Mar - Rcsoaring.com

as epoxy resin. We use it extensively in
competition models of all types to gain
structural strength and rigidity, plus it’s
just cool! Understand, first, how this stuff
is made. To make a very long story very
short, you make this stuff by burning
rayon and poly type fabrics down to
nothing but the carbon that it is based
on. It takes tremendous heat and some
high pressure for this to happen, but
in short that’s what they do. Carbon in
itself is an atomically light material, but
when compounded with other elements,
it becomes not only very dense but
conductive to electricity. The conductive
stuff is more or less what we end up
using in our models. Because it is dense,
and conductive, it does two things to
the RF signals of our radio systems.
The first is that it will block the signals
from penetrating the material. It not only
deflects the signal to a degree, but it also
absorbs the signal using the electrical
conductive properties it possesses. That
second property of carbon fiber is one
of the reasons it is used extensively in
“stealth” aircraft. So, that being the case,
you can now understand why it’s not
good to place a carbon fiber structure
between the radio Tx and the Rx. That
signal just ain’t going to get through
completely intact.
Okay, so we have that fact of life down,
and if you need to prove this to yourself,
just try it out and you’ll see. It’s an
easy experiment. Just remember that
a ground range check proves nothing
when it comes to carbon fiber. This leads
us to our first experiment, only this one
was originally done in 72-Mhz form.
The situation is that we want to keep
from having antenna wire hanging out
of our wonderful, aerodynamically clean
sailplanes, because the wire produces
drag... and it looks ugly! At this time,
most of the competition planes were
using a significant amount of carbon fiber
(CF) in the construction of the fuselage to
keep them light and also to give them the
strength to withstand the typical “dork”
landing.
This is an Onyx 3.5 meter model and although the photo is small, you can clearly see
the black, carbon fiber tail boom. In reality, the 72-Mhz antenna is wound around the
tail boom on the outside of the boom. In this case, it did work, but the antenna suffered
damage almost every time the plane landed as the fuselage scraped along the ground.
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