I came across one, Carbony, and it looks like there are significant advantages to using it as the material.
This makes me wonder why they are not catching up as fast (even as fast as Delrin), and/or why not more makers are adopting these.
Are there any major concerns?
I’m not convinced of the advantages over, say, delrin. Carbon fiber would I think be lighter, but there’s a lot of epoxy or glue in any carbon fiber object which I think might have a dampening effect? The strength to weight ratio of carbon fiber doesn’t seem to me to be all that crucial in a flute compared to, say, a guitar soundboard which has to resist the pull of strings for decades
I have an F carbony that I enjoy a lot. There is a youtube video of Sean Gavin playing one out there somewhere. I have often thought I’d buy a low D if I were in the market for a travel flute. They are light play easily.
I have a F and G whistle as well. I enjoy them very much.
Not sure why it isn’t more popular. Maybe its a challenging material for the flute maker to work?
Carbon fiber is certainly very sturdy and seems to be pretty adaptable for complex shapes.
As far as weight goes, my carbon fiber keyless flute is quite a bit heavier than my delrin keyless. I suspect that’s mostly due to the heavy stainless steel slide and rings on the former, versus silver on the latter.
I’ve seen other instruments made with it such as guitars and its a lively acoustical material. Rob Gandara does quite good with his instruments and I am pleased that he has a reachable low whistle with these. I looked into it myself once but decided I didn’t really want to be around the sheets nor the raw epoxy resins used. I am now using Urethane acetate resins for the 3d printing which are considerably less toxic than the epoxies in the uncured form. Someday I would like to see Rob’s shop and how he does his instruments.
Casey
I believe he uses a shaped mandrel to form the carbon fiber “wet,” which automatically shapes the bore. It machines just fine, but I would be hesitant to work it dry without an excellent dust scavenger - aerosolized carbon fibers are not something you want in your lungs.
I think the reason it’s not popular is simply due to the fact that wood is “good enough” for most cases. A lot of instrument makers started out as craftspeople or engineers, and they tend to work with what is most comfortable or familiar to then.
Plus, most people don’t have a Boeing hookup where they can get it for $2 a pound. I think it will be great for making the “cannoneer” Flemish-style drones more comfortable on some pipes I have planned. Maybe I can give the 3D printed chanter a surface wrap to make it match…
Resistance to synthetic materials by consumers may also be a factor. Some of us just prefer the aesthetics of a wooden flute. I admit it’s mainly an emotional attachment and not completely rational, but that’s how many purchase decisions are made.
I think the most important question is how it sounds.
Never played the stuff myself.
Carbon fiber flutes, at least the Carbony ones, aren’t exactly cheap, you know. List at $730, which is higher than at least some of the other non-wood flutes available. That’s also higher than some maker’s wood flutes. This might be one reason for a possible lack of penetration into the market. Non-traditional appearance could be an additional factor. Also, I’ve heard (no experience) that while strong in many applications, carbon fiber items can be prone to fracture upon impacts, more so than say, Delrin.
This is definitely a big deal. I was starting a line of Delrin headjoints for Boehm flutes many years back, and even though players admitted that they sounded great they simply didn’t want them because they were plastic. There were exceptions here and there, but the overwhelming majority of players wanted wood or metal. How the headjoint sounded was not even part of the equation–it was (as you point out) an emotional/philosophical decision. As time went on I also found myself having very mixed feelings about using Delrin (at one time I used a lot of it) and I’ve phased it out entirely except for making small flute parts on rare occasions. My decision was about waste, disposal and exposure to the fumes, dust, etc..
re: delrin
I find it to be pretty acoustically “squishy.” I own a delrin flute and a delrin set of flemish bagpipes, so it’s not like I reject the material out of hand, but stiffer materials transmit more of the resonance that comes when a note is really “in the notch.” Whether this translates to a different tone inherent to the material is up for (endless) debate, but as far as player feedback goes, carbon fiber and wood are much more “alive” under the fingers.
My customers are rushing rushing to order wood Folk Flutes before I change these over to 3D printed plastic. I’ve set a tentative deadline in a month or two - based on when I get the plastic ones up and running without trouble. I have way too many orders for the wood ones to fill usually and the effort is wearing out my joints - which is why I am going to plastic for the flute bodies. These will still be hand tuned and voiced.
If its a matter of aesthetics of wood over plastic, the choice of wood will still be available though a bit more expensive - I will simply be rebranding my $700 flute currently available in 3 or 4 sections as the Classic Folk Flute by Casey Burns and this will be available in other woods besides Blackwood and Boxwood - and also be upgradeable (keys, tunings slides and bands). The price will not change unless the Dollar collapses.
My Folk Flute model was always intended as an entry level instrument that plays well and is easy on the hands and embouchure. That won’t change. The choice of plastics and the possibilities of surface details such as going for a semi-translucent flute that is fluted and faceted like some of the glass flutes by Laurent are some avenues that I plan to explore soon. After some 2000 of these in wood, however, I am ready for a different medium - or an available apprentice! The one I had intended is stuck in Canada brewing beer for people to bathe in.
Casey
As a beginner, I’ve had nothing but positive experiences with my delrin flute.
Its a fairly subjective thing, I realize. But it sounds good (per my family); its light weight and easy to handle, and its virtually zero maintenance.
Two advantages for the beginner with a non-wood, low maintenance first flute:
- You spend all your time actually learning to hold and play the flute, not dealing with instrument maintenance
- You never wonder if you sound bad because the flute is reacting to temperature and humidity conditions. You just sound bad because you aren’t playing very well yet.
I’m pretty sure that Carbon fiber is indeed denser than delrin, that means that you don’t need as thick of stock for the same strength. If you made it using the same diameter as a delrin or wooden flute of a that design, it would be heavier.
When I compare the Carbony Flute that I own, to the other flutes I own, the Carbony flute has the thinest body at the first tone hole. The diameter is 1mm less than the Cochran delrin, 2mm less than the Copley Eb Delrin that I own. And even greater at 3mm on the Casey Burns ABW Rudall that I own.
As to the sound of the Carbony, Rob told me he based the design on the Pratten bore design, from drawings that Terry McGee sells, all my other flutes in D, are based on Rudall designs. I was wanting to try something different, more of a Prattern and the Carbony fit the bill. Over all I like to play the Carbony, for me it has a strong voice and I like the tone. I couldn’t say I like it better than the Cochran Delrin flute, so I still have both. Casey’s flute in ABW is my main flute, which I prefer over either of the others, but I’m not going to take it camping or some where it might get damaged, so that’s when I use either the Carbony or the Cochran flue.
The one thing I find with the difference in the diameter of the Carbony, is the transition from playing the Burn’s flute to trying to play the Carbony. The tactile feel of the flute takes some time to adjust to. If I were to go somewhere and wanted a back up flute I’d take the Cochran. So the Carbony is the Camping flute.
As Kevin suggested, I’m not feeling a great advantage of one over the other. I was able to work a trade with Rob, so it was worth it for me to give it a try.
MadmanWithaWhistle ~ Now every time I pick up one of my delrin flutes, you’ll have me wondering if it’s acoustically “squishy.”
I wanted to point out that when the Carbony flutes were being developed, there was some discussion here on C&F regarding fractures & breakage. From what I recently reviewed, the carbon fiber used is wrapped in a way that makes breakage extremely unlikely. The same may not be true for instruments using other construction techniques.
I have one of Geoffrey Ellis’ ebonite Pratten-style flutes, and really love it. Part of my interest in it was the fragility of wood–where I live there are wild fluctuations in temperature and humidity during the year. It’s light and feels very lively and responsive, and it’s extremely low maintenance.
It is hard to beat Delrin in many ways. I have two Delrin flutes, an M&E and Walt Sweet “Shannon,” and while I don’t like either one nearly as much as the Ellis, they were cheap and are easy to play and sound good. They both have a slightly “damped” quality compared to the Ellis, but I doubt listeners can hear that.
I’m intrigued by the resonance you get from ebonite. More noticeable than wood or Delrin. I get why Rockstro called it a superior material 
Just had this in an e-mail from a customer who bought an Essential flute from ebonite:
" I cannot imagine a more beautiful coloration of ebonite! But as you know, and have said, the real beauty is in its exquisite timbre. Perhaps the inherent elasticity of the natural rubber, and the homogeneity of the material, give it especially resonant qualities? In any event, it caused my music room to vibrate in sympathetic resonance in a way that I have
previously never experienced. "
Every time I pick up an ebonite flute I have this experience and it makes me wonder about the nature of the material. I don’t know that it’s a difference that is obvious to an audience, but it’s remarkable “under the ear” and under the fingers.
My experience with ebonite comes from the clarinet world, but it seems to me that the bore of an ebonite clarinet mouthpiece is much smoother than the bore of a flute made of ABW. Is it possible that the perceived difference in sound comes from the material’s smoothness, rather than the material itself? 
Achieving smoothness within an ebonite bore is actually quite tricky, especially if that bore is not cylindrical all the way through. I’ve had to develop a lot of technique in how I drill and ream it, involving multi-stage processes (some of which I’m even a bit secretive about!). The tricky part of drilling and reaming ebonite is that the heat from friction softens ebonite and makes it cut rough (micro-tearing of the surface), in much the same way that wood will do. A lot of the rather involved techniques I’ve perfected greatly reduce this, but a certain amount of sanding and polishing of the bore is still sometimes needed.
I think the smoother the bore is, the more responsive the flute, generally speaking, so I think that is undoubtedly part of the equation. However, in the case of ebonite there is something going on with the material itself beyond just how much polish you can achieve inside. Because I finish many of my wooden flute bores with clear marine epoxy, I’m able to give them a glass-like smoothness. I’ve achieved similar results using a polymerized linseed oil in the bore as well. In both cases (super smooth bores) the flutes did not sound/feel the same as an ebonite flute. The ebonite simply behaves differently. And this is not a “better” or “worse” type of evaluation of course, because the things I like about ebonite may not appeal to another player. It has a liveliness to it, and what I call a warmth and resonance, but to someone else that might be “buzzy” or “too bright”. Your mileage may vary.
The thinner the ebonite, the more I notice it. On my Essential Flutes, the walls are only about 3mm thick, and you can really feel the resonance. I just made a shakuhachi flute from ebonite, and while I can perceive some of that same quality, it’s not nearly as obvious when the walls are 7+mm thick.
But my own experience so far, having compared wood and ebonite side by side on a lot of different flutes, and I’m totally convinced that it is unique in it’s character as a result of what it is made of.
Thanks for your detailed explanation, Geoffrey Is it possible to achieve the same wall thickness (~3mm) with wood? I would expect that the thinner the walls are, the more resonant the instrument feels to the player, as you seem to suggest.