed a couple complete actions with WNG parts. The first action was with wool bushings. These parts had many issues - repinning of the parts was difficult because the bushings often would get pushed out along with the pins. I came very close to sending them back and it took a couple years before I overcame my gun shy state of mind regarding these parts. Rebushing was next to impossible for me as the glue would not adhere. The parts required lots of aligning, heating, bending, travelling. I was not pleased, yet the action is working now and has been trouble free. When it comes time to repin, I will probably replace parts with the newer hard bushing parts. I did use the white glue that WNG supplied at the time for gluing hammers to shanks. I have had no issues to date with clicking or loosening of hammers from shanks.

    The second action was a complete top stack replacement on a Young Chang with expanding brackets. This was done last spring with hard bushings. The pinning of parts was much better. Very little travelling required, and they were consistently within spec for the parts (2-3g for hammers, 5g for rep levers). I used the CA glue for the hammers and I liked the process much better than I thought I would. Jury is still out on how well the hammer to shank joint lasts. The hard bushings are tricky to work with. If you push out one of these, you will have difficulty getting the pinning where you want it. But there are some tricks you will learn as you do it. You must use the pin keeper tool that they supply with their pinning kit. It works only on hammer flanges. They are in the process of designing one for rep lever pins too as I understand it, and I assume also for wip flanges. I hope so, because they are absolutely necessary for successful pinning. I really like the backchecks, key pins, capstans, perimeter bolts. I plan on using these parts for most if not all of my jobs.

    I did attend one of their week-long classes and that turned out to be a great investment. Bruce Clark and the others at the M&H factory did an outstanding job. No I'm not getting a kick back. :-)   But I am enthusiastic about the parts.

    I echo Ron N's well-expressed thoughts about WNG parts design. The ability to easily change heel size and location are a fantastic option when you need to change capstan location. 
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    Alan McCoy
    Spokane WA
    ahm2352@gmail.com
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  • 7.  Experiences with carbon fiber parts

    Posted 10-14-2012 09:53
    On 10/14/2012 5:14 AM, Thomas Servinsky wrote: > > > I did receive some feedback and most were centered around the glue > issue being too quick of a set-up time. I didn't get any feedback > regarding the clicks however I do remember that was mentioned on this > list sometime ago. Sounds like they are still in the perfecting > stage. Have you installed the parts with the traditional felt center > pin bushings or the type resembling that of a teflon bushing. I've > already did my presentation on the introduction of carbon fiber into > our industry. Now I need to get a set of these installed and see for > myself the pros and cons. In theory, I like the concept for > uniformity. Mason and Hamlin has a wonderful high speed video showing > the comparison of a good wood shank vs a bad wood shank vs a carbon > fiber shank during a hard blow. If you haven't seen the video, it's a > worth the look. I've had so little action work the last three years, that I haven't gotten nearly as much experience with these parts as I'd like, but I do have some observations. First, I like the concept of uniform engineered materials with designed, rather than resulting weight distribution, and non reactivity to humidity changes. I very much like the versatility of the parts combinations in accommodating a wide range of actions. This is a real luxury. Handling the parts, I was concerned about the side to side flexibility of the wippens as compared to wood, but that doesn't seem to be a problem in use. While the parts are overall as heavy or heavier than wooden equivalents, the weight distribution is better, and they weigh off lighter than wooden parts in use. In my limited experience center pinning, both with the original wool and now with the hard composite bushings, is less uniform than it ought to be, but that is apparently an eternal and near universal problem in piano parts manufacture. The clicks mentioned by others are associated with my two greatest concerns about these parts. One is the bushings. Again, I lack more than superficial familiarity with these hard bushings, but reports from other techs would seem to indicate still unresolved problems. This may well improve with time. My biggest concern is the one I had immediately with the use of carbon fiber shanks, most especially when the glue for hanging hammers was Assembly 65. I insisted that gluing a humidity reactive wooden hammer molding to a non hygroscopic carbon fiber shank with a wood glue was doomed to fail in the long run no matter how many test blows the system was subjected to in the short term. Eventually, and soon in extreme climates, that joint was going to fail. Turns out it did, so they switched to CA. CA has a better chance than Assembly 65, but it's still gluing a hygroscopically reactive molding to a non reactive shank with a rigid glue, which still isn't on my list of dependable gluing techniques. I like the idea of the uniformity of the carbon shanks just fine, but I don't like the gluing method one bit. Maybe they need a good Nitrile adhesive that sticks well to both wood and epoxy and moves with the wood without cracking loose from the shank. I got a chance to install a back action earlier this year, and I like the design. I would like to see the hole in the top block for the wire to be deeper, however. I'm also interested to see how the pressure sensitive adhesive holding the cloth strip to the tray ages. I don't use PSA on long term assemblies of any sort because of longevity issues, so I'm interested to see how this stuff fares. Very nice parts overall, well designed and executed, with a couple of remaining warts. Ron N


  • 8.  RE:Experiences with carbon fiber parts

    Registered Piano Technician
    Posted 10-15-2012 05:50
    These past few weeks became a huge learning curve for as I started to research the structural benefits of carbon fiber parts. Not to mention the uniformity improvement. If you haven't seen the high speed video on the flexing of shanks, this is worth a look. It compares a good wooden shank (which is still considered the premium set-up) to a bad wooden shank. The point is that in any set of shanks, there will be some bad shanks sprinkled in. The carbon fiber shanks perform very much like the premium wooden shank, only with a much higher level of uniformity.  Take a look at the website and scroll down to the video.
    http://masonhamlin.com/wessell-nickel-gross
    The hardened bushing issue is going to be the issue I'll continue to have with these parts. I would prefer the traditional felt set up that has been proven to hold up over time.
    Tom Servinsky

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    Tom Servinsky

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  • 9.  RE:Experiences with carbon fiber parts

    Registered Piano Technician
    Posted 10-14-2012 23:04
      |   view attached
    Tom, 

    I've installed two top actions from WNG, and attended their week-long class at the Haverhill factory.  My first experience was with an early incarnation of the composite parts with hard bushings (which came just after the wool bushings).  We also did one very recent set this summer.  I like the results of both, but there was a learning curve.

    The hard bushings promise to last a very long time.  I had the good fortune to be at the factory training class in Haverhill when test shanks arrived, having been subjected to millions of blows on a player grand.  Wood and wool parts were played for weeks along side composite and hard bushings.  The wool bushings were completely destroyed.  There was very little bushing cloth left in the holes.  The striking surface of the hammers were worn flat from flailing around.  In sharp contrast, the hard bushings showed very little wear.  The striking surface of the hammers had crisp string cuts.  I'm sure there was a little slop, and the friction had decreased to zero, but the bushings were still functioning long after the traditional wool had been worn down to the wood.  

    But... Hard bushings are a bit of a pain to pin up or down to friction targets.  The tools and pins are not compatible with our old wool bushing tools.  The center pins vary by 0.0001, not 0.001.  The centers are expanded by pressing in "reamers" which compress the plastic, rather than cut it.  Getting the pinning just right and keeping it there is still a bit of an art.  There is also risk involved.  If you push too hard on the reamer, the plastic bushing may pop out of the flange or shank.  They are only a press fit, not glued or fused.  Once you pop them out, you can't pop them back in, because the likelihood of aligning the hole concentric with the other bushing is slim.  You essentially have to toss the part.  If you are in the field, you could rebush both bushings with cloth as an emergency fix.  In the shop, we order replacement parts.  The good news is that they come from the factory in pretty good shape, so pinning is limited to a few bushings here and there.  

    One thing I noticed when measuring bushing friction:  The first move of a bushing seems to have a higher "breakaway" static friction than the second movement.  I don't know if that goes away after the action is broken in, or if it is noticeable to the player.  It is something I have been meaning to check on our older installation.  

    Regarding travelling, the first set I did seemed to be very consistent.  I needed to travel 60 out of 88 shanks to the right.  Just a little.  The more recent set, which we ordered installed on a custom top action stack, was already traveled for us, didn't appear to have much paper, and I had very little touchup to do.  

    The flexibility of variable height and location of wippen heels and knuckles allows very precise action ratio design.  The variety of available flanges is wonderful.  The ease of "burning" shanks to vertically align hammers is a joy.  

    I don't think I've heard enough of these actions yet to know exactly how they impact piano tone.  I've been meaning to replace a few wooden shanks with composite here and there, using the same hammers (which need to be plugged and rebored to fit the smaller carbon shanks), just to do a side by side comparison.  I've heard people describe the sound as "crisp", "fast blooming", and "almost electric".  To me, they sound like pianos.  Good pianos.  Pianos with clean, firm bushings and stiff shanks.  They don't sound like something from Mars.  

    Certainly, there are hundreds of these actions now in service in new Mason and Hamlin pianos, so tone and mechanical reliability data is being produced daily.  

    I really like the composite parts when they are part of the whole WNG system.  The custom scale-stick boring of action rails, and assembly of parts, ready-to-install is a bargain.  I would not hesitate to use their top actions again.  In fact, I have a few proposals out with customers to do just that.  If a piano has action rails of an obsolete design, or the original action geometry is way off, WNG is the way to go, hands down, based on cost and predictability of outcome.  The cost/benefit becomes less clear if the original geometry is ok and the stack frame is in good shape.  Wood wips and shanks are still competitive for "normal" size parts.  I don't think I would use a new WNG top action for Steinways.  Even if the original stack frame is shot, new frames are available from the Steinway factory for a reasonable price, and you can screw on genuine SS or clone parts and get good "authentic" results.  Even though I think results are more important than authenticity, the resale value is a concern to many SS owners, and excellent results are still possible with genuine parts.  All other pianos are potential WNG installs.  Especially the really weird ones.  Did I mention my second installation was a Kranich and Bach?  

    Photo attached shows the underside of a WNG top action while gluing wip heels in place.  I ordered the heels "loose", and in several sizes, so we could optimize the geometry.  Note the WNG capstan mounted on a maple block on the key.  By relocating the capstan, there is almost unlimited control over action ratio using WNG parts.  Also visible are the new maple cleats on the keyframe, cut to place the top action at the correct height.  I hung the hammers, rebushed the keys, and installed new backchecks.  Result: A factory-new action. 
     
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    Greg Graham, RPT
    Brodheadsville, PA
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  • 10.  Experiences with carbon fiber parts

    Posted 10-15-2012 08:03
    On 10/15/2012 4:50 AM, Thomas Servinsky wrote: > > >If you haven't seen the high > speed video on the flexing of shanks, this is worth a look. It > compares a good wooden shank (which is still considered the premium > set-up) to a bad wooden shank. The point is that in any set of > shanks, there will be some bad shanks sprinkled in. The carbon fiber > shanks perform very much like the premium wooden shank, only with a > much higher level of uniformity. Yes, I've seen the video, and have no problem with the carbon shanks being more uniform than wood. I don't see how that couldn't be a good thing. My point and problem is with the concept of gluing a hygroscopically reactive molding to a non reactive and non porous shank with a rigid glue. As the molding continually changes dimension the glue will eventually separate from the shank. I was originally assured it worked just fine with Assembly 65. It didn't, and there was no way it ever could have. I'm now assured it works just fine with CA, but I don't see how it could in the long run any more than it did with Assembly 65 for the same reason. I suppose we'll see, but wonderfully uniform shanks that the hammers drop off of doesn't strike me as a net gain over wood shanks. The bushings, I haven't seen enough of to really have an opinion. I am curious what the material is and how it's held in the flange, and I haven't tried repinning them though the back action I installed could have used some repinning. If they wear well and stay tight in the long term, they have the potential of being less prone to degrading tone than wool bushings. Again, we'll see. Come to think of it, I don't recall any discussion on repinning these parts, and someone surely has. Does anyone out there have methods, tips, tricks, and gotchas they'd care to pass on for the general enlightenment and terror enhancement of the rest of us? Ron N


  • 11.  RE:Experiences with carbon fiber parts

    Registered Piano Technician
    Posted 10-15-2012 08:28
    So, should hammer moldings be made of something other than wood?

    Or might wood moldings be treated in some way to increase the length of the bond, by say, soaking the area around the bore with some agent to decrease its porosity?

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    Kent Swafford
    Lenexa KS
    913-631-8227
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  • 12.  Experiences with carbon fiber parts

    Posted 10-15-2012 08:28
    On 10/15/2012 6:52 AM, David Estey wrote: > > > A few years ago when WNG parts had felt bushings, before the new > bushing material, we installed a set. There has been some problem > (actually a lot) with sticky action centers...thankfully the customer > is around the block from my shop. I guess that's why they changed to > the "hard bushing material". I have yet to try the parts with the > "hard bushing material". We discussed this once on the list a bunch of years ago, but it mostly doesn't come up. In cloth bushed wood, as the humidity increases, the cloth expands and tightens on the pin. At the same time, the hole the bushing is in expands, and loosens the cloth's fit on the pin. So it's to some degree self correcting. Given a flange that doesn't change dimension with humidity swings, the hole remains the same size and the fit of the pinning in the cloth should change more with humidity changes than wood flanges, getting tighter in wet weather, and looser in dry. We were going to do a set of simple experiments to verify all this for a Journal article, but it never happened. Steinway had the opposite problem with the Teflon bushings. The flanges reacted to humidity and the bushings didn't, so the pinning got tighter in dry weather and looser in wet. Kindergarten materials science is a fun thing. Ron N


  • 13.  Experiences with carbon fiber parts

    Posted 10-15-2012 09:03
    On 10/15/2012 7:28 AM, Kent Swafford wrote: > > > So, should hammer moldings be made of something other than wood? > > Or might wood moldings be treated in some way to increase the length > of the bond, by say, soaking the area around the bore with some agent > to decrease its porosity? I'd try a more appropriate glue first, before getting into extra prep steps or different molding materials. 3M makes a Nitrile adhesive (Scotch-Weld) that will bond well to the shanks, and ought to be flexible enough to accommodate the seasonal movement of the molding without separating from the shank. A quick experiment on a few samples would demonstrate if, and how tone is affected (which might be a deal breaker - or not), but I'd have considerably more faith that the hammers would still be on the shanks in five years than I currently have with the CA approach, especially after the Assembly 65 experience. Ron N


  • 14.  Experiences with carbon fiber parts

    Registered Piano Technician
    Posted 10-15-2012 09:48
    This may be a dumb thought but won't the hammer molding eventually suffer from a similar problem to the Teflon bushings? If the wood tightens up around the immobile shank, crushing some of the fibers, and then shrinks it will never quite get back to its original dimension. Unless the glue can absorb these changes like caulking does, wont it eventually break loose or at least make noise? Sorry if I'm seeing this wrong... ---Dave New Orleans On Oct 15, 2012, at 8:03 AM, Ronald Nossaman wrote: > > On 10/15/2012 7:28 AM, Kent Swafford wrote: >> >> >> So, should hammer moldings be made of something other than wood? >> >> Or might wood moldings be treated in some way to increase the length >> of the bond, by say, soaking the area around the bore with some agent >> to decrease its porosity? > > I'd try a more appropriate glue first, before getting into extra prep > steps or different molding materials. 3M makes a Nitrile adhesive > (Scotch-Weld) that will bond well to the shanks, and ought to be > flexible enough to accommodate the seasonal movement of the molding > without separating from the shank.


  • 15.  Experiences with carbon fiber parts

    Posted 10-15-2012 12:48
    On 10/15/2012 8:48 AM, David Doremus wrote: > > This may be a dumb thought but won't the hammer molding eventually > suffer from a similar problem to the Teflon bushings? If the wood > tightens up around the immobile shank, crushing some of the fibers, > and then shrinks it will never quite get back to its original > dimension. Unless the glue can absorb these changes like caulking > does, wont it eventually break loose or at least make noise? Sorry if > I'm seeing this wrong... I don't know that the wood would crush, but the fact that it moves and the shank doesn't will eventually break the joint with a rigid glue - unless there is give in the glue to accommodate it. This is what I've been saying all along. Ron N


  • 16.  RE:Experiences with carbon fiber parts

    Registered Piano Technician
    Posted 10-16-2012 07:46
    Man...I wish all of these responses would have come through in a timely manner, say last week, just before I gave my presentation last Wednesday. Timing is everything. 
    My daughter is an engineering student at Georgia Tech and is working at Delta this semester in the engine department. I'm going to have her pose the gluing issue to their chemical department. Seeing that they use a lot of carbon fiber in their production, their R& D findings should have some suitable benefit for this discussion.

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    Tom Servinsky

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