Evolutionary Piano Project Launching on Indiegogo Soon - Carbon Fiber Soundboard

[regnistep]

I want to make the members of the Piano Forum aware of a crowd-funded project that will launch on Indiegogo in 3-4 weeks. The goal of the project is to build a custom grand piano to serve as a test bed for a ribless carbon fiber composite soundboard. The soundboard will be optimized with evolutionary computing techniques that will build and test 100's or even 1000's of soundboards entirely within a computer, and evolve the perfect soundboard shape, size and material properties according to fitness criteria describing optimum acoustic performance. The design team includes:

Del Fandrich, who will design the scale and provide guidance throughout the project

David Rubenstein, who will help design and build the piano

Chris Osbourne, who will build the custom composite soundboard, and me,

Jeff Petsinger, I am project manager and technical lead overseeing the computer simulation tasks.

The piano will also feature an expanded compass of up to 108 keys (not decided yet), bridge agraffes, a welded steel plate, a steel rim plate, and WNG actions.

Here are some links to a technical presentation on the project on You Tube and the project website:

Evolutionary Piano Technical Presentation
https://www.youtube.com/watch?v=tyEQ6WFTBGw

Evolutionary Piano Website
https://www.evolutionarypiano.com/

We are also on Twitter and Facebook
https://twitter.com/EvolutionPiano

The pitch video will hopefully be ready to launch in 3-4 weeks. At that time, we will be looking for contributors to the project, but more importantly, we hope you will inform other piano enthusiasts about the project. This forum has spent a lot of time discussing the potential merits of a carbon fiber soundboard, and an equal amount of time lamenting the fact that nobody is doing anything about it. Well, this is it! This is the opportunity to help technologically advance the piano in a way no major manufacturer is willing to risk. Please check out the links. I will be here as much as my job and time allow to answer your questions.

Sincerely,

Jeff Petsinger

[visitor]

Fandrich is a name I know well.  Dude is a genius.  Rubenstein pianos are rad. Project sounds awesome ad legit.  Exciting! Good luck!!!

[faulty_damper]

One of my goals in life is to build carbon fiber pianos.  There will be no wood so it will be incredibly light and many mechanisms will be proprietary and will make regulation so easy even the pianist can do.  As for the carbon composite soundboard, I'm glad you're exploring and experimenting with the possibilities of this material.  Don't forget the interaction between the soundboard, the frame, and the rim, as well as the projection from the lid.  All of these parts should also be carbon composite, though the cost will go up exponentially.  Maybe that could be a special edition elite model.

Also, if using CFCM, the anticipated tone should be much larger than a wooden soundboard, so the size of the piano could be reduced and still maintain the dynamics.  9 foot concert pianos are so last two centuries.

Also, floating or partially floating soundboard design should be considered.

[regnistep]

You have a lot of interesting ideas.  One of the main reasons for adopting carbon fiber, aside from eliminating the inevitable cracks, collapses and instability in humidity, is to elimnate the reinforcing ribs on the underside of the soundboard.  Those ribs really hurt the tonal richness of wooden soundboards above 1100 Hz because the mode shapes become confined between the ribs.  That means that right now, there is a lot of acoustic information created by the strings that is just getting lost in the soundboard because it doesn't have enough modes in the treble to reproduce them.  The treble is where I hope to make a big improvement.  The question is, will people accept that new sound as an improvement, or write it off to the carbon fiber coloring the sound.

If the carbon fiber behaves like it has in other instruments, it will be louder, but also more responsive.  The CFC board can be drastically thinner than a wooden soundboard.  With regards to length, I still value long bass strings to lower the inharmonicity and emphasize the fundamental tone.  We are still discussing the pros and cons of adding notes in the bass and treble.  The choice is to add significant length to the piano to get the lowest note to sound good, or use the length to make the lowest note in a traditional 88 key piano sound really good, and let those lower notes that don't get played much suffer.  David Rubenstein addressed that problem by building a 12'-2" piano with an awesome bass.

We are going to use a waterjet cut steel rim mounted to the inner frame to terminate the soundboard into in stead of mounting it directly to a heavy wooden inner rim like all pianos today.  Although it is tempting to use CFC everywhere, there are places in the piano where there is no substitute for mass.  When you look at the equation that defines acoustic impedance, you want a high strength, high mass material to create the biggest impedance mismatch possible with the soundboard so that sound reflects back into the board instead of moving into the rim.  I think it was Steinway that built pianos for awhile with cast iron rims.  Those pianos were reportedly ridiculously powerful, but too heavy and expensive to make and transport.  The steel rim will also provide a durable mounting surface in the event that we have to try several different soundboards to tweak the sound.  I budgeted for 3 rounds of soundboard trials.

I am lucky to have Del on the team as well as David Rubenstein.  The soundboard that Del invented for his upright pianos struck me as both a stroke of genius and a work of art.  He was in effect trying to address the same problem in the treble that this project will hopefully solve.  I have never heard one of Del's uprights, except on YouTube, which isn't helpful.  I know a lot of people think very highly of them.

[silverwoodpianos]

Floating sounding boards have been around for a long time.

https://pianomaker.co.uk/technical/floating_soundboards/

[regnistep]

It just goes to show you there is always something new to learn.  It is hard to get my mind around the effect floating the soundboard would have, but you have given me another variable to play with in the event the computer is unable to reach the design goals with a standard clamped perimeter.

[chrisbutch]

Presumably you'll be aware of the carbon fibre soundboard pianos already being made under the Phoenix brand name by Hurstwood Farm Piano Studios in the UK with Steingraeber?https://hurstwoodfarmpianos.co.uk/phoenixpianosystems.php?page=phoenix&catid=6&id=1
As well as the pianos now in production with cf soundboards, Hurstwood Farm also have on display a prototype instrument made almost entirely of cf.

[regnistep]

Yes I am aware of them, and thank you for giving me the opportunity to differentiate what we are doing from what they did.  From what I understand, their board is cut to shape from a stock sheet of carbon fiber composite.  These stock sheets are typically about 8 layers of all carbon fiber laid out with the fiber oriented at 0,-45,90,-45,0 degrees to create what is called a quasi-isotropic material, meaning it acts as though it is made of one material type with identical material properties in all directions, in all places, across the entire sheet.  It also starts its life as a flat sheet, and is reinforced with ribs as in a wooden piano.  I do not know if the ribs are imparting a crown, but I suspect they are.

The Evolutionary Piano project will begin by using a computer to search for an optimum shape, both in the perimeter, and in cross-section.  So, there is a chance it could come up with a really wild looking design since this type of simulation often produces non-intuitive results.  Part of the reason I chose to build a custom piano is that it gives me the freedom to shape the inner and outer rim the way the computer suggests instead of shaping it to fit in an existing piano frame.  Furthermore, the Evolutionary piano will use carbon fiber and other fiber types to introduce some damping to take away some of the brittle, metallic sound in the treble that some carbon fiber instruments are known for.  And even further yet, the Evolutionary Piano project will optimize the perimeter shape and fiber orientation of each and every layer in the stack up.  This has the effect of changing the material properties, specifically the modulus of elasticity and Poisson's ratio, at every point across the surface of the board, giving the computer ultimate flexibility to find an optimum design.  The board will be manufactured with vacuum infusion over a shaped tool based on what the computer recommends.  Each layer will be laser cut to shape, and precisely located and oriented on the tool.  So, it starts its life as a non-planar, slightly curved surface.  I am only guessing, but I  think it will have a shallow bell shape in the cross-section.

Lastly, The Evolutionary Piano soundboard will not have any reinforcing ribs, which should allow it to provide many more vibrational modes in the treble to reproduce the input from the strings.  Whether or not this is perceived as a good thing remains to be seen.

So that is the difference!

[polishookm]

For all interested in carbon fibre I suggest: Print this thread out and bring it to Hurstwood Farm Pianos. And discuss. Get their side of the story on what's been described so far. Because they've been mentioned in this thread and what's been described in my opinion includes serious inaccuracies and assumptions.

Of course HFP can explain with detail that I can't the technology they use, the design decisions that support it, and the practical experience that follows.

Probably everyone reading this knows carbon fibre has been a large part of Hurstwood Farm Piano stock for a number of years. They've been retrofitting carbon fibre components to existing pianos for a number of years as well. And they have an instrument that's completely carbon fibre. I'm fairly sure it's production-ready. If not then it's on the tip of the cusp of production. I've played that instrument. It's quite a piano.

Richard Dain has published on design and manufacturing issues with carbon fibre. That's a piece of the puzzle. It's primary source material which in any serious discussion is essential.

Of course their carbon fibre pianos are on the floor - a good number of them - and they're there ready to be played. They're fabulously maintained by Geoffrey Sapsford who's an extraordinary technician.  I've played some of their instruments in my own piano search. The "last man standing" for me was the Steingraeber Phoenix 205 I purchased there last summer. So that's my interest in the discussion. I've been there, played their pianos, and asked questions about them. What I'm hearing in this thread definitely doesn't match to what I heard there.
 

[faulty_damper]

Polishookm,
What specific inaccuracies are you referring to?

[polishookm]

"Yes I am aware of them, and thank you for giving me the opportunity to differentiate what we are doing from what they did.  From what I understand, their board is cut to shape from a stock sheet of carbon fiber composite.  These stock sheets are typically about 8 layers of all carbon fiber laid out with the fiber oriented at 0,-45,90,-45,0 degrees to create what is called a quasi-isotropic material, meaning it acts as though it is made of one material type with identical material properties in all directions, in all places, across the entire sheet.  It also starts its life as a flat sheet, and is reinforced with ribs as in a wooden piano.  I do not know if the ribs are imparting a crown, but I suspect they are."
"

HFP boards aren't isotropic. In addition, they use both flat and crowned boards. Ribs are made from either wood or carbon fibre or in some pianos not used at all. Because the variants have advantages, and merits on particular registers.





 

[regnistep]

I just went to their site and every picture I see shows the underside of the carbon fiber board reinforced with wooden ribs.  For you to declare that their boards are not isotropic would imply that you have intimate knowledge of their manufacturing process, either first hand, or through some article that has been written about their pianos.  You can't look at a carbon fiber board and know its internal construction.  If you have some written material to back this up, I would be very interested in reading it.  Lastly, they are retrofitting an existing piano frame with a carbon fiber soundboard.  One of the key differences with the Evolutionary Piano project is that evolutionary computing techniques will be used to "discover" or "evolve" the optimum shape for a piano soundboard, and then build a piano around that new shape.  As with many things, the details matter.

Summary:

1. Phoenix pianos appear to have wooden ribs.  Evolutionary Piano will be ribless to improve the treble.
2. You say their boards are not cut from stock carbon fiber sheet, my sources say they are.  If you produce an article saying otherwise, I will surrender this point.  The Evolutionary Piano will change the perimeter shape, fiber type, and fiber orientation on every layer (8-10 layers) to customize the material properties at every point on the surface of the board, and the board will be formed to a non-planar shape over a contoured tool.
3. The fact that they are retrofitting an existing piano at the very least means they are not searching for an optimum shape, which makes the Evolutionary Piano project new and unique.

I also want to make it clear that I have nothing but admiration for Richard Dain and the Phoenix pianos.  In the course of pointing out differences, it is easy to misinterpret my comments as an attack on their pianos.  It isn't.  I just think there is still more to do.

[dainphnx]

I am bound to reply to the “evolutionary piano” post – reply #7 on: March 30, 2014, 06:03:21 PM.   We would like to correct some facts.

Our  broad and over-riding response is that with Steingraeber, we have already built, patented and exhibited working pianos in Italy, France, Germany the UK and America with carbon fibre sound boards and other carbon fibre parts for the past five years, in particular at NAMM and the Frankfurt Piano Festival.   We have completed building, and publicly exhibited a grand piano made almost entirely out of carbon fibre, which is almost ready to go into production.  If any reader feels he wants to be the owner of one of the first grand pianos made almost entirely out of carbon fibre, we are ready to contract to supply and would be delighted to discuss terms.   

 Anyone who invests in the “evolutionary piano” is going to be a long way behind us.  We generally do not need to be concerned about people who copy us because, by definition, they are technically behind.   If someone wants to buy a more traditional piano with wood case but with a carbon fibre sound board, they are available now from Hurstwood Farm Pianos in the UK, Steingraeber & Sohne in Germany, and Atlantic Music Centre, Fl. for North America, at modest price.  There are five sizes from concert grand to baby grand.  The four smaller sizes are ex-stock but concert instruments are built to order.   

Marketing of these pianos in America is licensed to Atlantic Pianos in Florida who hold some stock; they have exhibited widely in N America.  We are aware that some of the team on the “evolutionary piano” have visited some of these exhibitions and have questioned our staff (and those of Atlantic Pianos) on the design.   The brother of one of the team has bought a Steingraeber -Phoenix piano with our carbon fibre soundboard.  We have also been asked to supply one of our bridge agraffes to them.  We were told it was needed to repair a broken agraffe on a piano.  We asked for return of the failed agraffe and found it had either been deliberately broken or had been grossly abused by screwing down, with the knife edge not properly in position. This is the only Phoenix bridge agraffe that has ever failed out of many thousands now in service on our Phoenix pianos.  The piano had been previously used on exhibition tour so more than one technician had worked on it.


1.   Our carbon fibre board is not 8 layers thick.  Since some of the layers are woven with several different unsymmetrical weave patterns, it is possible that someone trying to deduce their structure might think they had 8 layers.  Some years ago, Fazioli built a piano with robust carbon fibre board and it is reported that they found that a carbon fibre board doesn’t automatically lead to acceptable sound in fortissimo playing. 

2.   The evolutionary team suggest our board is isotropic.  It is, actually, deliberately and strongly an-isotropic.   The optimum orientation and properties of the fibres in each layer are carefully and specifically defined for each application.  Special tooling is required to do the job to the required standard.  The advance technology of making the fibres we use, so far as we know, is not available in America.

3.   Our board is not “cut out from stock material.”   Each board is designed, made and shaped for the particular piano. 

4.   The precise geometry of our board was studied by finite element analysis and several other more complex modal analysis mathematical processes.  In this way, we were able to demonstrate the Eigen (natural) frequencies for several hundred combinations of board/strings /bridge and case (of different geometry and rigidity), in all the frequencies of the piano register.  We also demonstrated the vibration patterns of all the components of a piano, including the soundboard, the sub-frame, the case, the key bed, and the rim.  We compared their related phasing in response to each note in the register of the piano.   The evolutionary piano team imply they are the first to do this kind of analytical work.   We carried out hundreds of this kind of analysis over three years ago.  That work still continues today.  However, we also were not the first to use modal analysis.   We probably did a more extensive analysis than other prior studies that have been published on the internet, before we adopted and extended the technique.  The evolutionary team would do well to study this prior work to be sure they are correct in claiming originality.

5.   We have studied both flat and crowned boards and also those with wood or carbon fibre ribs - as well as those with no ribs at all.  Currently we use these variants in our commercial Phoenix pianos.   Each option has its own advantages, merits and acoustic effect on particular registers.  The claim that:  “elimination of the ribs removes confinement of the vibration cells to between the ribs” is probably an over- simplification.  It is correct to the extent that if no ribs are present the vibration cells do not “lie between ribs” because there is nothing to lie between; but the general nature of the cells in the treble registers and their related phasing is little changed by eliminating ribs.  There are, however, ways of controlling the vibration cell count and shape in this register. 

6.   The two types of agraffe proposed for the evolutionary piano have a close resemblance to those used by Stuart on his pianos.  We have patented the use of our bridge agraffe, which eliminates down bearing on any sound board. This is a contributory factor to the fine sound quality of our pianos with a carbon fibre sound board.  These are designed for those who seek the same sound quality one expects from a traditional piano.   It avoids the metallic sound that the team deduce is a consequence of using carbon fibre sound boards.  We know of this issue and have studied it in depth and overcome the problem.   

7.   Clearly our work has been closely studied because not only does the evolutionary piano with carbon fibre sound board re-invent our wheel but it also adopts a name we tested on our website, for our piano. However we later discontinued its use because feedback from the market showed it to be counter- productive in terms of conveying the right image for marketing. 

8.   The evolutionary team have even followed our lead in using a continuous capo d’astra bar across all the registers with special agraffes at either end of the sounding length of string.  However, in my opinion, they have misunderstood how these work and are best applied.       Continuous capo d’astra bars were used by Steingraeber & Sohne, and probably others, nearly a hundred years ago.

Hurstwood Farm Piano Studios

 https://www.hurstwoodfarmpianos.co.uk/

[regnistep]

For the record, we haven't copied your work since my only knowledge of it is some online articles that were meant for general consumption, and did not go into enough technical detail for me to know any of these things.  I would very much appreciate a link to any technical publications on your work so that I don't make the mistake of arguing when I am uninformed.  But there are a few of your comments that I can address because they don't require knowledge of what you have done.

I am repeating myself, but we are not copying your work because I am unaware of the details of it.  If we are proposing to do the same thing you have done, it is simply a case of knowledgeable people following the same technical path.  I am working with two people that stay more current on developments in the piano world, probably the people who visited you at exhibitions.  Both of them are of the opinion that we are doing something new and unique.

The advanced technology to make composite materials is really not all that advanced, and we have a full range of capabilities and access to the highest performance fibers here in America, not that the finest carbon fiber is required for this job.

I stand corrected regarding the quasi-isotropic properties of your soundboard, but I will need more information on the design process you used to select the fiber orientations, layer shapes, etc.  Again, I would very much like to review your work so I can understand what you have done.

Regarding the bridge agraffes, we have not selected a design for the project yet.  There might be some pictures on our website, but are only there for illustrative purposes.  The same is true of other details on the website.  The design shown is one of the many designs David Rubenstein has generated.  David built the site for me, and dropped in those image as eye candy.  So, don't waste anymore time dissecting them.

I came up with the Evolutionary Piano name based on the computing techniques we plan to use to find the correct shape of the soundboard.  Again, I am tempted to coin the phrase' great minds think alike", but the tone of your post suggests you might not appreciate the humor.  I have noticed that all of the Phoenix pianos have a very traditional shape to them.  I am not expecting the Evolutionary Piano to look that traditional.  The pictures I have available to me show carbon fiber on the underside, but a light colored material on top.  Can you tell me if that is wood on top?

I suspect that there are still differences between what you have done and what we plan to do, but I am not able to argue that point without seeing your published papers, patents, etc..  I am completely sincere when I ask that you point me to where I can look at them.  If I am actually following in your path, I will admit it. 

 

[dainphnx]

The Steingraeber-Phoenix, and Phoenix piano ranges have been established for some time. They incorporate variants of custom designed carbon fibre soundboards including those with a thin wood veneer on the upper surface. Our domestic market mainly prefers to maintain a traditional appearance. Others have been built showing the carbon fibre surface of the board along with other contemporary features.  Hurstwood Farm Pianos have continued to develop their technology since the launch of this range and exhibited the prototype Phoenix CF all carbon fibre piano in 2013 at Cremona Fiera Pianoforte, Italy.  It may be of interest to view photographs of the Phoenix CF in the news item on the Hurstwood Farm Piano Studios website.

 https://hurstwoodfarmpianos.co.uk/newsandarticledetails.php?page=news&catid=1&atid=16

Clearly it is not just a carbon fibre soundboard in an otherwise conventional piano as has been suggested. 

[regnistep]

I did see a picture of that all-carbon piano.  That was quite an accomplishment.  I assume there is some steel in there somewhere to provide some mass where it is needed.  If there is some more detail you feel comfortable sharing with me, either published papers, or submitted patents, I would like to look through it.  Because, I genuinely don't want to waste my time doing what has already been done, or do something only to find out it has already been patented, and I really don't want to mislead the people that contribute to the project.  But based on what I can see in the various pictures on the internet, we are doing something unique.

[faulty_damper]

I'm surprised someone has already beat me to the all CFCM piano...   Looks kind of ugly, though.

When the soundboard is produced, will it have a clear-coat?  A clear-coat may absorb some of the vibrations.  Also, a painted CF soundboard will also have a different sound, based on what I can tell with the Luis and Clark carbon fiber string instruments.

[richard black]

Well, this is all very interesting stuff. I have played (briefly) a Phoenix Steingraeber and I found it an impressive and fascinating instrument. But I'm sure there are plenty of other ways to do the carbon-fibre thing, each with its own merits and character, and I look forward to hearing the results in due course. I know a lot of piano people are all too ready to indulge in 'mine's better than yours' type argument but for me one of the great joys of playing pianos is that so many of them are highly individual, but perfectly valid and capable, musical instruments. I'm sure the use of carbon fibre won't alter that particular situation.

[thalbergmad]

I'm sure the use of carbon fibre won't alter that particular situation.

Indeed it won't. Use of carbon fibre has even reached the banjo World and it has yielded some pleasing sounds.

Thal

[faulty_damper]

I hear that the best part about carbon fiber instruments is that they float.  A Luis & Clark carbon fiber cello was caught in a flood and, after replacing the wooden bridge and sound post, played perfectly.  Will a carbon fiber piano float, too? Definitely wouldn't have to worry about humidity.  

[thalbergmad]

It will be interesting if this catches on. 15 years ago, the chap at my local bike shop told me that carbon fibre bike frames were just a fad and steel would always be the preferred material. Now, I have a bike frame that weighs under 800grms and can easily support my fat butt and I would have thought that as prices come down, carbon will completely replace steel and aluminium.

Carbon fibre snooker cues never seriously threatened the use of maple or ash. I had one once and it was bloody awful.

Perhaps in 20 years time, we will all be playing carbon fibre pianos. Only time will tell.

Thal

[faulty_damper]

The key sticks should be carbon fiber so that far less energy is lost.  Also, there is a company that makes carbon fiber bicycle wheels with carbon fiber spokes. So perhaps steel strings can be replaced by CF, too!

[thalbergmad]

Also, there is a company that makes carbon fiber bicycle wheels with carbon fiber spokes. So perhaps steel strings can be replaced by CF, too!

I do have some carbon wheels with carbon spokes, but the spokes do not ring when you ping them, so perhaps strings will always be steel.

Thal

[chrisbutch]

I do have some carbon wheels with carbon spokes, but the spokes do not ring when you ping them, so perhaps strings will always be steel.

Thal

As another member of that very special sub-freemasonry, the pianist/cyclist (or rather the cycling pianist), this gives me an excuse to point out the close similarities between wheelbuilding and piano tuning. The spokes have to be brought to a uniform tension while keeping the rim laterally true and perfectly round, the tension often having to be set differently for spokes emanating from the different sides of the hub (this depending on the 'dishing' of the wheel to accommodate a gear cluster etc). The skills necessary to do this well are impressive and hard-won, and crucially involve the tuning of the spokes to a uniform pitch, so you will hear the constant 'pinging' of plucked spokes as the wheelbuilder works. Most of my wheels are tuned with the two sides about a major third apart, usually E flat and G

It's true that carbon spokes at the moment are pitchless. But I don't think that necessarily means a carbon piano string is impossible. From what I understand of the manufacturing process, cf can be given more or less any physical characteristics by variations in the laminating structure. To achieve a pitched string, that would presumably mean all the fibres oriented in the same direction. But perhaps that would compromise strength. I'm only guessing here.   

[thalbergmad]

Most of my wheels are tuned with the two sides about a major third apart, usually E flat and G

I have definitely learned something new today. It has never occurred to me that wheels were tuned.

I think this is wonderful. I could tune my old wheels CGBD x 6 and have a revolving banjo.

Thal