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Starting
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Radio
Control Models & Electronics - Jun '94
by
Stan Yeo
INTRODUCTION
This
article is for those occasional readers that are interested in taking
up radio control model flying and more particularly slope soaring
as it is my speciality. Two recent events finally persuaded me to
put pen to paper, one was the interest shown by youngsters and their
parents in flying model aircraft on a 'Young Engineers' evening
at a local secondary school. The second was a chat I had with BARCS
(British Association for Radio Control Soaring) officials at last
years Sandown show re the age profile of competitors in the BARCS
flat field glider events. They were concerned about the possibility
of competitors collapsing whilst towing up gliders on no wind days.
Both conversations made me think about the accessibility of our
hobby to prospective enthusiasts hence, this article.
WHAT
IS SLOPE SOARING ?
Slope
or hillside soaring is where the aeroplane, model or full-size,
is kept airborne by lift generated when the wind is blowing on to
the face of a hill or cliff. The air, unable to go through the hill,
is deflected upwards and over it. The lift generated is dependant
on the size and shape of the hill, the terrain in front of it and
of course the strength of the wind. If the wind is too light it
does not produce very strong lift but likewise, if the wind is too
strong the lift gets 'flattened' making it difficult to fly the
lower performance models (see diagrams below).
IS
IT EXPENSIVE ?
Slope
soaring is the least expensive form of radio control model flying.
It does not require expensive engines or radio control equipment.
It is possible to get airborne with new equipment for less than
£100. For this you can buy a basic trainer model and a 27 Megahertz
2 channel set of radio control equipment with 2 servos. Most modellers
would advocate a slightly more sophisticated set of R/C equipment
for reasons to be outlined later, but on a recent visit to Wales
I met a group of modellers who had been using 'such' equipment for
a number of years and were more than happy.
Running
costs are also low, typically £10 a year for insurance (an absolute
must these days) plus your club subscriptions. These can be as low
as £5 a year to £20 plus if the club has to hire a room for club
meetings and/or rent has to be paid for the flying site. Some clubs
provide third party insurance cover inclusive in their membership
fee. Most modellers build one or two models a year. The least sophisticated
of these will cost around £50 to build from a kit, a little less
if built from a plan. There are more sophisticated models available
and most modellers do progress on to them but only after they have
learnt to fly. In addition to insurance club subscriptions and replacement
models there is of course the cost of driving to and from the flying
site but this applies to most leisure activities.
HOW
DO I START ?
As
with most leisure activities the best way to start is to visit the
local shop specialising in your leisure activity in this case the
local model aircraft shop. There is a model shop directory in the
back of this magazine. Most model shops have a list of clubs operating
in the area along with contact names and telephone numbers. Building
and flying model aircraft is not easy but it is well within the
capabilities of most people. Success is almost assured if help and
advice is sought from a competent modeller. You will need help in
selecting the right model to build, building the model and most
importantly learning to fly it. Whenever a modeller is in the company
of non-modellers there is invariably the story about a modeller
who spent ages building an all singing and dancing model aeroplane
only for it to crash on it's maiden flight. These crashes unfortunately
do happen but very rarely and far less frequently than the non-
modelling public perceives. It is rare for a novice's aeroplane
to be written off on it's maiden flight particularly if that novice
has sought help from an experienced modeller. My experience suggests
that model flyers do not generally start seriously damaging models
until they have gone 'solo' and are flying more aerobatic machines.
Having
made contact with the local club find out where they fly and when
and where they hold their clubs meetings. If you have a choice of
clubs it goes without saying that you join the one that is more
interested in your type of flying. All clubs will do their best
to help novices but please remember that most people are inherently
shy and consequently you may have to ask for help!
CHOOSING
THE MODEL
Subject
to the advice of the club you have joined my advice is that you
build a simple, rugged, watch it bounce, Rudder Elevator model of
moderate span (1.5 metres) that is easy to fly. Up to a point the
'boxier' it is the better. Some people will disagree with this advice
but it is a result of teaching many people to fly over more years
than I care to remember. Basically, novice flyers are invariably
novice builders so the model must be easy to build and repair should
the need arise. It should also have a relatively low flying speed
range, fast enough to cope with the strong winds but 'draggy' enough
to be speed limiting when things go wrong and the model is plunging
earthwards. It is at these moments that 'thinking time' is at a
premium and this is when that extra drag could make the difference
between a recovery and a crash. Smaller models are generally more
manoeuvrable than their larger counterparts and this is important
when the 'ab initio' pilot has got past the stage of 'steering'
the model around the sky and on to the stage of learning to fly
instinctively. This can only be done by throwing the model around
the sky and honing your reactions under pressure.
There
are a number of good trainers on the market and three that I have
knowledge of are the Soar Ahead Sailplanes 'Ace', Chris Foss's 'Middle
Phase' and the Phoenix Model Products 'Ab Initio' and 'Stage Two'.
There are others and no doubt the editor will hear from the manufacturers
of those not mentioned!
CHOOSING
THE RADIO EQUIPMENT
Unfortunately
the most economic route is not the recommended route for most modellers
i.e. the 27Mhz, 2 channel, twin stick sets mentioned previously.
Information from the 'trade' suggests that at least 85% of all model
flyers fly with the primary controls on the right-hand stick. The
primary controls are Elevator and Ailerons or Rudder if ailerons
are not fitted. Modellers are very reluctant to fly other peoples
models if the control stick configuration is different from the
one they fly. It is like driving a car with the clutch and brake
positions reversed! It is recommended therefore that you buy a 4
channel set with the Throttle control on the left-hand stick. This
obviously increases the initial cost but it cannot be helped. The
cost is further increased as it is recommended that you buy a set
with rechargeable batteries. The extra cost is soon recouped however
after just a few flying sessions as dry batteries are not that much
cheaper than rechargeable batteries. They also give added confidence
knowing that the model is less likely to crash through battery failure
providing of course that the batteries were charged in the first
instance. Most 4 channel sets are available with any number of servos
but it is recommended that at least three servos are bought so that
one is available when a three function aileron model is built. Most
model glider pilots fly on even number transmitter frequencies.
Some clubs insist that members adopt this protocol so it may be
advisable to check this out before you buy the radio control equipment
otherwise you may find that you have to buy an extra set of crystals
on an even numbered frequency. Modern radio control equipment is
very reliable and is therefore a matter of personal preference so
other than choosing a set with adequate servicing and spares backup
no recommendation is made.
Well,
I hope you found this article of value and you are tempted to have
a go. Even if you are still undecided make contact with your local
model club and have a chat with the members at the flying site.
You never know they may even persuade you to fly one of their models!
DIAGRAMS/PHOTOS
Airflow
over a slope
Transmitter
configurations
Photographs
of a selection of trainer type models and radio installation
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