This shows what happens when things go wrong. You can see where the heat-shrink tubing was
not tight enough against the hard carbon-fiber side frame. Toasty!
The author’s Raptor E700 is a great example of keeping wires safe.
I’ve always felt that wiring a helicopter is an art form. It’s the job that takes me the longest when
I build a helicopter. I tend to agonize
for hours about which way to route
a particular wire and the best way to
secure it in place, making sure it isn’t
rubbing against any hard corners.
I’ve learned—and seen—many
approaches to wiring, and I am pleased
at the end of a build to see it neatly
Aside from the pleasing aesthetics,
there is a functional side to taking
that extra step with your wiring. By
carefully and thoughtfully routing
your wires, you can avoid chafing and
faulty wires, making it easier for you to
remove a component without getting
lost in a rat’s nest of unkempt wiring.
We’ve all experienced what can happen to a neglected wire in a helicopter.
One instance springs to mind, and it happened when I was flying a 700-size
electric heli. During this particular flight, I noticed a smoke trail coming from the
After an immediate landing and a frantic run to where I had landed, I saw a
flame licking out from underneath the canopy. My immediate thoughts were that
either my LiPo had decided to erupt or I had fried my ESC, but I never would
have guessed what had actually happened.
I carefully, but quickly, pulled off the canopy and my knee-jerk reaction was to
blow out the flame. To my surprise, it extinguished on its own, which eased my
mind about the
possibility of a
LiPo fire. (You
would never be
able to blow out a
I looked at the
ESC, which was
in perfect shape.
I looked closer at
where the flame
had been, and
found a brittle,
of carbon-fiber side frame that had been setting underneath my three main motor
After more investigating, I found that the heat-shrink tubing that I had used
around the motor and ESC wires had rubbed away, along with the second layer
Safe wiring is essential
of heat-shrink tubing that sealed the
connectors. With the wires bare, the
carbon-fiber side frame had acted as a
conductor and I had “cooked” the resin
out of the carbon fiber. What remained
was a powder-like substance that
crumbled to the touch.
What surprised me was that
although I had taken great care
routing wires around corners, I hadn’t
considered the area where the wires
laid across a flat piece of the side frame.
I had doubled the heat-shrink tubing,
but that hadn’t been enough.
Now my motor wires are secured
with additional Velcro wrapped around
them (soft side against the wires), with
plastic zip ties holding it all in place.
I use a number of methods to
keep my wiring safe. There is a fine,
expandable, plastic wire-mesh available,
which slides over any servo wiring. It is
available in many colors and can be cut
to length. The ends are secured with
a small piece of heat-shrink tubing.
I think the mesh looks cool, but it is
also functional. It will protect your
servo wires from chafing, and is perfect
117 Model Aviation APRIL 2014