GRAUPNER TAXI SPORT II Instruction Manual

1
Order No. 9586
9586.M
Building Instructions
TAXI SPORT II
For two-stroke engines of around 7.46 cc capacity
and
electric motors
This model requires a four-function radio control system
GRAUPNER GmbH & Co. KG D-73230 KIRCHHEIM/TECK GERMANY
Modifications reserved. No liability for printing errors. 12/2010
Made in Vietnam

2
Specification
Wingspan approx. 1600 mm
Fuselage length excl. spinner approx. 1190 mm
Wing area approx. 39.54 dm²
Tailplane area approx. 9.0 dm²
Total surface area approx. 47.54 dm²
All-up weight according to fittings approx. 2500 g
Longitudinal dihedral approx. 0.5 °
Downthrust and sidethrust built-in as standard
Caution: this model is not a toy!
If you are a beginner to this type of powered model, please ask an experienced
model flyer for help and support. If you attempt to operate the aeroplane without
knowing what you are doing, you could easily injure yourself or somebody else.
Please keep your safety and well-being in mind at all times.
Important: before you start construction
Even if you have already built a large number of RC models please read right through
these instructions and check that all the kit components are actually present. We
have taken great trouble to keep construction as simple as possible, without making
any compromises in the area of safety.
Check that the radio control system works correctly and at full range before every
flight: switch on the transmitter and the receiving system, and extend the transmitter
aerial to its full length; walk away from the model, and check that all the control
surfaces work smoothly and immediately at an appropriate distance; check also that
they deflect in the correct “sense” in relation to the stick movements.
If you are a relative beginner to this type of model flying, we recommend that you
enlist an experienced model pilot to help you check and test-fly the model.
RC system components and the control surface linkages must be installed at the
appropriate stage of construction, as it may be very difficult or even impossible to fit
them later.
When you are buying a radio control system it is important to ensure that the
transmitter and receiving system are designed for use with model aircraft, and are
approved by your national Post Office approvals authority. All RC units should
possess an FTZ series approval number.
Please remember that other radio systems and radio-frequency apparatus are also
permitted to operate in the frequency ranges used by model radio control equipment,
and there is no guarantee that your system will not suffer interference caused by
such apparatus.
Depending on where you operate the model, you may need to purchase a licence to
operate a radio control system for model aircraft on the approved channels in the 35
MHz band.
If you are not sure whether this applies to you, contact your nearest Post Office
Telecommunications office. Your local model shop will also have this information.
Note regarding the film covering
Minor creases or bubbles may develop in the film covering due to major fluctuations
in weather conditions (temperature, humidity etc.); in rare cases you may even find a
slight warp in a component. These minor faults are in the nature of film-covered built-
up wooden structures, and can easily be corrected using a heat gun, as commonly
used for modelling.

3
Creases: Blow warm air over the area and rub down with a soft cloth.
Wing warp: Hold the panel twisted gently in the opposite direction to the warp, and
apply warm air to remove the creases from the covering.
Caution! do not heat the film more than is absolutely necessary. If the air or the
iron is too hot, the film may melt and holes may be formed.
This aeroplane is highly pre-fabricated and can be built in a very short time.
However, the work which you have to carry out is important and must be done
carefully. The model will only be strong and fly well if you complete your tasks
competently - so please work slowly and accurately.
When self-tapping screws have to be screwed into wood, apply a little white
glue to prevent them shaking loose: just squirt white glue into the hole before
fitting the screw.
Additional accessories required
Power plant and accessories
Engine
Order No.
Propeller
Order No.
Silencer
Order No.
OS MAX 46 AX
7.45 cc
2701
28 x 15 cm
1318.28.15
1809.33
or
1871.72
OS MAX 46 LA
7.64 cc
1888
28 x 15 cm
1318.28.15
1885.33
or
1870.72
Electric motor and accessories
Electric motor
Order No.
Propeller
Order No.
Flight battery
Order No.
Speed controller
Order No.
COMPACT
465 Z
7772
1318.40.25 9733.3 7224
Radio control system
The RC system must feature at least four channels and four servos. The
transmitter should also include a servo reverse facility.
We particularly recommend mx-16 to mc-24 computer systems. The model is
designed for standard-sized servos, e.g. DES585 BB, Order No. 7930.
We recommend the following receiver battery: NH-800 RX, Order No. 7499.4, which
should be maintained carefully before and after each flying session. Please note that

4
batteries of this type do not reach full capacity until they have been charged and
discharged (cycled) several times.
You will need two suppressor filters, Order No. 1040, to connect the aileron servos to
the receiver, and two further extension leads, 100 mm and 180 mm long. For shock
protection the receiver and receiver battery should be packed in soft foam, e.g. foam
rubber, Order No. 1637.
Adhesives
White glue, e.g. UHU coll, Order No. 958.60
Cellulose cement, e.g. UHU hart, Order No. 534.35
Cyano-acrylate (“cyano”), e.g. Order No. 5822
Thread-lock fluid, e.g. Order No. 952
Accessories required for the glow engine version (not included)
Synthetic oil-based fuel, to suit engine
Fuel filter, e.g. Order No. 1650.1
Fuel tubing, e.g. Order No. 1643
Manual fuel pump, e.g. Order No. 1610
Glowplug battery with glow clip, e.g. Order No. 3253
Electric starter, e.g. Order No. 1628
Starter battery, e.g. Order No. 2592
Accessories required for the electric-powered version (see table)
See the main FS catalogue for details of battery chargers
Tools required (not included)
Set of cross-point screwdrivers, flat-nose pliers, side-cutters, balsa knife or razor
blade, set of twist drills, universal glowplug spanner, soldering iron.
Please don’t start assembling the model until you have checked the kit components
and the building instructions, and are familiar with the construction procedure. If you
are not happy with any component, kindly return it to your model shop without delay.

5
Assembling the TAXI SPORT II
The wing panels
Use your fingertips to locate the opening in one wing for the aileron servo, and
remove the film over it using the tip of a hot soldering iron or a sharp balsa knife.
Press the rubber grommets into the servo mounting lugs, followed by the brass
tubular spacers, with the flange on the underside. The spacers are easier to fit if you
slip them onto a suitable screwdriver first.
Connect the appropriate extension cable to the servo lead, and fit a heat-shrink
sleeve or adhesive tape round the connectors to prevent them working loose.
Route the servo lead through the wing from the servo recess. Fit the servo in the
opening as shown in the photo, drill 1.5 mm Ø pilot-holes for the retaining screws,
and secure it using the screws supplied in the servo accessory pack.

6
Cut down the servo output lever as shown in the photo below.
Fit the output arm on the servo output shaft, facing outward, i.e. towards the wingtip.
This arrangement means that the servos do not need to be reversed; this may be
useful if you are using a “simple” (non-computer) RC system.
Place a setsquare on the wing as shown in the photo, and mark the position of the
servo output arm linkage hole on the aileron, at right-angles to the control surface.
Mark the position of the horn holes on the aileron, and drill 2 mm Ø holes at the
marked points.

7
Fix the horn to the aileron using the pan-head screws and plastic spreader plate
supplied. Tighten the screws just to the point where the horn cannot shift - take care
not to over-tighten them.
Snip off excess screw length using side-cutters before filing back the cut ends flush
with the spreader plate.
Locate the M2 threaded pushrod (180 mm long) and fit a locknut and clevis on the
threaded end. Connect the clevis to the second hole from the outside of the aileron
horn. Use a felt-tip pen to mark the point where the pushrod crosses the linkage hole
in the servo output arm.

8
Use flat-nose pliers to bend the pushrod at right-angles at the marked point, and cut
off excess pushrod material using side-cutters, leaving the bent end around 7 mm
long. Connect the pushrod to the servo output arm and push the plastic keeper into
place to secure it. Repeat the whole procedure with the second aileron servo.
Installing the fin and tailplane
The covering film over the slots for the fin and tailplane should be removed using the
tip of a hot soldering iron. Please note that the iron should be a low-wattage type; the
heat should be just enough to melt the film.
Locate the slots with your fingertips, and mark their outlines with a felt-tip pen. Pierce
the film with the tip of the hot bit, and run it all round the edge of the opening until the
piece of film can be removed.
Repeat the procedure in order to open up the slots for the rudder and elevator
pushrods. Please note: two pushrods are used to actuate the elevators!
Fit the tailplane and fin in their respective slots. Position the tailplane in such a way
that it is at right-angles to the fuselage centreline when viewed from above, and
projects an equal distance on both sides, as shown in the diagram below.

9
Now use a felt-tip pen to mark the outline of the fuselage on the tail panels.
Melt the film by running a hot soldering iron just inside the marked lines, and peel
away the excess film from the joint areas.
The prepared tailplane and fin can now be glued to the fuselage, using either UHU
coll (white glue) or UHU hart (cellulose cement). Position the panels exactly as
described above, align them carefully, and tape them in place. Note that the fin must
be at right-angles to the tailplane.
Allow the glued joints to set hard before installing the steerable tailwheel unit: note
that the tailwheel pivot axis should line up accurately with the rudder hinge axis. Mark
the position of the screw-holes on the underside of the fuselage, and drill 1.5 mm Ø
pilot-holes for the retaining screws.

10
Fix the tailwheel unit to the fuselage using the two retaining screws provided.
The driver lug can now be attached to the bottom of the rudder, so that movement of
the rudder is transferred to the tailwheel. Fit the plastic lug on the projecting wire, and
fix it to the rudder using a single pan-head screw.
Use a pair of side-cutters to snip off the excess length of the driver wire at a point
about 2 mm aft of the plastic lug.

11
Installing the rudder and elevator horns
Screw an M2 locknut and a clevis onto the threaded end of each rudder and elevator
pushrod. Slip the pushrods into the plastic guide tubes and connect the clevises to
the horns.
The horns should be positioned on the control surfaces in such a way that the clevis
linkage hole lines up exactly with the hinge pivot axis. Drill holes for the retaining
screws in the control surfaces.
Note that the rudder horn has to be modified to the shape shown in the photo below.
With the horns in place, file the projecting screw ends flush with the spreader plate.
The rudder and elevator servos must now be centred accurately: connect the
receiving system, switch the transmitter on and check that the associated trims are at
centre.
Install the servos in the servo plate, positioned in such a way that the pushrods
coincide exactly with the linkage holes in the servo output arms. Drill 1.5 mm Ø pilot-
holes for the servo retaining screws, then fix the servos in this position using the
screws supplied in the accessory packs.

12
Mount the swivel pushrod connector in the outer hole of the throttle servo output arm
as shown in the photo. Note that the retaining screw should be tightened just to the
point where the barrel rotates smoothly, but without any slop.
Set the servos to centre, tape the tail control surfaces at neutral, then mark the point
on the pushrods where they cross the linkage holes in the servo output arms.
Link the two elevator pushrods using the Duo pushrod connector before connecting
the unit to the elevator servo using a short pushrod attached to the central hole.
As described for the aileron servos, bend the pushrods at right-angles at the marked
point, cut off excess pushrod material, and connect them to the servo output arms.
Attaching the undercarriage
The first step here is to drill holes in the wheel spats for the wheel axles. Extend the
holes on the inside faces to form open-ended slots, as this makes it easier to install
the spats. Attach the wheels to the undercarriage legs as shown below. Each
requires a wheel axle, two collets and two nuts, which must be secured with a drop of
UHU thread-lock fluid.

13
The photographs above clarify the method of fitting the wheels: on the left the wheel
spat and a cross-section through the wheel, on the right the system minus the wheel.
Once the wheels and spats are fitted, the undercarriage legs can be attached to the
fuselage using the retaining screws provided. Apply a drop of UHU thread-lock fluid
to all the screws to prevent them working loose.
Installing the glowplug engine and silencer
This section describes the installation of the OS MAX 46 AX only.
Place the engine on the mount with both mounting lugs seated squarely on the
mount arms. The distance between the firewall and the front face of the propeller
driver should be 113 mm. You can now mark the position of the holes for the engine
mount on the firewall.
Drill 2 mm Ø pilot-holes for the engine retaining screws (2.4 mm Ø pan-head self-
tappers). Connect the throttle pushrod to the carburettor arm and slip it into the
plastic guide tube. Now fix the engine to the mount from above using the screws
mentioned earlier. Connect the Z-bend of the throttle pushrod to the outermost hole
in the carburettor throttle arm. Slip the plastic guide tube onto the throttle pushrod,
then fit the pushrod through the hole in the firewall, slipping the plain end of the rod
through the cross-hole in the swivel pushrod connector.

14
The engine / mount assembly can now be attached to the firewall using the M4 x 25
machine screws supplied in the kit. These screws must be secured with a drop of
UHU thread-lock fluid to prevent them working loose.
At this point the silencer can be mounted on the engine using the screws supplied.
Assembling and installing the fueltank
Cut a piece of fuel tubing and push it onto the fueltank clunk pick-up. Push the free
end of the fuel tubing onto the straight tube in the fueltank stopper, and check that
the pick-up will be able to move freely inside the tank without binding or jamming
when the stopper is in place. Push the tank stopper, complete with pick-up and pre-
formed tubes, into the throat of the fueltank. Note that one tube must face down (for
filling the tank). The tube pointing up acts as the overflow when refuelling, and is
connected to the pressure nipple on the silencer prior to flying. Mark the three fuel
lines which exit the tank stopper (fuel feed, filler tube, pressure line). Push the
stopper into and over the throat of the tank and tighten the cross-point screw to
clamp it in place. It is essential to tighten the screw to the point where the tank is
completely sealed.
The fueltank can now be installed in the tank compartment immediately aft of the
firewall. Pack foam rubber round it to absorb vibration and prevent it shifting in flight.

15
Push the prepared fueltank into the fuselage and thread the fuel lines through the
hole in the firewall. Glue the tank support behind the fueltank to hold it in place.
Connecting the fuel lines
Connect the silicone fuel line running from the clunk pick-up to the carburettor fuel
nipple, and the tube from the overflow to the pressure nipple on the silencer.
The fuel tube marked as the filler should be routed out of the cowl so that the tank
can be filled through it. Seal the tube before each flight using a sealing nipple, Order
No. 140.
Please note that fuel will run out of the overflow (pressure) line when the tank is full.
Take care not to fill the silencer with fuel.
The cowl can now be fitted, along with the propeller and the spinner. It is important to
check at regular intervals that the propeller retaining screw or nut is still tight.
The next step is to cut or file out openings in the cowl to clear the cylinder head, the
silencer and the needle valve; the position and extent of the openings vary according
to the engine you are using. Note that the needle valve must be extended with a
scrap piece of pushrod material, so that you can still adjust it with the cowl in place.
Attach the cowl to the fuselage using four pan-head self-tapping screws, as shown in
the photos.

16
Installing the switch in the fuselage
The ON / OFF switch for the receiving system can be installed below the hatch on
either side of the fuselage. Cut and file out an opening at the appropriate point to suit
the switch toggle or slider you wish to use. Secure the switch unit in the fuselage side
using the retaining screws supplied with it.
Installing the electric motor
Mark the position of the fixing screw holes on the firewall to suit the motor mount you
intend to use, and drill holes in the firewall at the marked points to suit the retaining
screws.
The electric motor is mounted on stand-off pillars which are cut from the length of
aluminium tube supplied in the kit. Cut four equal lengths of tube to suit your selected
motor; the length is that required to maintain the correct spacing between firewall and
spinner backplate, which - as with the glow-powered version - is around 113 mm.
Install the electric motor as shown in the photograph.

17
The speed controller is fixed to the right-hand fuselage side using a single cable tie,
as shown in the photo below.
Cut down the fueltank support as shown in the picture to form the rear support for the
flight battery, which prevents the pack sliding aft. Glue the support to the former.
The flight battery is held down by a block of foam glued to the fuselage hatch. The
foam, Order No. 2905.25, is an ideal material for this.
Assembling the TAXI SPORT II
We recommend that you permanently connect a suppressor filter, Order No. 1040, to
receiver sockets 2 and 5, as this makes it easier to connect the aileron servos when
rigging the model. Wrap the receiver battery in foam and secure it in the fuselage in
such a way that it cannot possibly shift. Connect the two aileron servos to the
extension leads, then connect the wing panels using the aluminium joiner tube before
attaching the wing to the fuselage using the four plastic screws supplied in the kit.
Balancing the TAXI SPORT II
Assemble the aircraft completely, and support it on both sides of the fuselage at a
point around 90 mm aft of the wing root leading edge. If the model is balanced
correctly, it will hang level, ideally with the nose inclined slightly down.
If necessary, correct the model’s Centre of Gravity by re-positioning the battery, or by
permanently installing nose or tail ballast.
Before flying the aircraft, set the transmitter trims to centre and ensure that all the
control surfaces are also exactly at centre (neutral).

18
Control surface travels
Ailerons 10 mm up and down )
Elevators 11 mm up and down ) 30% Exponential
Rudder 35 mm right and left )
Please note that the stated control surface travels are just a starting point; you may
well wish to adjust them to suit your personal preference and flying style.
Important:
When fitting and adjusting the various linkages you should ensure that they move
freely, without binding, are able to move to their full extent - including trim travel - and
are not obstructed mechanically at any point.
When you move the rudder stick to the right, the rudder should also deflect to the
right (left stick: left rudder). Pull the elevator stick back towards you, and both
elevators must deflect up (stick forward: elevators down). If you move the aileron
stick to the right, the right aileron should rise, the left aileron fall. When you move the
throttle stick forward, the motor should run at full power; pull the throttle stick back for
idle. Move the throttle trim right back to its end-point, and the engine or motor should
stop reliably.
All that remains is to wish you many hours of pleasure flying your TAXI SPORT
II.

19
Safety notes and warnings relating to model aircraft powered by internal-
combustion engines
Be sure to read right through the instructions covering assembly and operation
of your model before you attempt to operate it for the first time.
These safety notes are an integral part of the instructions. Please keep them
and the operating instructions in a safe place. If you ever dispose of the model
be sure to pass them on to the new owner.
Powered model aircraft are very demanding and potentially dangerous
machines, and call for a high level of technical knowledge and skill from the
operator, together with a responsible attitude.
Powered model aircraft are not suitable for young persons under eighteen
years of age.
Young people should only be permitted to operate this model under the
instruction and supervision of an adult who is aware of the hazards involved in
this activity.
The operator of the model must be in full possession of his or her bodily and
mental faculties. As with car driving, operating a model aircraft under the
influence of alcohol or drugs is not permissible under any circumstances.
Radio-controlled model aircraft may only be employed for the purpose intended
by the manufacturer. They must never be used as man-carrying machines. Any
other use of this model is prohibited.
A radio-controlled model aircraft can only work properly and fulfil your
expectations if it is built very carefully and in accordance with the building
instructions. Do not make any modifications of any kind to the design features
or materials. If you wish to avoid injuring people and damaging property it is
essential to be careful and painstaking at all stages of building and operating
your model. Nobody would climb into a full-size light aircraft and try to fly it
without completing a course of training first. Model flying is a skill which has to
be learned in just the same way. We suggest that you ask for help from an
experienced model flyer, or join a model club or flight training school. Your
local model shop and the model magazines are good sources of information.
It is fundamentally essential to set the Centre of Gravity (C.G.) and control
surface travels correctly. Adjust the model until they are exactly correct.
•Radio control system: satisfy yourself that your frequency is vacant before
you switch on. Check your RC system regularly as its components
eventually wear and need to be replaced or repaired. Radio interference
caused by unknown sources can occur at any time without warning. If this
should happen, your model will be uncontrollable and completely
unpredictable. Never leave your radio control system unguarded, as other
people might pick it up and try to use it. Your RC system can only work
reliably if the batteries are kept fully charged.

20
Don’t ignore our warnings. They refer to materials and situations which, if
ignored, can result in fatal injury or permanent damage.
You alone are responsible for the safe operation of your radio-controlled model
aircraft and engine.
If you have any questions regarding the safe operation of your RC model
aircraft, please turn to your local model shop in the first instance as the staff
will be pleased to help you.
•Propellers and other rotating parts which are powered by an engine
represent a permanent hazard and present a real risk of injury. Don’t touch
them with any part of your body. For example, a propeller spinning at high
speed can easily slice off a finger.
•Keep well clear of the rotational plane of the propeller. You never know
when some part may come loose and fly off at high speed, hitting you or
anybody else in the vicinity. Never touch the revolving propeller with any
object.
•Take care with loose clothing such as scarves, loose shirts etc. Flapping
cloth can easily be sucked into the area of the propeller and then get
tangled in the blades. This is extremely dangerous.
•If there are passers-by or spectators at your flying site, make sure that they
are aware of the dangers inherent in your activity, and insist that they keep
a safe distance away (at least 5 m).
•Radio-controlled models should only be flown in “normal” weather
conditions, i.e. a temperature range of -5° to +35° C. More extreme
temperatures can lead to changes in battery capacity, material
characteristics and other unwanted effects.
•Model fuels are toxic; do not allow them to come into contact with your
eyes or mouth. Fuel should always be stored in clearly marked containers,
out of the reach of children.
•Never run an internal combustion engine in an enclosed space such as a
cellar, garage etc. Model engines produce lethal carbon monoxide gas just
like full-size engines.
Engines should only be run in the open air!
•Adhesives and paints contain solvents which may be hazardous to health
under certain circumstances. Read and observe the notes and warnings
supplied by the manufacturer of these materials.
•Model fuels are volatile and highly inflammable. Keep them well away from
open flames, excessive heat, all possible sources of sparks and anything
else which could result in a fire. Do not smoke in the immediate vicinity of
fuel or fuel vapours.