Got
the gear?
When
fixing the undercarriage in position, please make sure that the
wheels turn freely and that they do not exhibit any large degree
of toe in or toe out. If they do, remove the offending leg and
tweak it as necessary. Don't try and bend it whilst it is
attached to the model since you will most likely rip it away
from its wooden mount.
Steerable nose wheels should turn easily in their bearing
blocks. Make sure that the control arm is firmly attached to the
noseleg otherwise it will slip and and the whole thing may
revolve in flight or, in the worst case, it may even drop out
altogether! As with other control linkages, the pushrod to the
tiller arm should run freely. Pay particular attention here as a
binding noseleg can cause lots of battery drain and stress on
the poor rudder servo every time that you yaw the model.
Remember, the noseleg also turns in flight and not just when the
model is on the ground!
Models equipped with spats should be closely examined to make
sure that the wheels revolve freely. If the spat rubs against
the wheel, simple pare it away using a sharp knife until the
wheel is loose, making sure to allow some sideways clearance for
the wheel to move slightly along its axle.
Torque rods
Ailerons
may either be activated by torque rods or by independent wing
mounted servos. If the latter applies, you may find that the
ends of the rods that are connected to the servo are at
different angles when the ailerons are neutral. If so, the
pushrods will need to be of different length; in most cases this
can be achieved by simply adding a few extra turns to the clevis
on one side.
Some ARTFs will have been assembled in countries where the
climate is far different from our own. During transit and
storage the wood may have 'settled' and have distorted slightly.
This is most likely on unsupported parts like ailerons and
elevators, but is far less likely where the wood is bonded in
position as part of the airframe.
On the control surfaces, such distortions
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are
likely to manifest themselves as a slightly bowed or wavy
trailing edge. In most sport flying applications, they will have
very minimal effect on flying performance, but attention should
be taken to make sure that the controls are lined up more in
relation to the wing tips rather than the centre section. This
is because, generally, the outer sections of the control
surfaces have far greater aerodynamic effect than the sections
nearest the fuselage.
Engine bits
Most
modern ARTFs have pre-installed engine mounts, with the engine
lugs retained by simple metal straps. These have proved to be
very effective and secure, provided that care is taken to
tighten down the straps evenly and tightly. Such mounts also
allow a small amount of thrust line adjustment, which can be of
help when you are fine tuning your model during its early
flights.
Again, do check that the control linkage to the throttle
servo is free and take any necessary steps to relieve any
binding. In most instances all that will be required is a gentle
bend in the wire pushrod.
As with any model, take your time to set up the throttle such
that it gives full movement at the carburettor barrel without
stalling the servo, and that it also closes fully when the
throttle stick AND throttle trim are pulled back. This is very
quick and easy using a modern computer radio set, such as any of
the JR Propo range of radio control systems.
Radio bits
Hopefully,
you will have rectified any control linkage problems during
construction, but it's never too late to double check just to
make sure. Stalled or binding servos will quickly drain the poor
flight battery, leading to shorter available flying times and
potential servo failure in the long term. Your R/C system is the
heart of your model, so treat it with care. Protect against
vibration by wrapping the battery and receiver in suitable high
density foam and make sure that all servos are secured with all
screws (normally four), including their rubber mounting grommets
and brass 'anti-crush' ferrules. |
The
switch should be mounted either internally, where it can be
operated by a short wire pushrod, or externally, on the side
opposite the engine exhaust (if fitted). Take care to protect an
external switch from moisture in wet or damp conditions.
Final
furlong
Make
sure to set the control surfaces and centre of gravity as shown
in the instructions. These will not necessarily be the best
positions for optimum performance of your own particular model,
but will be sufficient to ensure a safe first flight. Depending
on your piloting skills, you may wish to change these settings
to suit your own flying style, but please do so one at a time so
that you can easily assess any changes to flight performance.
Novice pilots are advised to stick with the recommended settings
unless advised otherwise by their instructor, who will
preferably have been certified by the British Model Flying
Association (or its equivalent in your country). If you have
never flown an R/C model before, or have limited experience,
please do seek help from an experienced instructor. Your model
shop will be able to advise you of suitable model flying clubs
in your area who can offer flight training. Most are affiliated
to the BMFA, who are a national body dedicated to aeromodelling,
and who can also offer excellent third party insurance as part
of their membership package. For full details, please contact
the BMFA on 0116 2440028. (Non-UK readers will be able to obtain
details of their national equivalent organisation through their
model shop).
We hope that this article has given you some positive ideas of
how to get the best from your next Almost Ready To Fly kit.
Although most ARTF kits can be quickly 'thrown together' and
still fly, you will reap even more enjoyment from your new model
if you take your time during assembly to make sure that
everything is straight and true.
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