Right: Bob Frogner’s experimental model for .15 Profile
Carrier is an old Sniper converted from glow. He lets it all
hang out rather than modifying the model for internal
battery and controllers.
Pete Mazur finished on top with his
electric-powered Skyray.
Skyray and .15 Profile events were
chosen as the first test cases for electricpowered
Carrier because the speed limits
imposed in those events make power much
less critical for overall performance. With
the speed limit it was believed that
electric- and glow-powered models could
compete more or less equally.
The real advantage to electric power is
simplicity. Electric power is easier for
someone who is new to the technology to
set up successfully, whereas glow engines
can be challenging to get the fuel tank and
throttle optimized—especially for
someone who is new to throttled engines.
The electric-power configuration is
relatively consistent from
model to model, with the
usual variations in
details of equipment
A look at electric power for Carrier models
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Control Line Navy Carrier Dick Perry
Top right: Pete Mazur’s winning Skyray model at Sig contest.
Battery goes in outboard wing bay with ESC, servo controller,
and data recorder (optional but nice for experimentation)
inboard.
Above: Mike Anderson’s Skyray uses metallic-case batteries
(removed for charging), which can be less expensive but weigh
more. Bob Frogner photo.
IN THE LAST column I promised to report on the first contests
in which electric-powered models competed in the Navy Carrier
events. However, the first event didn’t take place as early as I had
hoped.
Two contests in Iowa were scheduled in May and June, but the
May event suffered from weather that kept the Carrier models
grounded. Things worked out better for the Sig contest in June.
Sig originated the Skyray Profile Carrier event and allowed
electric power in it as an experiment this year. Several electric
Skyray models competed against entries with conventional power.
I’ve included photos of some of the aircraft and their power
systems.
Not all models were flown successfully, with problems with the
conventional control systems (not the electric-power portion) and
the expected issues with new airplanes and new ideas. In the end,
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such as motor and battery brands. That’s
the same variation that exists in the glowengine
events.
Most of the electric models are using
outrunner brushless motors and Lithium
rechargeable battery packs. Most batteries
are Li-Poly for the weight advantage, but
Li-Ion batteries are also used.
Most installations use pusher propellers
to improve low-speed handling. With
electric power, the only difference between
left- or right-hand rotation of the motor is
in how the electric leads are connected to
the motor.
The accepted method for speed control
on the models seen so far in the events is a
single-channel electronic servo controller
by Clancy Arnold driving the ESC.
Clancy’s controller is simple and light, and
it can be powered by the battery eliminator
function of the ESC if it is so equipped.
The controller uses input from a 10,000-
ohm potentiometer for control.
In the original design Clancy intended
the potentiometer to be on the handle with
electricity running through the lines. Most
Carrier modelers are finding that a
conventional three-line control system is
simpler, with the usual mechanical throttle
output going directly to a control horn on
the potentiometer shaft.
With that type of control configuration,
existing glow-powered models can be
converted to electric for those who want to
experiment without building a new model
especially for electric power.
Propeller size and pitch don’t seem to
be overly critical for most electric models
that are being flown so far. The outrunner
motors are high-torque designs that turn
relatively slowly compared to brushed
motors and inrunner designs. The result is
that the propellers they use are larger in
diameter and higher in pitch. Starting is
greatly simplified; the only required action
is to insert the arming plug.
The finish on electric-powered Carrier
models can be whatever you want to use—
including spray paint from your nearest
hardware store or even latex from the last
time you painted your house.
The only thing you’ll have to clean off
the model is oil left by the other
competitors’ glow engines that it might
pick up from the deck. MA
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