RC Helicopters - 2012/03

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www.ModelAviation.com March 2012 Model Aviation 115
rc helicopters
That brings to light the question of how long pilots stick with this hobby. If you
spend a few years involved with RC helicopters, it will become evident that many
pilots come and go. Helicopter enthusiasts seem to average roughly a two-year
stint before leaving the hobby. Continuing to fly helis may be too much work for
most people. It is fun in the beginning, but after a while, the newness wears off and
enthusiasm fades.
Sometimes burnout may be to blame, because the
competitive urge causes us to focus on keeping up with the
Joneses. Most pilots want to learn quickly, rather than just
relax and enjoy a steady progression of his or her skills. We
want to be good pilots now!
Imagine if you could integrate the RC hobby into your life as
more of a lifestyle that blends in. It might
provide more years of enjoyment without
disrupting other aspects of your life.
Helicopters are fun to fly, which
causes some people to become obsessed
with them. Then the dangerous cycle
begins; too much time and resources
are used to feed the heli obsession at
the expense of other important parts of
one’s life (i.e. kids, wife, job, etc.). This
situation can spiral out of control until a
cease-and-desist order is issued (that is a
business term that means an operation is
legally forced to shut down).
There are good online discussions
about the problems balancing life, jobs,
relationships, and helicopters. I have
been there, done that, and now realize
that balance is key.
Idle Helicopters
It is time to move on to some other
important things. Spring is around the
corner and many of us have outdoor
helis that are sitting around collecting
dust. Although we are in the midst of
the indoor season, I thought it would be
good to write about preparations for the
upcoming outdoor activities.
When your outdoor helicopters are
resting, it is smart to inspect them and
Hello and welcome. I hope this is not your first visit to MA’s little
helipad. Writing this column throughout the last few years has
been a rewarding experience for me. It is great hearing kind
words when I see many of you at events. Helicopter fliers are a good
group—the kind that you miss when they are gone. We are encouraging
and persistent. We have to be; otherwise, flying RC helicopters would
be a short-term adventure.
Learn to balance life
and hobby
by Mark Fadely
[email protected]
PLUS:
> Inspect idle
helicopters
> Fuel-system
setups
Mike Trueblood flies his T-Rex 700N at a fun-fly in Lexington KY. Mike is an Extreme Flight
Championships veteran with experience flying high-performance helicopters.make any modifications or adjustments.
Nitro helis are popular for outdoor
flying, but they need more care with
their fuel systems and have storage
requirements. Fuel that is left in motors
during the off-season can gum up,
causing issues when they are restarted in
the spring.
When you know that your nitropowered
helicopter will be idle for more
than a few weeks, run all of the fuel
out of the motor and fuel tank. Flow
some after-run oil through the motor to
prevent corrosion. If corrosion is present
during the first start-up, the engine likely
is damaged. The cylinder sleeve and
piston ring can be worn as the corrosion
is burned in the fuel mixture.
Fuel System Setups
Many pilots ask, “What is the best
way to set up the fuel tank on my
nitro model?” There are several options
available to deliver the fuel to your
motor with good consistency. When a
116 Model Aviation March 2012 www.ModelAviation.com
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helicopter is in 3-D
flight, G-forces cause
the fuel inside the tank
to go in all directions.
Imagine that you are
mixing lemonade. You
put the top on the pitcher and shake
it for a few seconds. Think about your
helicopter doing the same thing with
its fuel tank. As pilots, we ask our fuel
systems to perform flawlessly while
our helis fly in all orientations and at all
speeds—no easy task.
Let’s take a look at some examples of
fuel system setups. The oldest and most
common type is the muffler-pressure
setup. In this system, a line is run from
the muffler to a tap on the fuel tank.
When the motor is running it forces
pressure into the tank, which helps feed
the fuel to the carburetor.
The second type of fuel delivery
system is pumped. With this, a pump
with a regulator is located in the fuel
line. Generally, the pump is more
rc helicopters
consistent in metering fuel as the tank
empties.
The fuel clunk inside the tank is
one of the most important parts of
the system. For many years, clunks
have been made out of a weighted
metal designed to flop to any part of
the tank following the application of
G-forces. That works well, but there is
a new and better clunk.
The Fuel Magnet clunk does a
wonderful job of getting every drop
of fuel out of the tank, and it holds a
reserve of fuel so that the engine will
never quit, even if the clunk is not
drawing fuel.
James O’Neal, of O’Neals
Manufacturing, Inc. (OMI), developed
the Fuel Magnet. It is an aluminum
insert with an inlet hole that slips insidea small, foam doughnut. The foam
soaks up fuel and becomes saturated
and heavy, so it moves around inside
the tank with G-forces similar to a
traditional metal clunk.
The Fuel Magnet is great, but there
is one thing to watch for: the foam
is sensitive to exhaust gas. If you are
using muffler pressure in the tank, you
have to be careful not to leave the Fuel
Magnet exposed to the hot gasses after a
flight. The remedy is simple; refuel your
tank after a flight. The foam magnet will
stay submerged and won’t be affected
by the exhaust gasses.
There is the old-fashioned main/
header tank setup as well. I still use this
on some of my helicopters. It is a proven
system and never goes out of style.
Several top pilots still use it.
The idea behind a header tank is
to use the larger main tank to feed a
small auxiliary tank that feeds into the
carburetor. The header tank will retain
enough fuel, even when the main tank
takes in a little air. It is difficult to get a
tank set up so that the clunk will always
draw fuel.
There will be certain positions that
the heli can get into that will cause
the fuel system to momentarily run
dry. This does not create a problem for
the header tank approach or the Fuel
Magnet. Although the Fuel Magnet has
no header tank, the foam sponge clunk
retains fuel and continues to feed the
system in the event that it draws air. It is
an invention that works.
Give your fuel system a careful
inspection, and change it if it caused you
problems during the previous season.
Change of Seasons
I hope everyone enjoys the rest of
the indoor flying season. Don’t neglect
your outdoor models sitting on the shelf.
Preparing them for the new season will
pay dividends as the weather breaks. See
you here again next month.
SourceS:
International radio controlled Helicopter