Sunday, June 6, 2010

More materials for reeds and bocals

I previously wrote about a successful synthetic clarinet reed, based on a anisotropic polymer. They aren't the only one, Fiberreed is another, based on what they call a "Hollow Fiber Foamresin Compound", a composite of hollow fibers encased in foam to provide an appropriate balance of lateral and longitudinal stiffness. Sounds plausible. Some of their models incorporate carbon fiber, which interests me, since carbon fiber is one of the strongest and stiffest materials, and dominates a lot of applications. In addition to the usual benefits of artificial materials (no water absorption, longevity) Fiberreed promises reproducibility, and will custom adjust a new reed to match your favorite reed of any type, and then sell you a new copy anytime you want. Like Legere, Fiberreed is single reed only, which I'd guess reflects partly manufacturing simplicity, and partly market size -- there's a lot of sax players out there. Fibracell is another maker, again with a fiber composite, this one with Kevlar and resin, and there are likely more besides.

Bocals are also heavily affected by material, with makers offering a wide range of metal mixes and thicknesses, in addition to lengths and bore variations. (Heckel lists ~6000 stock combinations, even before you start asking about something custom.) Unfortunately, even the best makers seem to suffer wide variability among nominally identical bocals, so the usual advice is to try many, and try them blind as to maker and model. Other materials used include wood, from Paraschos, which seems to make everything out of wood (even clarinet ligatures!). As for carbon fiber, you can buy carbon fiber sax necks from Zen Composites, and Leonardo Fuks has made at least one carbon fiber prototype bocal, shown here. Hard to tell much about how well it works from that short clip, though.


  1. My former prof., Marc Vallon, has a carbon fiber bocal. It was one of a short run of them, although I'm not sure who the maker was (it may very well have been Fuks). I've played it quite a few times. It's wretched at the lower end of the horn, but it pops out high notes like no other - high Es (top space treble clef), Fs, and even Gs are a cinch, and I think I once played to the C above that without too much problem.

    A colleague and I spent awhile brainstorming and researching how we might make such a thing ourselves. But having no prior experience working with carbon fiber, we gave up rather quickly.

  2. Very interesting, thanks for the comment! I think they would not be easy to make. Metal bocals get bent after forming, but that wouldn't work with carbon fiber. So I guess you would have to form on a prebent mandrel, but then how would you get it out? It could be flexible, made of joined disks, say, or it could be temporary and nonreusable, like a lost wax casting. Neither choice seems attractive. Another option might be to wrap carbon fiber around a thin metal core, made conventionally. Interesting problem.

  3. Yeah, that was our big stumbling block. We decided our ideal solution would be to create a precise 3D model of the bore, have it realized in plastic on a 3D printer, then be able to melt the mandrel after the resin had set on the fiber. We'd then be able to easily produce exact mandrel copies. That, though, was certainly a pie-in-the-sky solution, as we neither have experience with modeling software or access to a 3D printer.

  4. I've thought about the 3D printing option. The resolution isn't great, about 0.1 mm vertical on the one I have access to, which is fine to look at but I don't think enough for acoustics. (Maybe after sanding it'd be fine.) The material is plaster, which I think would be hard to remove as an interior mold. Cost is reasonable, though, ~$30-40 per prototype, and sorting out the modeling doesn't sound impossible.

    Or: master interior mold -> silicone exterior cast -> low melt disposable metal interior mold -> composite final, cure, then heat to remove metal mold. Complicated, and I have no idea what kind of precision you can get out of a silicone mold.

    Maybe lots of metal disks fixed to a stiff cable would work, allow forming in a bent shape, and still be removable.

    Did you look into bore shapes at all? They clearly matter a great deal, but I haven't seen much on exactly what and how.