ROTORSPEED
TEXT & PHOTOS BY PAUL TRADELIUS
High-performance helicopters like my Raptor 90 3D rely on equally high-performance servos for maximum control and performance. Choosing the right servo for your helicopter is like having an insurance policy to protect your investment for many flights to come.
SERVOS: Make the right choice for your helicopter
YEARS AGO, NE W RADIOS CAME WI TH FOUR SERVOS. These were not standard servos, or high-speed servos or high-torque servos, but just plain ol’ servos. That’s all there were, and we were very happy to have them. Early radio manufacturers also used a specific color so their radios could be easily identified from a distance. Those of you who are old enough, may remember that EK Logitrol was red, Kraft was gold and
Orbit was black. These radios were all
designed and made here in the USA, but
unfortunately, they have not been available
for many years.
These first generation servos also came
in various colors to match the rest of the
system, and there was no standard size,
mounting method or mechanical output.
By comparison to today’s servos, they were
very slow and didn’t have a lot of power (we
didn’t even have a spec for their output
speed or torque). We were just happy that
they moved in unison with the transmitter
sticks.
Fast forward to our modern spread of
servos, and we find so many different variations, it’s hard to tell them apart, as well as
choose the right servo for our helicopters.
However, one of the differences that’s easy
to spot right away are the many sizes of servos available. Some are extremely small
micro servos for the smallest of helicopters,
while others are full size with power and
speed for the most demanding helicopter
applications. Add this to the growing trend
of not including servos with new radios,
and it’s no wonder the average flier has difficulty in determining which servo is best to
buy. This is not to say that only one specific
servo will work with your helicopter and
type of flying, but rather that you should
look closely at the specs of all the servos
available, and choose wisely to determine
which will give you the most bang for your
buck. And in these economic times, that is
becoming more and more important.
THE RIGHT CHOICE
The size of your helicopter will determine
the physical size of the servos you’ll need to
use. However, if your radio came with
entry-level or sport series servos, it may be
best to upgrade to a better-performing servo
right away. Sport servos are intended for
limited performance applications and contain the least expensive components to
keep their price down and make them competitive in the marketplace. As a general
rule, they are not well-suited to helicopter
applications.
Since I’m certainly no expert on modern digital servos, I called Hitec RCD and
talked to their servo expert, Mike Mayberry,
to get the technical information for the rest
of this article. And the first question I asked
Mike was, “What are we getting in these
