Re: [Harp-L] Carbon Fiber Reeds, 3D printing, plastic metal adhesion technology...?

[John Ingham <harpjunky@xxxxxxxxxxxx>]

Dunno about coiled springs per-se but there are
these<http://en.wikipedia.org/wiki/Flex-Foot_Cheetah>'springy' carbon
fiber prosthetics that indeed store and release energy.

J


On Wed, Feb 20, 2013 at 12:43 PM, Vern <jevern@xxxxxxx> wrote:

>
> On Feb 20, 2013, at 12:06 PM, John Ingham wrote:
>
> > What can you tell me about the possibility of carbon fiber reeds,
> > products, experimentation. Is that just a crazy notion?
> >
>
> Carbon fiber has a very high strength-to-weight ratio making it ideal for
> many vehicle applications, particularly aircraft.  It has another desirable
> property in that the epoxy matrix absorbs vibrational energy.  However,
> these properties may make it less desirable for reeds which act as springs.
>  To my knowledge, carbon-fiber composite is not used for springs.
>
> In reeds, you want a material that stores, not absorbs vibrational energy.
>  The pitch of a reed is determined by the square root of (k/m) where k is
> the "springiness" of the reed near the rivet where it bends and m is the
> weight near the tip that deflects.  You would probably have to attach a
> weight near the tip of a carbon reed to achieve the customary pitch-length
> relationship.
>
> IF it were not for rust, spring steel would be the ideal material.  If you
> want to experiment, maybe a thin, protective coating could be developed.
>  Manufacturing spring steel and tuning would be problems to be solved.  The
> material that makes the best spring makes the best reed!
>
> Vern
>
>
>