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 Radio
control is a virus. It infects hobbies and hobbyists. All you have
to do is compare model aviation in 1955 with model aviation in 1975, and
you'll understand the blinding speed with which the epidemic spreads. Move
the time scale forward a few years and you see how model cars and boats succumbed
just as quickly. Today, it's virtually impossible to imagine any of these
hobbies as they were before R/C. Tomorrow, the same will be true of model
rocketry. The day will come when it will be hard to imagine a time
when rocketeers cast their hard labors free to drift as they might.
What awesome immune system has protected model rocketry this long
from infection? For a long time it was the size, weight and cost of
radio systems. Pioneers flew radio-controlled rocket- and boost gliders as
long ago as the sixties and seventies, but were forced either to lash together
delicate custom receivers and actuators or to pay a premium for specialized
"micro" equipment. Those days have passed, thanks in part to the loss
of R/C flying fields across the country and the resulting rise of the backyard
flier. Anyone can now purchase micro equipment for half the cost of the
"standard" equipment of a few years ago. The remaining obstacle is
pure psychology.
Radio control exists in the hobby today mainly in international
competition. These models have been honed to an unbelievable level of refinement,
and demand piloting skill of compatible quality. Models like this shine
at the very leading edge of both model rocket and model aviation technology.
Unfortunately, they also give many the impression that the only way a model
rocketeer can enjoy radio control is to master building, adjusting and flying
such advanced models. In addition, it is often recommended that a hobbyist
should take up propeller-driven model airplanes or tow-launched gliders before
even attempting radio control in model rocketry. It's not surprising
that few even make an attempt on, let alone successfully run, this gauntlet.
Within model rocketry, radio control has remained the province of the
small dedicated cadre of master international competitors.
The hobby cannot, however, fend off the epidemic forever. As
with any other class of model, radio controlled vehicles that aren't intended
to compete with the best in the world do not have to be complex, challenging,
sensitive and intimidating. The "weight penalty" associated with today's
radio technology is so small that basic designs and ordinary materials like
wood and paper can provide more than adequate performance for enjoyable flying.
In the next few years simple models like this will begin to emerge.
Radio control technology is such that equipment could be added to many basic
models without a noticeable weight penalty. Such models could use ordinary
materials like wood and paper and could be easily lifted by black powder
rocket motors. These models can also easily subdue the requirements for pilot
skill if they are designed, like all other rocket-launched models, not to
be guided during the rocket boost.
I believe Arcie II is a prototype for such a model. It will
have been successful if it is followed by other similar commercial products
and hobbyists' personal designs in the coming years. I'm quite sure
that, as in every other hobby that has been touched by radio control, hobbyists
that sample radio control will find themselves unable to give it up.
They'll continue flying everything the hobby has to offer, but part
of them won't quite be able to remember what it was like before they were
capable of controlling the models sailing above their heads. No pill's gonna
cure their ills.
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What it Takes
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Designing Arcie II
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I'm convinced that you're ready for Arcie II. I'm about to describe
the equipment you'll want to acquire, then you can go on to the
Purchase Page and track it down. Of
course, you need the airframe and booster system, which, beginning in
mid-July, you can obtain directly from the Edmonds Aerospace. You'll
complete Arcie II's all wood and paper construction in less than two
hours.
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Then you need a radio system, and here you have a few choices. They
sound complicated, but this is standard equipment that is familiar to every
hobby shop owner or web hobby dealer. A modern radio system consists
of a transmitter on the ground and an "airborne pack" consisting of a radio
receiver, a battery and "servos" to move the control surfaces. The
airborne pack for Arcie II requires one HS-55 servo and a Feather Receiver,
both products of Hitec RCD. The battery pack must be either a four
cell 50 mah (milliamp-hour) NiCad (nickel cadmium) pack or a four cell 120
mah NiMH (nickel metal hydride) pack. Any other battery not only wouldn't
fit, it would make your model too heavy to fly. The easiest way to get all
of this right is to buy the complete set of gear for Arcie II that is offered
by the Balsa Machining Service, which can be reached from the purchase page.
No matter where you buy your gear, you are almost always better off to buy
the receiver, servo and transmitter as part of a single package, even
if the package contains extra servos. Think about what you plan to do in
the future. If you intend to one day fly electric airplanes, you probably
should select a package with a four-channel transmitter. If you stay within
rocketry, you might make it through your whole career with a two- or
three-channel unit. Usually such sets do not include a suitable airborne
battery, so you'll have to get one separately.
Finally, you need motors and a way to launch. Even though the
model can use the C11-3, D12-3 and E9-4 motors, I want you to use the D12-3
for your first flight. The key to easy beginner flying is to get it
right straight up over your head with altitude to spare, and nothing does
that like the D12. You can actually launch this model from a conventional
model rocket pad with a 3-foot rod 3/16" in diameter. A safer setup,
though, is to obtain a four-foot rod, to allow for the portion of the model
that hangs down below the aft end of the booster tube. Another alternative
is to mount a three-foot rod in the end of a dowel to hold it above the
ground.
Consider the equipment you buy to fly Arcie II an investment. As more
radio-controlled models appear in the future, you can move your radio gear
from plane to plane. One day you'll be flying two-channel aerobatic
ships, or three-channel thermal cruisers that will float around all day.
Head to the Purchase Page and start
this party.
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What's with the "II", anyway? Well, way back a long time ago,
in the mid nineties, there was another kit, just a few years ahead of its
time, named Arcie. It spanned eras in so many ways. Designed on a computer,
but machine cut by hand on a band saw, it carried around bulky old "standard"
radio gear just as the new micro gear was appearing on the scene. Foam and
fiberglass had already worked their way deep into model aviation and rocketry,
but Arcie's balsa built up wings and box fuselage made it a construction
challenge quite different from anything that even advanced rocketeers were
used to. Everything was sacrificed to make it easy to fly during glide, but
as wood densities varied, the D12-3 motor sometimes struggled to lift the
immense stack. Still, Arcie was a joy to fly, extremely stable with a glide
that wouldn't quit, but in the late nineties, the shop that did the machine
cutting, one of the last in the United States to do so, finally went out
of business.
I always knew that there would be an Arcie II, and it would carry
with it the important virtues of Arcie, but to emerge, it need to step fully
into the 21st century and shed a couple of the burdens carried by Arcie.
The new kit would definitely inherit the detachable boost pod, but
everything else was up for grabs. Slowly it came together. Certainly the
new kit would be smaller, taking advantage of the micro radio gear, now about
as cheap as Arcie's ponderous standard gear had been. At first it looked
like a shrunken Arcie. Slowly I realized I had to attack Arcie's main
problem head on. Plenty of experienced modelers had bought Arcie kits,
but hadn't finished building them even years later. I realized that
the builder had to be able to finish the model in a single session, or it
would end up on the project shelf. I attacked on every front. "What
doesn't a single channel trainer need? What slows people down when they're
building." This thinking replaced the built up wing with a solid
pre-airfoiled sheet, and pared the box fuselage down to a single thick slab
cut to fit the gear, with a simple tube fairing to streamline things.
Eventually came the mental victory that made Arcie II what it is.
I realized that, by sticking with the conventional configuration, I could
mount the servo right underneath the roots of the ailerons, where it could
use simple, shaped wooden paddles to move them. Not only would this eliminate
the tedious process of hooking up control linkages, it would allow me to
permanently droop the ailerons and to bias their deflection.
Arcie II's ailerons are biased so that the down aileron deflects more
than the up aileron, acting like automatic up elevator when the model enters
a turn, to keep it from speeding up. Thanks to the permanent droop, the ailerons
act as flaps, making the wing work hard to slow the model down, at some cost
in glide ratio. A slow glide with a fair slope is exactly what a beginner
needs when trying to guide a model back into a field.
From there, everything slowly collapsed into place. The new gear knocked
the fairing tube down to under an inch diameter from over an inch and a half.
Flight test showed that a 24 mm booster pod would result in impeccable boost
behavior, and that the mighty wing centersection joint could stand up to
the E9-4 motor as the model was reduced almost to a speck. We've ended up
with a model that climbs high and straight, and descends slowly but purposefully.
It's actually slightly less stable than the old Arcie, but the great boost
altitude and visibility more than make up for that to help the beginner makes
trouble-free first flight. The secret though, comes down to this:
you will not fear flying this model. I've cut your investment
of time and labor back so far, you won't be walking on eggshells when you
go out to make your first flight. After three years of careful thinking
and careful testing, Arcie II is ready for you.
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Arcie II