GRAUPNER Skalar User Manual

GRAUPNER GmbH & Co. KG D-73230 KIRCHHEIM/TECK GERMANY

No liability for modifications, errors and printing errors. ID# 570 57 12/ 06

elektro

Skalar

Model helicopter

Order No. 4475 Kit

Order No. 4476 Mechanics Kit

Warning!

The contents of this kit can be assembled to produce a working RC helicopter, but the
model is by no means a harmless plaything. It is a complex flying machine, and if
assembled incorrectly or handled incompetently or carelessly it can cause serious injury
to persons and damage to property.
You alone are responsible for completing the model correctly and operating it safely. The
kit also includes two further information sheets - SHW 3 and SHW 7 - which include
safety notes. They are an essential part of these instructions.

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Introduction

The elektro Skalar is a high-performance electric helicopter which offers extreme flexibility in
terms of power system and rotor size. The model is designed for use with a brushless out-run­ner motor, a speed regulator (for constant RPM) and LiPo flight batteries with 5 … 10 cells.

In its basic form the model’s rotor diameter is 1365 mm, and power comes from a Compact
555/20V brushless out-runner motor in conjunction with an 8-cell LiPo battery. In this configura­tion the helicopter is capable of flying in a highly dynamic style, including classic aerobatics and
“3-D” manoeuvres, and its performance is entirely the equal of a comparable glow-powered
model. Fitting a 10-cell LiPo pack instead of an 8-cell one provides a substantial increase in the
power reserves required for demanding (“3-D”) flying.
However, it is also possible to operate the model with a (relatively low-cost) 5-cell LiPo battery if
you install a Compact 555/18.5V motor; the result is a smooth-flying model suitable for a less
energetic piloting style.
At the other extreme you have the option of fitting the higher-torque Compact 655/20V motor, in
which case the model can be operated with 8 to 10 LiPo cells and a larger rotor diameter of
around 1500 mm. This system can then be installed in one of the numerous enclosed fuselages
in the Graupner/Heim helicopter system; alternatively it can be fitted with the separately available
tail boom (approx. 80 mm longer) to form an open-style (pod-and-boom) model.

The flight times which can be achieved vary primarily according to the motor, the flight battery,
the selected rotor blades and the mechanical set-up; a typical example would be around 15 min­utes with eight 4.8 Ah cells.

The flight batteries are positioned at the bottom of the helicopter in a strong, lightweight tray
which is housed inside the chassis. The tray is assembled from machine-cut carbon fibre plates;
access is good, and the batteries can easily be replaced.

The tall chassis provides adequate tail rotor ground clearance in conjunction with the curved tail
boom, through which the tail rotor shaft runs in a curve, eliminating the problem of oscillation.
The helicopter’s large tail rotor diameter provides excellent control response around the vertical
(yaw) axis. The tail rotor is actuated by a free-running, slop-free CFRP pushrod, and is driven in
auto-rotation mode.

The lightweight mechanics fairings is moulded in GRP and supplied pre-painted; it is mounted
on rubber grommets to absorb vibration, and can be fitted and removed in moments, providing
excellent and speedy access to the radio control components and mechanical system.

The long black eloxided tail boom is adequately supported by four braces, and can be replaced
in a matter of minutes if damaged; its length is designed to allow the use of a range of rotor
blades, giving possible main rotor diameters of 1160 to 1365 mm.

The elektro Skalar mechanics kit, Order No. 4476, is designed to be installed in any suitable
fuselage in the Graupner/Heim system. It contains the main chassis including main rotor head,
plus tail rotor and tail rotor gearbox, but excludes the tail boom, skid landing gear, main rotor
blades and cabin.

Specification

Length excl. rotor approx. 1310 mm
Width excl. rotor approx. 240 mm
Height approx. 430 mm
Rotor Ø range 1160...1365 mm
All-up weight min. approx. 4000 g

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Warning notes

• The contents of this kit can be assembled to produce a working helicopter, but the

model is by no means a harmless plaything. If assembled incorrectly or handled

incompetently or carelessly it can cause serious injury to persons and damage to

property.

• When the model helicopter’s motor is running, the two rotors are spinning at high

speed and contain an enormous quantity of rotational energy. Anything and

everything that gets into the rotational plane of the rotors is either damaged or

destroyed - and that includes parts of your body. Please take extreme care at all times

with this machine.

• If any object obstructs the rotational plane of the revolving rotors the rotor blades will

probably be severely damaged as well as the object. Broken parts may fly off and

result in enormous imbalance; the whole helicopter then falls into sympathetic

vibration, you lose control and have no way of predicting what the model will do next.

• You may also lose control if a problem arises in the radio control system, perhaps as a

result of outside interference, component failure or flat or faulty batteries, but in any

case the result is the same: the model helicopter’s response is entirely unpredictable.

Without prior warning it may move off in any direction.

• Helicopters have many parts which are naturally subject to wear, including gearbox

components, motor, ball-links etc., and this means that it is absolutely essential to

check and maintain the model regularly. It is standard practice with full-size aircraft to

give the machine a thorough „pre-flight check" before every flight, and this is equally

important with your model helicopter. Constant checking gives you the opportunity to

detect and correct any faults which may develop before they are serious enough to

cause a crash.

• The kit also includes two further information sheets - SHW 3 and SHW 7 - which

include safety notes and warnings. Please be sure to read them and keep to our

recommendations. They are an essential part of these instructions.

• This helicopter is designed to be constructed and operated by adults, although young

people of 16 years or older may do so under the instruction and supervision of

competent adults.

• The model features sharp points and edges which may cause injury.

• Flying model aircraft is subject to certain legal restrictions, and these must be

observed at all times. For example, you must take out third party insurance, you must

obtain permission to use the flying site, and you may have to obtain a licence to use

your radio control system (varies from country to country).

• It is important to transport your model helicopter (e.g. to the flying site) in such a way

that there is no danger of damaging the machine. Particularly vulnerable areas are the

rotor head linkages and the tail rotor generally.

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• Controlling a model helicopter successfully is not easy; you will need persistence and

determination to learn the skills, and good hand-eye co-ordination is a pre-condition.

• Before you attempt to fly the model it is absolutely essential that you should study the

subject of helicopters in depth, so that you have a basic understanding of how the

machines work. Read everything you can on the theory of helicopters, and spend as

much time as you can watching other model helicopter pilots flying. Talk to chopper

pilots, ask their advice, and enrol at a specialist model flying school if you need to.

Many model shops will also be prepared to help you.

• Please be sure to read right through these instructions before you start work on the

model. It is important that you clearly understand each individual stage of assembly

and the correct sequence of operations before you begin construction.

• Don’t make modifications to the model’s construction by using parts other than those

specifically recommended, unless you are certain of the quality and suitability of the

substitute parts for the task.

• We have made every effort to point out to you the dangers inherent in operating this

model helicopter. Since neither we, the manufacturer, nor the model shop that sold

you the kit have any influence on the way you build and operate your model, we are

obliged to disclaim any liability in connection with it.

Liability exclusion / Compensation

As manufacturers, we at GRAUPNER are not in a position to influence the way you build

and set up the model, nor install, operate and maintain the radio control system

components. For this reason we are obliged to deny all liability for loss, damage or costs

which are incurred due to the incompetent or incorrect use and operation of our

products, or which are connected with such operation in any way.

Unless otherwise prescribed by binding law, the obligation of the GRAUPNER company

to pay compensation, regardless of the legal argument employed, is limited to the invoice

value of that quantity of GRAUPNER products which was immediately and directly

involved in the event which caused the damage. This does not apply if GRAUPNER is

found to be subject to unlimited liability according to binding legal regulation on account

of deliberate or gross negligence.

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Contents

• Foreword ............…............................ P.2

• Warning notes ..................................... P.3

• Accessories, additional items required ................... P.6

• 1. Assembling the main mechanics ..................... P.7

• 2. Installing the radio control system ..................... P.19

• 3. Assembling the main rotor head ...................... P.21

• 4. Assembling the tail rotor gearbox ..................... P.26

• 5. Installing the control bridge .......................... P.28

• 6. Assembling the tail rotor head ........................ P.29

• 7. Tail boom ...................................... P.30

• 8. Installing the skid landing gear ........................ P.33

• 9. Tail rotor control system ............................ P.34

• 10. Cabin ......................................... P.35

• 11. Main rotor blades ................................ P.36

• 12. Setting up ..................................... P.37

• 13. Final checks before the first flight .................... P.39

• 14. Maintenance .................................... P.39

• 15. Adjustments during the first flight, blade tracking .......... P.40

• 16. General safety measures .......................... P.41

• 17. Basic helicopter terminology ........................ P.42

The instructions

We have invested considerable effort in producing these instructions, with the aim of ensuring
that your model helicopter will fly reliably and safely. Please take the trouble to follow the
instructions step by step, exactly as described, as this guarantees a successful outcome. This
applies to you whether you are a relative beginner or an experienced expert.

• The illustrations show how the model is constructed; be sure to read the instructions which
accompany the drawings.

• All the joints marked with this symbol need to be secured with thread-lock fluid,
e.g. Order No. 952, or bearing retainer fluid, Order No. 951. Remove all traces of grease
from the joint surfaces before applying the fluid.

• All bearings, whether plain, ballrace or needle roller, must be lubricated thoroughly. The
same applies to all ball-links and gears, even if the instructions do not state this specifically.

• You will find the parts list, replacement parts list and the associated exploded drawings at the
end of these instructions.

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Accessories

Recommended motors and accessories for the elektro Skalar

Motor Speed controller Batteries
COMPACT 555 18,5V
Order No. 7726

COMPACT CONTROL 80
HELI

Order No. 7187
or

COMPACT CONTROL 75S
HELI
Order No. 7207

1 Pcs. LiPo 5/3400, Order No.7648.5 or LiPo 5/4800, Order No.7658.5
or
2 Pcs. LiPo 3/3400, Order No.7648.3 or LiPo 3/4800, Order No. 7658.3
or
1 Pcs. LiPo 5/3400, Order No.7648.5 or LiPo 5/4800, Order No. 7658.5
and
1 Pcs. LiPo 2/3400, Order No.7648.2 or LiPo 2/4800, Order No. 7658.2

COMPACT 555 20V
Order No. 7716

COMPACT CONTROL 80
HELI

Order No. 7187
or

COMPACT CONTROL 75S
HELI
Order No. 7207

2 Pcs. LiPo 4/3400, Order No.7648.4 or LiPo 4/4800, Order No. 7658.4
or
2 Pcs. LiPo 5/3400, Order No.7648.5 or LiPo 5/4800, Order No. 7658.5
or
1 Pcs. LiPo 5/3400, Order No.7648.5 or LiPo 5/4800, Order No. 7658.5
and
1 Pcs. LiPo 4/3400, Order No.7648.4 or LiPo 4/4800, Order No. 7658.4

COMPACT 655 20V
Order No. 7726

COMPACT CONTROL 80
HELI

Order No. 7187
or

COMPACT CONTROL 75S
HELI
Order No. 7207

2 Pcs. LiPo 5/3400, Order No.7648.5 or LiPo 5/4800, Order No. 7658.5

Attention: Be sure to combine only battery packs with equal capacity (3400mAh or 4800mAh)!

Suitable main rotor blades

Order No. 1296 GRP, reflex-section, 552 mm long Rotor Ø 1261 mm
Order No. 1269 GRP, symmetrical, 552 mm long Rotor Ø 1261 mm
Order No. 1271 GRP, symmetrical, 602 mm long Rotor Ø 1361 mm (supplied)

Radio control equipment: see main Graupner catalogue

We recommend using a radio control system equipped with special helicopter options, or a
micro-computer radio control system such as the mx-16s, mc-19, mx/mc-22 or mx/mc-24.

As a minimum the radio control system must feature a 3-point swashplate mixer and five
directly connected servos for the functions pitch-axis, roll, collective pitch, tail rotor and
motor.

Servos: the model should only be flown with high-performance servos, e.g. C 4041, Order No.

3916, or servos of at least comparable performance.

Gyro system:
SRVS Gyro-System G490T, Order No. 5137 or
SRVS Gyro-System G770T, Order No. 5959 or
SRVS Gyro-System G7000T, Order No. 5956 or
SRVS Gyro-System G8000T, Order No. 5957

with
Super-Servo DS-8700G, Order No. 5156 or
Super-Servo DS-8900G, Order No. 5182 or
Super-Servo DS-8100G, Order No. 5153

Receiver power supply:

For safety reasons it is essential to use a pack of at least 1000 mAh capacity, together with a
switch harness with adequate cable cross-section for the high currents which will flow.

Do not use a receiver battery with more than 4 cells under any circumstances.

We also recommend a voltage monitor module, Order No. 3138, which allows you to monitor the
voltage of the receiver battery constantly.

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1. Assembling the main mechanics

The mechanics consist largely of glass fibre reinforced nylon, a material which offers consider­able advantages for model helicopter construction compared with, say, aluminium. These ad­vantages include high mass constancy combined with low weight, freedom from fatigue effects,
low noise when operating, and the ability to absorb motor vibration. The design of this type of
mechanical system endows it with great robustness and rigidity; in a hard landing it is preferable
that the parts should either survive undamaged (and therefore be unconditionally re-usable) or
simply break, in which case they have to be replaced. In contrast, if the chassis should bend or
warp, such damage might not even be noticed, but it would certainly have a serious adverse ef­fect on the other components, which might not work at all, might fail prematurely, or could even
jeopardise the safety of the whole system. These are problems inherent to metal mechanical
systems, but they do not occur with our type of construction.
The many advantages of reinforced nylon construction are balanced by just a few drawbacks:
the parts are more complex (and therefore more expensive) to manufacture, and the builder is
required to be more careful and conscientious when assembling and setting up the components;
slight trimming of the parts themselves may also be necessary occasionally. The reward for a
considered, patient approach is a model which is very durable, wears very slowly, and therefore
has an extended useful life.

Shafts, bearings and fits
Virtually all the rotating parts of the mechanics are ballraced. When ballraces are used it is very
important that the shaft is a tight fit in the inner ring of the race, so that it cannot revolve within
the ring. Otherwise the inner ring heats up (discolouring it blue or yellow), damaging the bearing
and rendering it unusable. In the worst case the bearing may become so hot that it melts the
nylon seating, and the shaft then loses its position relative to other components. Please note that
this is not a fault in the bearing seat material; it is simply a result of incorrect bearing fits.
A further possible result of a loose bearing fit is that the shaft slips within the inner ring, and its
diameter is worn down in the bearing area. In this case the carefully set meshing clearance of
any gears mounted on the shaft is lost, i.e. the gears no longer mesh correctly, leading to in­creased rates of wear and eventual failure.
In the Graupner/Heim system the fits between shafts and ballraces are maintained on the tight
side, in order to avoid the problems described above. However, manufacturing tolerances are
inevitable, and occasionally the result is too tight a fit, i.e. the bearing cannot be pushed onto the
shaft. In this case the shaft must be rubbed down using fine abrasive paper (600 - 1200 grit) un­til the bearing can be pushed onto it using no more than moderate force.
If the fit should be loose - which can also arise with the accumulation of manufacturing toler­ances in both parts - the bearing can simply be glued to the shaft using LOCTITE bearing re­tainer fluid 603, which guarantees a firm seating. Please note that the cure time for bearing re­tainer fluid varies with the fit: the tighter the joint, the quicker it cures. Under certain circum­stances you may only have a few seconds to locate the bearing correctly on the shaft before it is
permanently and immovably fixed.
If a shaft is supported in multiple ballraces, it is important to prevent the bearings being under
tension in the axial direction. This can be achieved in either of two ways: either by locating both
bearings on the shaft very accurately, or by using a combination of fixed and sliding fits: one ball­race is a press-fit on the shaft, or glued in place, making it immovable, whereas the other bear­ing is a sliding fit, i.e. it can be moved along the shaft axially using moderate force. It will then
take up its optimum position automatically when installed.
In general terms you can assume that the smaller the shaft diameter and the higher the rota­tional speed, the higher the danger of wear in bearings.
The smaller the difference between inside diameter and outside diameter of the ballraces, the
higher the danger of tension in the bearings against each other.
If your model is to be as safe and reliable as it possibly can be, then all this needs to be taken
into account whenever you are fitting a ballrace to the model. For this reason the building in­structions always state when thread-lock fluid or bearing retainer fluid must be used for the vari­ous joints and connections.

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1.1 Assembling the tail rotor drive unit

(bag UM-1A

)

The shaft of the quick-release coupling 4618.57 must not exhibit any axial play in the bearings

4618.6. If the shaft is not a tight enough fit in the bearings, glue it in the ballraces using bearing
retainer fluid 603, Order No. 951. This is the procedure: start by applying bearing retainer fluid
603 to the rear ballrace and slide it along the shaft until it rests against the coupling yoke. Wait
until the adhesive has cured, which may take anything between 20 seconds and 30 minutes
depending on the fit. Press this assembly fully (as far as it will go) into the bearing holder

4448.14, then apply bearing retainer fluid 603 to the front ballrace and push it straight onto the
shaft and into the bearing holder as far as it will go. Now - before the adhesive cures - immedi­ately check that the shaft still rotates freely, as it is possible that axial tension will make the
bearings stiff to move. If this happens, tap lightly on the end of the shaft with a screwdriver
handle or similar, or tap harder on the bearing holder until the races rotate freely. When you are
satisfied, leave the bearing retainer fluid to cure fully.
Now fit a shim washer and the pinion 4450.41 on the front end of the shaft, press them against
the front bearing and tighten the two grubscrews in this position. This is the procedure: first apply
a drop of thread-lock fluid (Order No. 952) to the threaded holes, and fit the first grubscrew so
that it engages fully on the flat ground into the shaft; rotate the pinion to and fro until the
grubscrew engages fully, then tighten it moderately. Now fit the opposite grubscrew and tighten it
very firmly, before finally tightening the first grubscrew permanently. This procedure ensures that
the pinion rotates absolutely true.

1.2 Assembling the layshaft

(bag SKA-1B)

Fix the bottom bearing 4450.31 to the layshaft 4450.7 using bearing retainer fluid 603, Order No.
951; the ballrace should rest against the pinion. Allow the adhesive to cure fully, then press the
shaft and bearing into the bottom bearing support 4448.11B. Fix the upper bearing 4450.31 to
the upper bearing support 4475.11 using bearing retainer fluid 603, Order No. 951 and allow the
adhesive to cure fully.

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Slip the top bearing support 4475.11 on the shaft, leaving it loose initially (note correct orien­tation; the opening in this bearing support must face up), then fit a shim washer followed by the
gear 4618.105, with the freewheel sleeve 4618.107 inserted. Line up the cross-holes in the shaft
and freewheel sleeve, and carefully press the roll-pin 4618.65 through the parts, but only to the
point where it engages in the shaft; this enables you to withdraw it again if necessary.

Now slide the bearing support 4475.11 with the glued-in ballrace up against the shim washer
under the freewheel sleeve; the bearing must be able to be moved along the shaft axially using
moderate force but without beeing loose (sliding fit). Temporarily fit the layshaft assembly bet­ween the mechanics side frames 4450.9 and 4450.10, and check that the top bearing rests
against the shim washer and the freewheel sleeve when installed; if there is a gap, this must be
corrected by fitting additional shim washers. Don’t fit too many shim washers, as this would
place the bearings under excessive strain!

Once the clearance is correct, press the roll-pin completely into the freewheel sleeve. This
assembly must now be screwed between the mechanics side frames so that you can check that
the bearings are free-moving; if not, tap lightly on the ends of the shaft, as already described.

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1.3 Preparing the main rotor shaft and bearings

(bag UM-1C)

Fix the swashplate guide 4618.113 to the dome bearing holder 4448.8 using two M2 x 12
cheesehead screws. Press a ballrace 4450.24 into the dome bearing holder and another into the
main rotor shaft bearing holder 4448.12 (grease the bearings).

Slide the circlip 4607.156 onto the main rotor shaft 4450.43 from the top end, and allow it to
snap into the channel; please note the following:

• The circlip must not be over-stretched, i.e. don’t open it further than is absolutely necessary
to fit it on the main rotor shaft; use special circlip pliers if possible.

• The inner face of the circlip features one rounded and one sharp edge; the sharp edge must
face up.

• The circlip must be a firm fit on the shaft; it should not be possible to rotate it by hand.

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1.4 Assembling the main gearbox

(bag SKA-1)

Fix the tail rotor drive unit, the layshaft and the main rotor shaft bearing holders between the
mechanics side frames 44750.9 and 44750.10 using M3 x 16 socket-head cap screws, but don’t
tighten the screws fully at this stage. Fit a shim washer 4450.40 and the dome bearing holder
onto the main rotor shaft from the underside. Working from above, pass the main rotor shaft
through the bottom rotor shaft bearing and the ring gear 4450.20A to the point where the dowel
pin 4450.37 can be fitted through the cross-hole at the bottom end of the main rotor shaft. Now
pull the main rotor shaft up fully, so that the dowel pin engages in the recess in the ring gear. Fix
the dome bearing holder between the mechanics side frames using M3 x 16 socket-head cap
screws, and check for axial play between the main rotor shaft and the bearings; there should be
none at all. If necessary fit additional shim washers under the circlip to remove any lost motion.
However, take care not to place the ballraces under strain by fitting too many and/or too thick
washers.

To add or remove the shim washers always undo the dome bearing and remove the main
rotor shaft in the opposite sequence to that described for installation. On no account re­move the circlip from the main rotor shaft!

The next step is to set the correct meshing clearance in the gearbox. Initially the meshing clea­rance of this gearbox stage should be set too tight, so that the gears roll „hard“ against each
other. If this is not possible, i.e. if there is already detectable gear clearance at the tightest set­ting when the mechanics are screwed together, the bottom main rotor shaft bearing 4448.12
must be removed, turned through 180°, and re-installed. If this is still not sufficient, turn the

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bottom layshaft bearing bracket through 180° horizontally and re-install it. This procedure com­pensates for any slight offset of the brass inserts in the bearing supports; these manufacturing
tolerances can never be completely avoided. The meshing clearance between the spur gear and
the layshaft pinion can now be adjusted by loosening the M3 x 16 socket-head cap screws
slightly in the bearing brackets, drawing a strip of thick writing paper between the gears, pres­sing the gears together, and re-tightening the screws. Wind the paper out, and the gears should
now rotate smoothly without any tendency to bind at any point; if you are not sure, repeat the
adjustment process.

1.5 Installing the motor

(bag SKA-2)

Screw your selected motor to the motor mount 4475.05 as shown in the illustration. Place this
assembly in the mechanics, and position it so that the rear of the motor mount can be attached
to the underside of the upper layshaft bearing bracket using M3 x 12 socket-head cap screws.
You will find two holes in the lower layshaft bearing bracket, through which the allen key can be
fitted in order to tighten the screws. The upper bearing bracket features three pairs of threaded
holes which, in conjunction with the slots in the motor mount, make it possible to attach the mo­tor mount in a position to suit the various motor pinions which can be used. You may need to
turn the bearing bracket through 180° horizontally to obtain the correct position of the appropri­ate pair of threaded holes.
At the front the motor mount should be fixed to the motor mount holder 4475.27 using two M3 x
10 socket-head cap screws, at the same time fitting an appropriate number of plastic spacer
washers (type “C” from the laser-cut washer set) between the parts to suit the motor pinion you
are using. The slots in the motor mount allow adjustment of the meshing clearance in the first
gearbox stage. This is carried out by first feeding a strip of thick drawing paper between the
gears, then pressing the gears together before tightening the motor mount retaining screws fully.
Ensure that the gears rotate exactly parallel to each other, i.e. that the motor is not installed at
the wrong angle. Remove the paper strip from between the gears, and you should just be able to
detect minimal gear meshing clearance.

Note: if you find that you cannot mount your chosen motor correctly because it fouls the me­chanics side frames, remove material from the frames using a fretsaw and file.

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1.6 Assembling the sub-structure

(bag SKA-4)

The laser-cut spacer washer set contains three different types:
A = two 2.2 mm holes; B = one 2.2 mm hole; C = one 3 mm hole

First assemble the three CFRP plates to form the battery tray 4475.100, set the parts exactly at
right-angles, and glue them together using cyano. Attach the spacer washers as shown in the
drawing.

Glue the spacer washers to both sides of the upper partial frame 4475.101 using cyano, in the
positions shown in the drawing.

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The bracket for the receiving system switch is designed to be attached to the right-hand side of
the upper partial frame 4475.101, as shown in the drawing.

(*) Alternatively the switch plate can be turned through 90° as shown, and installed without the
tubular spacers. This may be advantageous if you intend installing the mechanical system in an
enclosed fuselage.

Assemble the sub-structure from the following components as shown in the drawings: side
frames 4448.34, bulkhead 4450.18, battery holder 4475.100, upper partial frame 4475.101,
spacers 4450.17, RC box 4448.101 and skid brackets 1291.21A, using the sizes of self-tapping
screw stated in the drawings.

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1.7 Attaching the mechanics to the sub-structure

Offer up the circular spigots on the main gearbox (from Stage 1.5) to the sub-structure side
frames at the rear, and allow them to snap into place. Fix the parts together using M3 x 16
socket-head cap screws and washers.

Two further M3 x 16 socket-head cap screws are used in the centre; fit a washer on each one
first. Fit the brass sleeves 4450.34A in the sub-structure side frames, and fit the screws through
them and the upper part-frames with the on-glued spacers into the mechanics side frames.
Tighten the screws in this position.
Undo the two M3 x 16 socket-head cap screws at top front which were fitted into the spacer

4475.27 when the motor was installed, then fit the upper part-frames 4475.101 and the spacer

sleeves 4450.34A and tighten the screws fully again. Fix the rear end of the partial chassis hal­ves to the lower attachment points of the front (unused) servo aperture in the mechanics side
frames, in each case using two 2.2 x 13 mm self-tapping screws.

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1.8 Power supply to the drive motor

The two flight batteries are wired in series to produce a sum of the two voltages. The diagram
shows the basic wiring of the batteries, speed controller and drive motor; the exact procedure is
described in the instructions supplied with the speed controller and drive motor.

1.9 Installing the flight batteries

The flight packs are housed in the battery tray inside the mechanics sub-structure, and retained
using Velcro (hook-and-loop) tape. You can set the correct Centre of Gravity by adjusting the
fore-and-aft position of the batteries; they should then be secured permanently using Velcro ca­ble ties.

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1.10 Collective pitch compensator and swashplate

(bag UM-8)

The collective pitch compensator 4618.47A is assembled as shown in the drawing.

The first step is to fit a circlip on each of the brass pins and glue them in the holes in the collec­tive pitch compensator hub 4618.46 using bearing retainer fluid, with the circlips resting in the
recesses. Remove any rough edges from the collective pitch compensator arms and fit them on
the projecting end of the pins, fitting at least one shim washer between hub and arm; the arms
must rotate freely on the pins; if not, de-burr the holes. When you fit the outer circlips there
should be no axial play in the arms on the pivot pins; if there is, fit additional shim washers to
take up the slack.

Make up three pushrods as shown in the drawing, using three threaded rods 1291.10 (2,5 mm
Ø, 75 mm long) and six ball-links 4618.155; the stated dimension refers to the free length bet­ween the ball-links.

One pushrod should be attached to the rear point of the swashplate linkage; fit it over the guide
spigot on the swashplate 4682.45 and press it onto the linkage ball located at its base, then fit
the brass sleeve (from 4618.113) on the guide spigot and grease it well. Slide the swashplate
onto the main rotor shaft, slipping the pushrod (already connected) down through the opening in
the rear of the dome bearing holder; you will need to flex the swashplate guide 4618.113 back
carefully to allow the brass sleeve on the swashplate spigot to engage in the guide channel.
Fit the collective pitch compensator on the main rotor shaft, and press the two ball-links onto the
linkage balls on the swashplate inner ring; the balls concerned are indicated in the drawing.

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2. Installing the radio control system

(bag SKA-9)

2.1 Fitting the servos

Fix brass balls to the inside of the output arms on the pitch-axis servo (1) and the roll servos (2)
+ (3) using M2 x 10 cheesehead screws and M2 nuts, with the nuts on the outside. Apply a drop
of thread-lock fluid between screw and ball and also to the nut. The distance (lever length) from
ball centre to servo shaft centre should be about 18 mm. Install the pitch-axis servo first: fit it in
the servo aperture in the right-hand side frame from the inside, with the output shaft at the top,
and secure it with four screws, rubber grommets and metal spacer sleeves (all parts supplied
with the servo): the tubular spacers must be fitted into the underside of the grommets, the
screws fitted from above.

The servo mounting holes in the mechanics are deliberately offset slightly towards the outside,
so that the rubber grommets are under slight tension when the servo is installed; this helps to
produce even more precise control.

Fit the roll servos into the right and left side frames from the outside (see drawing; output shafts
at the top again), and secure them with four screws each. Connect the servos to the receiver in
the sequence described in the radio control system instructions. Switch on the RC system and
activate the swashplate mixer in the transmitter (setting: symmetrical three-point linkage, two roll
servos, 1 pitch servo at the rear). Set the collective pitch, pitch-axis and roll controls and trims to
neutral, and fit the servo output arms on the servos at right-angles to the rotor shaft. Fit the
servo output arm retaining screws.

Install the tail rotor servo in the left-hand side frame from the outside, with its output shaft at the
top, and screw it in place. The tail rotor servo output arm must face down, and should be parallel
to the main rotor shaft when the transmitter control for collective pitch is set to centre.
Run the servo leads through the vacant front servo aperture in the right-hand side frame, bundle
them together and wrap them in spiral tubing. Run the leads forward to the receiver along the
right-hand side of the mechanics. Take particular care to deploy the servo leads neatly and
safely. No cable should be allowed to touch any shafts or gears (potential crash hazard if a cable
chafes and rubs through).

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Connect the swashplate servos to the swashplate using the previously prepared pushrods to
produce a 120° linkage.

2.2 Installing the remaining radio control system components

To attach the gyro inside the RC box we suggest using double-sided foam tape, e.g. Order No.

742. If you install the gyro in another place, be sure not to run the cables from the gyro to the

receiver close to the motor or the controller. Run the cables forward to the receiver, together
with the servo leads, along the side of the mechanics.

Pack the receiver battery and receiver in foam rubber and stow them in the RC box. Install the
motor controller close to the motor on the lower strut of the leftside upper part frame using
double-sided foam tape and cable ties to secure it.

Wrap the leads with spiral tubing and fix them to the mechanics using cable ties. The cables
must not be under tension or strain, must not be able to touch any moving or rotating parts, and
must not be in danger of chafing on any sharp edges.

The receiving system switch is intended to be mounted in the switch bracket attached to the
right-hand side of the upper partial chassis. Connect it to the receiver and the receiver battery.
If you install the switch console as described, the RC switch will be easily accessible even when
the canopy is in place. If you intend installing the mechanics in a different fuselage, you may
prefer to install the switch console in an alternative position, as already described: swivel it up­wards through 90° around the front attachment point.
The switch plate can now be fixed to the partial chassis without the tubular spacers, since the
switch itself rests within the machined opening in the partial chassis.

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3. Assembling the main rotor head

(bag SKA-10)

Der Hauptrotorkopf wird entsprechend den Abbildungen zusammengesetzt, alle Kugellager sind
zu fetten.

3.1 Preparing the blade holders

First attach the two linkage balls to the mixer levers 4448.132A using M2 x 10 screws, then
press the ballraces into both sides, not forgetting the brass spacer sleeve between them.
Apply a little thread-lock fluid to the M3 x 20 screws along the entire length of the threads, and fit
these through the ballraces and the spacer sleeve; take care that no thread-lock fluid gets into
the bearings. Screw the mixer levers to the blade holders in this way, and check that the brass
spacer washer is fitted between the inner ballrace and the blade pitch arm. The mixer levers
should now rotate freely in their bearings; if necessary lubricate them with silicone oil.

Press the radial ballrace 4607.31 and the bearing shell of the combination bearing 1254.13 into
the blade holders 1252.11 as shown in the drawing, pushing them in as far as they will go.

At this point you should check that the ballraces 4607.31 in the prepared blade holders can be
fitted easily onto the blade pivot shaft 4607.29; you may need to rub down the blade pivot shaft
using fine abrasive paper (600-grit or finer) until the bearings are a sliding fit.

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3.2 Installing the blade holders

Press the two O-rings 4607.28 into both sides of the rotor head centre piece 4682.26, then
grease the blade pivot shaft 4682.29 and slide it through to the point where it projects by an
equal amount on both sides. Check that the O-rings are not pushed out of place when you fit the
pivot shaft.
Now hold this assembly with the blade pivot shaft standing vertical. Fit a 0.2 mm shim washer
(from 4450.56) on the top end of the shaft, followed by a blade holder, noting that the blade hol­der must be the right way round: the blade pitch arm and mixer lever must be located in front of
the blade (see drawing). The top end of the blade pivot shaft must now project into the bearing
shell of the combination bearing 1254.13.
Now pack the bearing shell with grease, and press exactly 14 steel balls into place; the grease
will prevent them rolling around and getting lost.

During the whole of this procedure the blade pivot shaft must project into the bearing shell to the
point where the balls cannot fall inward, between the blade holder and the blade pivot shaft.

Place the thrust washer of the combination bearing on top, with the ball channel on the inside,
and tighten the M5 x 12 socket-head cap screw to secure the parts.
Now turn the assembly over, so that the blade holder you have just fitted is at the bottom. Fit a

0.2 mm shim washer on the blade pivot shaft, followed by the second blade holder.

Take great care that the blade pivot shaft is not pushed back through the centre piece and blade
holder, otherwise the balls may fall out of the combination bearing you have just assembled!

Install the second combination bearing as described above, and tighten the second M5 x 12 so­cket-head cap screw.
Check the blade holders for freedom of movement, tapping a screwdriver handle on the blade
holders and centre piece to settle the bearings correctly into place; they must not be under ten­sion or strain.
The blade holders will not rotate freely if they are pushed up against the centre piece; in this
case a spacer washer 4450.57 must be fitted between the thrust washer of one of the two com­bination bearings and the blade pivot shaft.

Take care when dismantling the combination bearing to avoid the balls falling out!

Once you are confident that the blade holders rotate freely and smoothly, apply a drop of thread­lock fluid to the M5 x 12 socket-head cap screws and tighten them fully and permanently. If a
brass spacer washer 4450.57 has been fitted, ensure that the socket-head cap screw is tighte­ned with great care to avoid distorting the washer.

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3.3 Installing the auxiliary rotor

Assemble and install the rocker 4618.27 as shown in the drawing. The hole in the pivot pin

4618.28 must line up with the through-hole in the rocker, so that the flybar can be fitted through
it later without jamming or binding. Secure each ballrace by fitting an M2 x 4 screw in the centre
piece on each side. Check that the rocker swivels freely.

Press the ballraces 4618.6 into both sides of the rocker. Slide the flybar 4618.67 through the
rocker and set it exactly central, so that it projects by an equal length from both bearings.

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Roughen the flybar with abrasive paper at the point where the control bridge 4618.37 will be
clamped, and screw the control bridge in place, applying thread-lock fluid between flybar and
control frame; this prevents the flybar rotating in the control bridge during violent aerobatic
manoeuvres. Slide the ball collets 4607.36 onto both ends of the flybar and position them butting
up against the control bridge. The ball collets are secured with M3 x 3 grubscrews, but be sure
to apply thread-lock fluid to the threaded holes in the collets before fitting the screws. Press the
double ball-links 4607.35 onto the ball collets as shown.
Apply thread-lock fluid to the holes in the paddles 4448.134, and screw them onto the ends of
the flybar to a depth of exactly 15 mm. Set the paddles exactly parallel to each other and to the
control bridge.

Press an M3 nut into the recess in one side of the rotor head centre piece. Apply thread-lock
fluid to the two guide pins 4450.44 for the collective pitch compensator and push them into
place.

Make up two straight and two cranked pushrods as shown in the drawing.

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3.4 Installing the main rotor head

Fit the main rotor head on the main rotor shaft.
Ensure that the hole in the rotor head lines up with the top cross-hole in the main rotor shaft,
then fit the special screw 4618.87 and tighten it firmly to retain the rotor head.

Connect the previously prepared pushrods 4618.150 and 4618.151 as shown in the drawing.
Note that the two arms of the mixer levers 4448.132 are of different length. The double ball-links
attached to the flybar must be pressed onto the longer arms of the levers; the short pushrods
run from the shorter inner arms to the swashplate.

The cranked pushrods 4618.150 now have to be adjusted to obtain the maximum possible
collective pitch range. This is the procedure:

Slide the swashplate up as far as it will go, disconnecting the ball-links on the outer ring if
necessary.
The swashplate should just make contact with the collective pitch compensator when the
compensator itself butts up against the bottom edge of the main rotor head.

If this is not the case, adjust the cranked pushrods as follows:

• The swashplate strikes the collective pitch compensator, but there is clearance between the
collective pitch compensator and the rotor head: -> shorten both pushrods.

• The collective pitch compensator strikes the rotor head, but there is clearance between the
swashplate and the compensator: -> lengthen both pushrods.

In either case it is essential that you always alter both pushrods by exactly the same amount, so
that they remain the same length.

Now carry out the fine adjustment of the auxiliary rotor: the Hiller paddles must be parallel to the
swashplate when the swashplate is exactly horizontal. If necessary, carry out a correction by
adjusting the pushrods 4618.150 by the same amount; never adjust one pushrod on its own!

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4. Assembling the tail rotor gearbox

(bag UM-11, 11A)

Fit the bevel gear 4618.38 on the tail rotor shaft 1221, as shown in the drawing. Apply thread­lock fluid to the threaded holes in the bevel gear, then tighten the M3 x 3 grubscrews; note that
one of the two grubscrews must engage squarely on the machined flat in the tail rotor shaft.
Don’t over-tighten the grubscrews - the bevel gear could then be forced out of shape and run out
of true. Fit the spacer sleeve 4450.28 and the ballraces 4618.69 and 4450.22 on the tail rotor
shaft, pushing them hard up against each other. Push this assembly into the tail rotor housing

4448.73 as far as it will go, and secure it with the M2 x 4 retaining screw. Check that there is
absolutely zero axial play in the shaft; fit 5/10 x 0.1 mm shim washers to take up any slack if
necessary. Dismantle the assembly again, apply bearing retainer fluid, Order No. 951, to the
bearings and slide them into place. Assemble all the parts again permanently.

Fit the ballraces 4618.69 and the spacer 4618.66 on the tail rotor input shaft 4448.40 as shown
in the illustration. Apply bearing retainer fluid, Order No. 951, before fitting the bearings.
The bearings must not be under stress; if necessary tap on them using a screwdriver handle or
similar, so that they automatically seat correctly on the shaft. Allow the bearing retainer fluid to
dry.
Fit a 5/10x0.1shim washer and a bevel gear 4618.38 on the tail rotor input shaft 4448.40 as
shown in the illustration without using bearing retainer fluid at this stage.
Fit and tighten the M3 x 3 grubscrews in the bevel gear. Note that one of the two grubscrews
must engage squarely on the machined flat in the tail rotor input shaft.

Now fit the prepared drive shaft assembly into the tail rotor housing, and line up the hole in the
spacer 4618.66 with the hole in the tail rotor housing, then secure it with an M2 x 5 countersunk
screw.
Fit a steel rod (screwdriver blade or similar) through the threaded holes in the coupling 4448.40.
Using the rod as a handle, pull hard on the coupling (against the countersunk screw joint), so

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that the tail rotor drive assembly seats itself in the housing with maximum possible gear meshing
clearance between the bevel gears, as if under maximum load. Now check that the tail rotor
gearbox runs smoothly, with just detectable meshing clearance in the bevel gears.

If the play in the gears is too slight, i.e. the gears are stiff to move, you will need to remove the
drive assembly again and remove the shim washer under the bevel gear. If, however, there is
too much play in the gear meshing insert additional shim washers. If you work carefully, making
small adjustments, it is possible to set up the bevel gears so that they work freely but without
backlash. Reinstall the unit, repeat the pulling procedure as described above, and you should
find that the gear meshing clearance is correct.

Note: if you still cannot set the gear meshing clearance to your satisfaction, the problem may be
that the bevel gear on the tail rotor shaft is located too far outward due to manufacturing
tolerances, and is not engaging correctly with the bevel gear on the input shaft. If this is the
case, you will find that the tips of the teeth of the bevel gear 4618.41 are already fouling the
spacer sleeve 4450.28A, and yet there is backlash in the meshing clearance. In this case you
must fit the shim washers between the bevel gear 4618.38 and the bearing 4450.22, instead of
between the spacer sleeve and the bearing 4618.69, until the desired slight meshing clearance
is present.

Now remove both assemblies again, apply bearing retainer fluid, Order No. 951, to the bearings,
the setscrews, and the bevel gear on the input shaft, re-fit them on the tail rotor shaft and the
input shaft, and assemble the parts permanently.

Fit a 3 mm Ø washer and the tail rotor bellcrank 4618.60 on the M3 x 22 socket-head cap screw
as shown.

Check that the bellcrank rotates smoothly on the screw; if necessary de-burr the hole in the
bellcrank and lubricate it with silicone oil. Fit the screw (with bellcrank fitted) into the hole in the
shoulder of the tail rotor housing and tighten it by a few turns; don’t tighten it fully at this stage,
because the control bridge must first be installed as described in the next section.

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5. Installing the control bridge

(bag UM-11B)

Press the ballraces 4607.137 into the control ring 4448.62 as far as they will go. Apply a little
thread-lock fluid to this assembly (don’t let it run between control ring and control sleeve!) and
push it onto the control sleeve (from 4618.61) in such a way that the inner ring of the ballrace
butts up against the flange of the control sleeve.

Attach the two ball-links 4618.55 to the control bridge (from 4618.61), fit the bridge on the
control sleeve and press it against the inner ring of the other ballrace. Fit the shakeproof washer

1291.26 on the control sleeve and press it against the control bridge.
Now check that the control ring is free to rotate on the control bridge, but that there is absolutely
no axial play present. If the ring is stiff to move, there is probably tension between the two ballra­ces; this can usually be corrected by tapping with a screwdriver handle, as already described.
Fit the control bridge on the tail rotor shaft, then fit the bellcrank over the ball on the control ring
and tighten the M2 x 16 screw; the bellcrank and the control bridge should now rotate freely, but
without slop.

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6. Assembling the tail rotor head

(bag UM-11C)

The tail rotor head is assembled as shown in the drawing; be sure to grease all the bearings.

Fit the two O-rings in the hub 4448.22 and check that they rest snugly in the two channels. Oil
the rings, and fit the tail rotor head on the tail rotor shaft with the cross-hole in the shaft lined up
with the hole in the hub. Push the dowel pin 4448.22 through the holes, and fit the M3 x 3
grubscrew in turn to secure the pin.

Check that the hub is the right way round, as shown in the drawing.

Fix the tail rotor blades in the blade holders using two M3 x 20 screws. Tighten the tail rotor
blade retaining screws just to the point where the blades can still swivel, so that they are able to
take up their optimum position naturally when rotating.

Note the orientation of the tail rotor blades: the tail rotor rotates clockwise (bottom blade forward)
when viewed from the left-hand side; the blade pitch arms on the blade holders must be forward
of the blades.

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7. Tail boom

7.1 Assembling the tail boom struts

(bag SKR-1)

Press two strut ends 1292.11 into each of the two aluminium tail boom struts 4445.8 and 4475.8
as far as they will go, and set them parallel to each other. Drill 1.5 mm Ø pilot-holes in the struts
where the strut ends are located, and fit 2.2 x 6.5 mm self-tapping screws to secure the ends.

Apply bearing retainer fluid to the M3 x 25 studs, and screw them into the two cabin stand-off
pillars 4445.12. Screw them in as far as they will go, and allow the fluid to cure fully.

7.2 Preparing the mechanics to accept the tail boom

Fix the tail boom mounting bracket 1292.5 to the bearing holder 4448.14 (part of the main me­chanics) using two M3 x 16 socket-head cap screws. Press the M3 x 12 socket-head cap screw
and M3 nut into the clamp and temporarily tighten the screw. Undo the screw again to the point
where the tail boom can be slid into place later.

7.3 Preparing the tail boom

(bag SKR-2)

The tail boom features a curve at the front end, with the effect that the tail boom rises towards
the tail rotor. This has a dual purpose: it increases the tail rotor ground clearance, and also
means that the tail rotor drive shaft runs in a broad curve, and therefore cannot run out of true.
Push the two shaft bushes 1292.10A into the tail boom 4445.9 using a tool such as a length of
beech dowel: the front bush should be 200 mm from the front end of the boom, the rear bush
300 mm from the tail end; the spherical recess of each bush should face forward. Now press the
guide ring 4451.7 into the tail boom from the front, with the tapered opening facing the tail, and
position it exactly 27 mm from the front end of the tail boom. The purpose of this ring is to guide
the retaining sleeve accurately over the yoke of the quick-release coupling.

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The front shaft coupling can now be prepared. Note that it must be possible for the coupling to
engage perfectly inside the tail boom without you observing the process or helping with tools ­both of which are impossible. For this reason it is important to ensure that the brass coupling
sleeve 4618.58 is an easy sliding fit over the coupling yoke 4618.57. Remove any rough edges
from the yoke, and reduce its diameter slightly with fine abrasive paper if necessary. Fit the tail
rotor drive shaft, Order No. 4451.19, fully into the coupling sleeve, so that the pre-formed end
rests inside the sleeve. Now fit a grubscrew in the collet 56.0 and slip it onto the tail rotor shaft
behind the sleeve. Push the tail rotor shaft into the coupling yoke as far as it will go, then slide
the sleeve over the yoke in the same way. Position the collet about 1 mm behind the sleeve, and
tighten the grubscrew to fix it to the tail rotor shaft.

7.4 Completing the tail boom

Fit the tail rotor bracket 4475.107 on the rear end of the tail boom, and fit the strut bracket

1292.6 on the boom from the front, as shown in the drawing. Note that the gap (clamp section)

of the strut bracket must be at the bottom, with the integral bored lug on the left-hand side.

7.5 Checking the length of the tail rotor drive shaft

Remove the tail rotor drive shaft from the mechanics, oil it lightly and slip it through the shaft
bushes, rotating it all the while, until the rear end exits the tail end of the boom and can be fitted
into the tail rotor coupling. Slide the shaft in as far as it will go, then pull it back by 1 mm and
temporarily tighten the grubscrews to secure the coupling. (In use the front end of the tail rotor
shaft must have about 1 mm clearance in the coupling yoke, and this is obtained automatically
when the shaft is eventually pushed into the tail rotor coupling as far as it will go.) The tail boom
can now be fitted temporarily into the tail boom bracket 1292.5; push the tail boom fully onto the
bearing holder 4448.14 and secure it by tightening the clamp in the boom bracket. Fit the tail
rotor into the rear end of the tail boom, and rotate the tail rotor drive shaft to ensure that it
engages in the quick-release coupling on the main gearbox at the front end. It should now be
possible to push the tail rotor into the tail boom to the point where it butts up against the bracket,
without the drive shaft fouling the end of the quick-release coupling at the front. If this is not
possible, the tail rotor shaft needs to be shortened; alternatively you can re-position the tail rotor
gearbox bracket 4475.107 slightly further aft. When you are satisfied, remove the tail boom from
the mechanics again.

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7.6 Connecting the tail boom to the mechanics

Withdraw the tail rotor from the tail boom to the point where the shaft coupling becomes
accessible. Undo the grubscrews in the shaft coupling so that the tail rotor shaft 4451.19 can be
pulled out of the coupling. Now carefully de-grease the shaft, push it into the shaft coupling as
far as it will go and tighten the grubscrews to secure it. This is the procedure: first remove the
grubscrews from the coupling entirely, apply thread-lock fluid, Order No. 952, or bearing retainer
fluid, Order No. 951, to the threaded holes, then fit the grubscrews again and tighten them fully.
If possible, grind a flat in the shaft at the engagement point of the grubscrews on one side, to
optimise the strength of the joint. Fix the tail rotor to the tail rotor gearbox bracket 4475.107
using three 2.9 x 13 mm self-tapping screws. Apply a little grease to the quick-release coupling
and to the front end of the tail rotor shaft.
Fix the struts to the left and right mechanics side frames using the stand-off pillars 4445.12
prepared in Section 7.1.

The complete tail boom assembly can now be pushed into the mounting bracket 1292.5 as far
as it will go, checking carefully that the quick-release coupling engages correctly. Rotate the tail
boom so that the tube curves upwards, with the curve exactly in the vertical plane when viewed
from the tail. Rotate the tail rotor bracket so that the tail rotor shaft is at right-angles to the main
rotor shaft when viewed from the tail. Tighten the M3 x 12 socket-head cap screw in the moun­ting bracket to clamp the boom in its final position. We recommend that you hold the tail boom
pointing vertically upwards while you tighten the clamping screw.
Adjust the position of the rear tail boom strut bracket 1292.6 so that the upper tail boom struts

4445.8 can be attached to it using an M3 x 30 mm socket-head cap screw and M3 self-locking
nut, as shown in the drawing. Now attache the lower tail boom struts 4475.8 to the support
clamp using another M3 x 30 mm socket-head cap screw, but without tightening this screw.
At the front end the struts are attached to the main frame using 2.9 x 16 mm self-tapping
screws; if there are 2.9 x 13 mm self-tapping screws from earlier installation, they have to be
removed first.
The position of the support bracket is given by the length of the four struts; tighten the clamping
screw in the strut bracket firmly in this position, then drill 1.5 mm Ø holes through the tail rotor
bracket 4475.107 and the tail boom bracket 1292.5 and into the tail boom. Fit 2.2 x 6.5 mm self­tapping screws in the holes and tighten them to prevent any of the parts shifting or rotating in
flight.

7.7 Stabiliser panels

(bag SKR-3)

Fix the vertical stabiliser to the tail rotor bracket using 2.9 x 13 mm self-tapping screw. Slip both
halfes of the horizontal stabiliser bracket on the tail boom from above and from below, then po­sition the horizontal stabiliser on top of it and lock it in place by two M3 x 30 mm socket-head

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cap screws and M3 self-locking nuts. Position the horizontal stabiliser bracket 200 mm forward
of the tail rotor bracket, and set the horizontal stabiliser at right-angles to the vertical stabiliser.
Tighten the screws firmly.

8. Installing the skid landing gear

(bag SR-4)

Fit the skid tubes 4447.7 through the skid bars 4447.6 and slide them along until the distance
between the fixing screw holes is 207 mm.

The skid landing gear can now be attached to the model using two M3 x 16 socket-head cap
screws at the rear and two M3 x 20 socket-head cap screws at the front; don’t forget to fit the
spacer sleeves 4451.5 at the front as shown. Set the skid tubes exactly parallel to each other,
and slide them through the skid bars until they both project by about 50 mm beyond the rear skid
bars. The skids are fixed to the skid bars using 2.2 x 6.5 mm self-tapping screws fitted from the
inside as shown; drill 1.5 mm Ø pilot-holes through the skid bars and into the skids before fitting
the screws. Epoxy the sealing plugs in the skid tubes.

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9. Tail rotor control system

(bag SKR-5)

The tail rotor control system is based on a cantilever carbon fibre pushrod.
Screw a ball-link onto one end of each of the M2.5 x 75 mm threaded rods to a depth of about 7
mm. Slip the pushrod strut onto the CFRP tube, then glue the M2.5 x 75 threaded rods into both
ends using slow-setting epoxy, e.g. UHU-Plus endfest 300, Order No. 950. At the front end the
ball-link on the threaded rod should butt up directly against the CFRP tube. At the rear end the
threaded rod should be positioned as shown in the drawing, i.e. projecting to the point where the
distance between the centres of the two ball-link sockets is exactly 843 mm.

Fit a linkage ball onto an M2 x 8 screw, fit the screw in the outermost linkage hole in the bell­crank, and secure them with an M2 nut. Be sure to apply thread-lock fluid, Order No. 952, to the
screws and nut.

Attach a linkage ball to the output arm of the tail rotor servo using an M2 cheesehead screw and
nut. Connect the prepared carbon fibre pushrod to the servo at the front and to the tail rotor ac­tuating arm at the rear. Fix the pushrod strut to the support flange as shown in the drawing using
an M3 x 12 screw and self-locking nut. Take care to position the pushrod strut in such a way that
the pushrod is not under tension, and moves to and fro without exerting any noticeable pressure
on the strut.

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10. Cabin

(bag SKR-6)

10.1 Installing the front cabin support system

Fix the two cabin stand-off pillars to the brackets at the front of the sub-structure by fitting M3 x
12 socket-head cap screws from the rear.

10.2 Attaching the cabin

Press two rubber grommets 3515.3 into the holes in the former 4475.17, and secure them with a
drop of cyano on one side. Push the former onto the pillars mounted at the front of the
mechanics, with the curved side at the bottom, and check that the pillars engage completely in
the rubber grommets.
Press two rubber grommets in the 7 mm Ø holes in the cabin. Slip the cabin over the mechanics
from the front, and engage the two stand-off pillars at the top in the rubber grommets in the
cabin.
Raise the cabin at the front until the former attached to the mechanics makes contact with the
bottom of the cabin moulding.
Glue the former to the cabin in this position using Stabilit express. Allow the adhesive to cure
completely, then remove the cabin as follows: first ease it off the rear stand-off pillars at both
sides, and then slide it forward; it should come off easily. It should be just as easy to re-fit it by
reversing the procedure.

Run the receiver aerial along the mechanics to a point aft of the front skid bar, so that the cabin
can easily be lifted off without snagging the aerial. Fit the plastic guide tube for the aerial through
the two loops on the inside of the skid bars, and fit small pieces of fuel tubing on it to prevent it
slipping out of the sleeve. The flexible aerial wire can then be run along the skid bar, slipped into
the guide tube from the front, and allowed to trail out of the tube at the rear.

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11. Main rotor blades

This model should be operated using GRP or CRP main rotor blades to obtain an optimal effi­ciency. Nevertheless it is possible to use wood blades (by your own resposibility). These have to
be prepared as decribed in the next section 11.1. If you use GRP/CRP blades you can skip this
section.

11.1 Preparing wood rotor blades

If your rotor blades do not come with the bushes factory-fitted, epoxy the root bushes 4607.164
in the holes in the rotor blades.
When the epoxy has cured, rub down the blades all over using fine abrasive paper, Order No.

700.1 or 700.2.
Ideally the weight of both blades will be identical, as will the Centre of Gravity (balance point) of
both blades. You can check this by balancing the blades individually over a triangular-section
block as shown in the drawing. Mark the line of balance in both directions; the point where the
lines cross is the blade’s Centre of Gravity.
In practice it is unlikely that both blades will be identical in this way, and it can be difficult to
achieve perfection using ordinary methods. However, this is not crucially important with modern
model helicopters. What is crucial is that both blades should possess identical moments when
mounted on the rotor head. This means that it is permissible for the blades to be different
weights, provided that the difference is compensated by differing blade CGs; the method of
balancing them is described in the next section.
Apply clear dope (SPANNFIX IMMUN, Order No. 1408) to the root end of the blades, the area of
the doublers (approximately 70 mm long) and the extreme tip (around 20 mm long), and apply a
colour finish to those areas. The film is applied to the blades as shown in the drawing; first the
top surface, then the underside of the trailing edge, then the rest of the underside, overlapping at
the trailing edge. It is important that the film should be applied smoothly, without wrinkles!

11.2 Balancing the rotor blades

Screw the main rotor blades together as shown, and hang them up on a piece of thread. Apply
adhesive tape to the end of the lighter blade until the joined blades hang level.
Balance the blades carefully in this way to ensure that your main rotor does not vibrate when
spinning!

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12. Setting up

12.1 Setting up the cyclic control system

The basic settings for the roll-axis and pitch-axis control systems should already be correct if
you have installed the linkages exactly as described in the instructions. Since the instructions
include the lever lengths (correct linkage holes), the final setting up is carried out using the
electronic facilities provided by your transmitter. Note that the servo travel should not be set too
high, and ensure that the swashplate does not strike its end-stops on the main rotor shaft at
either end-point of the transmitter stick travel for roll-axis and pitch-axis movements, as this
would mean that the collective pitch control could not move freely in the axial direction.

12.2 Main rotor pitch settings

Main rotor pitch is measured using a pitch gauge (optional accessory, not included in the kit).
The following table shows the recommended basic settings, but the optimum values may well
vary from model to model according to the rotor blades you are using.

Minimum Hover Maximum
Hovering and practice -2° 5,5°...6° 12°
Aerobatics -4° 5°... 5,5° 8°... 9°
Auto-rotation -4° 5,5° 13°

The best way of setting the correct blade pitch on the transmitter is as follows:

1. Measure the hovering pitch and set it to the correct value.

2. Measure collective pitch maximum and minimum and adjust the values according to the

following diagrams using your transmitter's collective pitch curve facility.

12.3 Setting up the motor control system

The following diagrams show two alternative motor control curves:

• The „normal“ power curve is suitable both for hovering and normal circuits.

• Since the motor does not stop at any setting of the collective pitch stick when the

„Aerobatics“ power curve is set, this curve must only ever be selected when the model is in
flight.

• The values stated above can only be a guideline, as they vary greatly according to the motor

used; there is no alternative but to fine-tune them during the test-flying programme.

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12.4 Further adjustments

If you have made up all the linkages exactly as described in the previous sections, no changes
to the mechanical arrangements will be necessary. The following adjustments can all be carried
out at the transmitter:

1. Servo direction
Set the „sense“ (direction of rotation) of all servos as stated in the instructions. Check the
direction of the speed controller in particular!

2. Dual Rates
You can set switchable travels for roll-axis, pitch-axis and tail rotor. As a starting point we
recommend 100% and 75% as the two settings.

3. Exponential
For the basic set-up you should leave all control systems set to „linear“.

4. Servo travel centre offset
Do not make any adjustments to this point. At a later stage you may wish to make minor
corrections here.

5. Adjusting servo travel
This is where you can adjust the maximum servo travel. Note that the travels should always
be the same on both sides of neutral, otherwise you will end up with unwanted differential
effects:

Fo
r the swashplate servos (collective pitch function) it is important to check that servo travels
are symmetrical, i.e. with the same values for both directions. The collective pitch function of
the swashplate servos should produce a range of blade pitch angles covering -5° to +13°,
also with symmetrical travels; you may find it necessary to remove the servo output arm,
move it round by one spline and fit the retaining screw again.
The mechanics should now be set up virtually perfectly. When the collective stick is at centre
(hover point), collective pitch should be about 5.5°, and the speed controller should be at the
half-way point between stop and full-throttle.
Note:
The collective pitch and power curves can be adjusted later to meet your exact personal
requirements. However, if you have already set differential travels in the basic set-up
procedure, as shown in diagram „B" above, any fine adjustments required subsequently will
be more difficult!

6. Collective pitch and power curves
These adjustments are of fundamental importance to the flight performance of any model
helicopter. The aim of the procedure is to maintain a constant rotor speed when the model is
climbing and descending, i.e. regardless of load. This then represents a stable basis for
further fine-tuning, e.g. of the torque compensation system etc. (see also „Collective pitch
and power curves“).

7. Static torque compensation
The tail rotor servo is coupled to the collective pitch function via a mixer in the transmitter in
order to compensate for torque changes when you operate the collective pitch control. On
most transmitters the mixer input can be set separately for climb and descent.
Recommended values for the basic settings are: climb: 35%, descent: 15%.

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8. Gyro adjustment

Gyro systems damp out unwanted rotational movements around the vertical (yaw) axis of the
model helicopter. They do this by detecting the unwanted motion and injecting a
compensatory signal into the tail rotor control system, and in order to achieve this effect the
gyro electronics are connected between the tail rotor servo and the receiver. Many gyro
systems also allow you to set two different values for gyro gain, and switch between them
from the transmitter via a supplementary channel. The extra channel is controlled via a
proportional slider or rotary knob, or a switch, depending on the gyro system.

If your gyro features an adjustor box with two rotary pots for two fixed settings, and you can
switch between them from the transmitter, it is best to set one adjustor approximately to
centre (50%), and the other to 25%. If the gyro system provides proportional control between
the two set values, then the one pot should be set to „0", the other to about 80%.

If you have a gyro system whose effect cannot be adjusted from the transmitter, i.e. there is
only a single adjustor on the gyro electronics itself, the pot should be set to 50% gain as a
starting point.

Check that the direction of the gyro’s compensatory action is correct, i.e. that it responds to a
movement of the tail boom with a tail rotor response in the opposite direction. If this is not the
case, any yaw movement of the model will be amplified by the gyro! Most gyro systems are
fitted with a change-over switch which reverses their direction, and this must then be moved
to the appropriate position. However, some systems have no such switch, and in this case
the solution is to mount the gyro inverted.

One factor which all gyro systems have in common is that flight testing is necessary in order
to establish the optimum settings, as so many different factors influence the settings.

The aim of the gyro adjustment process is to achieve as high a level of gyro stabilisation as
possible, without the gyro causing the tail boom to oscillate.

13. Final checks before the first flight

When you have completed the model, run through the final checks listed below before carrying
out the first flight:

• Study the manual again and ensure that all the stages of assembly have been completed
correctly.

• Check that all the screws in the ball-links and brackets are tightened fully after you have
adjusted gear meshing clearance.

• Can all the servos move freely, without mechanical obstruction at any point? Do they all
rotate in the correct direction relative to the stick movements? Are the servo output arm
retaining screws in place and tight?

• Check the direction of effect of the gyro system.

• Ensure that the transmitter and receiver batteries are fully charged. We recommend using a

voltage monitor module to check the state of charge of the receiver battery on the flying
field.

Don’t attempt to fly the helicopter until you have successfully checked everything as described
above.

14. Maintenance

Helicopters, whether large or small, place considerable demands on maintenance. Whenever
you notice vibration in your model, take immediate steps to reduce or eliminate it. Rotating parts,
important screwed joints, control linkages and linkage junctions should be checked before every
flight. If repairs become necessary be sure to use original replacement parts exclusively. Never
attempt to repair damaged rotor blades; replace them with new ones.

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15. Adjustments during the first flight
Blade tracking

„Blade tracking“ refers to the height of the two rotor blades when they are spinning. The
adjustment procedure aims at fine-tuning the pitch of the main rotor blades to exactly the same
value, so that the blades rotate at the same level.

Incorrectly set blade tracking, with the blades revolving at different heights, will cause
the helicopter to vibrate badly in flight.

When you are adjusting blade tracking you are exactly in the „firing line“ of the blades,
so keep at least 5 metres away from the model in the interests of safety.

You can only check blade tracking if you are able to see clearly which blade is higher and which
is lower. The best method is to mark the blades with coloured tape as follows:

There are two alternative methods: figure „A“ shows the use of different colours on the blade
tips; fig. „B“ shows the use of the same colour, but applied at different distances from the blade
tip.

Procedure for adjusting blade tracking

1. Set the helicopter to the point where it is almost lifting off, then sight directly along the rotor
plane.

2. If you can see that the rotor blades are running in the same plane, no adjustment is
required; however, if one blade is running higher than the other, the settings must be
corrected.

3. Locate the pushrods between the swashplate and the mixer levers; the adjustment is made
at the ball-links on both ends of these pushrods: unscrew the links to raise the blade, screw
them in to lower it.

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16. General safety measures

• Take out adequate third-party insurance cover.

• If at all possible join the local model flying club.

At the flying site:

• Never fly your model above spectators.

• Do not fly models close to buildings or vehicles.

• Avoid flying over agricultural workers in neighbouring fields.

• Do not fly your model in the vicinity of railway lines, major roads or overhead cables.

Pre-flight checks, flying safety:

• Before you switch on the transmitter, check carefully that no other model flyer is using the
same frequency.

• Carry out a range check with your RC system.

• Check that the transmitter and receiver batteries are fully charged.

• Do not let the model fly out of safe visual range.

Post-flight checks:

• Clean the model carefully and check that all screws etc. are still tight.

• Look for wear and damage to the helicopter, and replace worn parts in good time.

• Ensure that the electronic components such as battery, receiver, gyro etc. are still securely

fixed. Remember that rubber bands deteriorate with age and will eventually fail.

• Check the receiver aerial. Conductor fractures inside the insulation are often not visible from
the outside.

• If the main rotor should touch the ground when spinning, always replace the blades. Internal
blade damage may not be visible from the outside.

• Never carry the model by the tail boom: too firm a grip will easily deform the tail rotor
pushrod.

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17. Some basic terms used in model helicopter flying

The term „rotary wing machine“ indicates that the helicopter’s lift is derived from rotating „wings“
which take the form of rotor blades. As a result, a helicopter does not require a minimum forward
speed in order to fly, i.e. it can hover.

Cyclic pitch

Cyclic pitch variation is used to steer the machine around the roll and pitch axes. Changing
cyclic pitch has the effect of altering blade pitch depending on its position in the circle. The effect
is caused by tilting the swashplate, which then effectively tilts the helicopter in the required
direction.

Collective pitch

Collective pitch provides control over vertical movement, i.e. for climb and descent. The pitch of
both rotor blades is altered simultaneously.

Torque compensation

The spinning rotor produces a moment which tends to turn the whole helicopter in the opposite
direction. This effect must be accurately neutralised, and this is the task of the tail rotor. Tail
rotor blade pitch is altered to vary torque compensation. The tail rotor is also used to control the
model around the vertical (yaw) axis.

Hovering

This is the state in which the helicopter flies in a fixed position in the air, without moving in any
direction.

Ground effect

This occurs only when the machine is close to the ground, and it falls off as altitude rises. At an
altitude of about 1 - 1.5 times the rotor diameter ground effect is completely absent. Normally the
revolving airflow from the main rotor is able to flow away freely, but in ground effect the air
strikes an obstacle (the ground) and forms an „air cushion“. In ground effect a helicopter can lift
a greater weight, but its positional stability is reduced, with the result that it tends to „break away“
in an unpredictable direction.

Climb

Any excess power above that required for hovering can be exploited to make the helicopter
climb. Note that a vertical climb requires more energy than an angled climb which includes
forward motion. For this reason a model with a given amount of motor power will climb more
rapidly at an angle than vertically.

Level flight

A helicopter absorbs least power when flying straight and level at about half-power. If you have
trimmed the machine carefully for a steady hover, it will tend to turn to one side when flown
forward. The reason for this phenomenon is that the rotor blade which is moving forward
encounters an increased airflow caused by the wind, and this increases its upthrust compared
with the blade which is moving downwind, where the same airflow has to be subtracted. The net
result is a lateral inclination of the helicopter.

Descent

If the helicopter’s rotor speed is relatively low and you place the helicopter in a fast vertical
descent, the result can be that insufficient air flows through the rotor. This can cause what is
known as a „turbulent ring stage“, when the airflow over the blade airfoil breaks away. The
helicopter is then uncontrollable and will usually crash. A high-speed descent is therefore only
possible if the helicopter is moving forward, or if the rotor is spinning at high speed. For the
same reason care should be exercised when turning the model helicopter downwind after flying
into wind.

Flapping motion of the rotor blades

As we have already seen, the forward-moving blade produces greater upthrust than the trailing
blade. This effect can be minimised by allowing the leading blade to rise and the trailing blade to
fall. The rotor head is fitted with what is known as a flapping hinge to allow this movement, and

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43

this prevents the rotor plane tilting excessively in forward flight. In model helicopters a single
hinge shared by both blades has proved an effective solution to the problem.

Auto-rotation

This term refers to a helicopter flying without motor power. The rotational speed of the main rotor
can be kept high by setting both blades to negative pitch, and the airflow through the rotor as it
descends then keeps the blades turning. The rotational energy stored in the rotor by this means
can be converted into upthrust when the helicopter is close to the ground, by the pilot applying
positive collective pitch. Of course, this can only be done once, and it has to be done at the
correct moment. Auto-rotation allows a model helicopter to land safely when the motor fails, just
like a full-size machine.

However, auto-rotation places considerable demands on the pilot’s judgement and reflexes; you
can only halt the machine’s descent once, and you must not „flare“ too early or too late. Much
practice is required to get it right.

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Notes

Best.-Nr. 4475

GRAUPNER GmbH & Co. KG D-73230 KIRCHHEIM/TECK GERMANY

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Summary of

replacement parts

Date of issue 12/06

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Main gearbox

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3

Graupner
Order No.

Description Dimensions

[mm]

No. off

reqd./pack

1291.10 Pushrod 2,5Øx75 lg 3 / 4

4448.8 Dome bearing holder 1

4448.11B Lower layshaft bearing holder, bored 1

4448.12 Main rotor shaft bearing holder 1

4448.14 Main rotor shaft bearing holder 1

4450.7 Tail rotor drive bearing holder 1

4450.31 Ballrace 6/16x5 2 / 1

4450.20A Ring gear 1

4450.37 Dowel pin 3Øx28 1

4450.24 Ballrace 10/19x5 2 / 1

4450.40 Shim washers for main rotor shaft 10/16 x
0,1/0,2

3 each

4450.41 Pinion 1

4450.43 Main rotor shaft 1

4475.09 Mechanics side frame, left 1

4475.10 Mechanics side frame, right 1

4475.11 Upper layshaft bearing holder, aluminium

1

4475.27 Motor mount support 1

4607.156 Circlip

∅ 10

1

4618.6 Ballrace 4/13x5 2 / 1

4618.155 Ball-links for M2,5

Linkage ball

6 / 10

2 / 10

4618.57 Yoke shaft 1

4618.58 Quick-release coupling sleeve 1

4618.65 Roll pin 2x16 1

4618.81 Shim washers 6/12x0,1/0,2 2 each

4618.105 Plastic gear and freewheel

∅ 55

1

4618.107 Freewheel sleeve 1

4618.113 Swashplate guide and brass sleeve 1

4682.45 Swashplate 1

56.0 Collet for tail rotor drive shaft 2,1/6x4,5 1 / 10

107 Grubscrew M3x3 3 / 10

560.4 Washer Ø3,2/8x0,5 10 / 10

565.16 Socket-head cap screw M3x16 22 / 20

565.20 Socket-head cap screw M3x20 2 / 20

704.10 Cheesehead screw M2x10 2 / 20

704.12 Cheesehead screw M2x12 2 / 20

710 Hexagon nut M2 2 / 20

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Sub-structure

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Graupner
Order No.

Description Dimensions

[mm]

No. off

reqd./pack

1291.21A Skid brackets, plastic 6 / 4

4448.34 Front structure side frame 2 / 1

4448.101 RC Box 1

4450.17 Long spacer 2 / 1

4450.18 Rear bulkhead, plastic 1

4450.34A Spacer sleeve 4

4475.100 Battery holder, CRP, consisting of:
Side
Bottom
Plastic spacer set

2
1
1

4475.101 Upper part frame, CRP
Switch hoder, CRP

2

1

4475.102 Spacer, aluminium
Spacer, aluminium

Ø8x60 lg
Ø8x22 lg

2
2

560.4 Washer Ø3,2/8x0,5 6 / 10

565.10 Socket-head cap screw M3x10 4 / 20

565.12 Socket-head cap screw M3x12 4 / 20

565.16 Socket-head cap screw M3x16 4 / 20

746.7 Self-tapping screw 2,9x6,5 2 / 20

746.13 Self-tapping screw 2,9x13 8 / 20

746.16 Self-tapping screw 2,9x16 2 / 20

747.10 Self-tapping screw 2,2x9,5 16 / 20

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6

Motor

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Graupner
Order No.

Description Dimensions

[mm]

No. off

reqd./pack

4475.05 Aluminium motor mount 1

4475.06

Motor pinion holder, consisting of:
Follower disk, aluminium
Split taper collet, steel
Washer
Hexagon nut

Ø 8mm
Ø 8mm
M8x1

1
1
1
1

4475.07 Pinion, Delrin 28 Z. / Mod. 1 1

4475.08 Pinion, Delrin 32 Z. / Mod. 1 1

560.4 Washer Ø3,2/8x0,5 4 / 10

565.10 Socket-head cap screw M3x10 2

565.12 Socket-head cap screw M3x12 2

566.5 Socket-head cap screw M4x5 4

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Main rotor

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Graupner
Order No.

Description Dimensions

[mm]

No. off

reqd./pack

1252.11 Blade holder 2

1254.13 Axial bearing 2

4448.37 Control bridge, 3-part 1

4448.132

4444.132A

Mixer lever set, cons. of:
Mixer lever
Ballrace
Brass sleeve,
Brass spacer washer,
Cheesehead screw
Brass linkage ball

7/3x3
5/3x4
5/3x0,6
M2x10

2
4
2
2
4
4

4448.134 Flybar paddle 2

4448.135 Plastic double link 2

4450.44 Steel pin 2x28 2

4607.28 O-ring 2

4607.31 Ballrace 8/16x4 2

4607.36 Brass ball collet 2

4618.6 Ballrace 4/13x5 2

4618.27 Rocker, 2-part 1

4618.28 Steel pivot pin 1

4618.29 Ballrace 3/10x4 2

4618.46 Collective pitch compensator hub 1

4618.47A Collective pitch compensator, complete 1

4618.48A Collective pitch compensator arm
Brass pin, bored
Brass pin
Circlip

2,3

1
1
1
3

4618.151 Straight pushrod M2,5x60 2

4618.55 M2 ball-link and ball 2 / 10

4618.67 Flybar 1

4618.80 Special socket-head cap screw M4x35 2

4618.87 Special socket-head cap screw M3x18 1

4618.150 Cranked pushrod M2,5x75 2

4618.155 M2.5 ball-link, excl. ball 8 / 10

4682.26 Rotor head centre piece 1

4682.29 Hardened blade pivot shaft 1

107 Grubscrew M3x3 2

565.20 Socket-head cap screw M3x20 2

567.12 Socket-head cap screw M 5x 12 2 / 10

617 Self-locking nut M4 2

704.4 Cheesehead screw M2x4 2 / 20

704.8 Cheesehead screw M2x8 6 / 20

704.10 Cheesehead screw M2x10 10 / 20

710 Nut M2 8 / 20
712 Nut M3 3

As required:

4450.56 Shim washer 8/14x0,3 5

4450.57 Brass shim washer 5/8x0,5 5

4450.86 Shim washer 3/5x0,1/0,2 5

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Tail rotor

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Graupner

Order No.

Description Dimensions

[mm]

Graupner
Order No.

1220 Thrust bearing set, consisting of:

Flanged washer
Plain washer
Ball cage

2
2
2

1221 Tail rotor shaft, hardened and ground 1

1291.23 Spacer sleeve 10/8,5x 2 2

1291.26 Shakeproof washer 1 / 5

4448.22 Aluminium articulated tail rotor hub
Pin

2x18

1
1

4448.40 Shaft and coupling 1

4448.73 Tail rotor housing 1

4450.22 Ballrace 5/13x4 1

4450.28A Spacer sleeve
Shim washer

5/6x16,5
5/10x0,1

1
2

4607.137 Ballrace 6/10x2,5 4 / 1

4618.38 Bevel gear ID 5 2

4618.55 Ball-links for M2 rod, with balls 2 / 10

4618.56 Tail rotor blade holder 2

4618.60 Plastic bellcrank 1

4618.61 Brass control sleeve, and
Plastic control bridge

1

1

4448.62 Control ring with 2 balls 1

4618.66 Plastic spacer sleeve 1

4618.69 Ballrace 5/13x5 3

4682.59A Tail rotor blade 2

65 Grubscrew M4x5 2 / 10
107 Grubscrew M3x3 5 / 10

560.6 Washer Ø3,2/6x0,5 1 / 10

565.12 Socket-head cap screw M3x12 2 / 20

565.20 Socket-head cap screw M3x20 2 / 20

565.22 Socket-head cap screw M3x22 1/ 20

704.4 Cheesehead screw M2x4 1 / 20

704.10 Cheesehead screw M2x10 4 / 20

713 Self-locking nut M3 3 / 20

5882.5 Countersunk screw M2x5 1 / 20

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Tail boom

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Graupner

Order No.

Description Dimensions

[mm]

No. off

reqd./pack

1292.5 Tail boom bracket 1

1292.6 Tail boom strut bracket 1

4475.107 Tail rotor gearbox bracket 1

1292.10A Shaft bush, plastic with Teflon guide 2 / 2

1292.11 Tail boom strut end 8 / 4

4445.8 Upper aluminium tail boom strut Ø8/6 x 495 lg. 2 / 2

4475.8 Lower aluminium tail boom strut Ø8/6 x 465 lg. 2 / 2

4445.9 Curved aluminium tail boom, black 792 lg. 1 / 1

4445.12 Short mounting pillar 8Ø x 21lg, M3 2 / 2

4451.7 Plastic guide ring 1 / 1

4451.19 Tail rotor drive shaft 2Ø x784 lg. 1 / 1

5221.2 Carbon fibre tube Ø5/3 x 760 lg. 1 / 1m

565.12 Socket-head cap screw M3x12 4 / 20

565.16 Socket-head cap screw M3x16 2 / 20

565.30 Socket-head cap screw M3x30 2 / 20

Stud M3x25 2

704.8 Cheesehead screw M2x8 1 / 20

704.10 Cheesehead screw M2x10 1 / 20

710 Nut M2 2 / 20
713 Self-locking nut M3 3 / 20

746.13 Self-tapping screw 2,9x13 3 / 20

747.7 Self-tapping screw 2,2x6,5 7 / 20

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14

Cabin, stabilisers, landing gear

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15

Graupner
Order No.

Description Dimensions

[mm]

No. off

reqd./pack

4445.12 Short mounting pillar 8Ø x 21lg, M3 2 / 2

4451.5 Plastic spacer sleeve Ø8/3 x 8 2 / 2

4447.6 Plastic skid bar, black 2 / 2

4447.7

4447.7A

Aluminium skid tube, black eloxided
Plastic skid sealing plug, black

2 / 2

4 / 4

4475.01 Cabin, GRP, painted 1 / 1

4475.17 Plywood cabin retainer former

4475.104 CRP horizontal stabiliser
Plastic stabiliser mount
CRP vertical stabiliser

1 / 1

2 / 2
1 / 1

565.12 Socket-head cap screw M3x12 2 / 20

565.16 Socket-head cap screw M3x16 2 / 20

565.20 Socket-head cap screw M3x20 2 / 20

565.30 Socket-head cap screw M3x30 2 / 20

713 Self-locking nut M3 2 / 20

746.13 Self-tapping screw 2,9x13 2 / 20

747.7 Self-tapping screw 2,2x6,5 4 / 20

3513.3 Rubber grommet 4 / 10

(not shown):

Graupner
Order No.

Description Dimensions

[mm]

No. off

reqd./pack

1271 Main rotor blades, GRP, symmetrical 602x50 1 Paar

4475.99 Decal sheet (3 various decors) 1

951 Loctite bearing retainer fluid 603 1
952 UHU thread-lock fluid 1

4467.90 Spiral tubing 1m

1521.52 Cable tie 10 / 5

1521.55 Cable tie 4

1587 Velcro cable tie 4 / 5
Elektro Skalar manual, German 1
Elektro Skalar manual, English 1
Elektro Skalar manual, French 1

Accessories:

Graupner

Order No.

Description Dimensions

[mm]

No. off

reqd./pack

1603 Flexible hook/loop tape 1
1665 Soft receiver padding 1
1602 Rotor blade support 1

1296 Main rotor blades, GRP, reflex 40 552x50 1 pair
1269 Main rotor blades, GRP, symmetrical 552x50 1 pair