Carf-Models SuperXtra 330L User manual

[email protected]
Composite-ARF SuperXtra 330L (3.1m span)
Instruction Manual
Composite-ARF SuperXtra 330L, 3.1m
TAVS Technology version 3.0

Composite-ARF SuperXtra 330L (3.1m span) Sheet 1
P15P14P13
P9 P12P10 P11
P8P7P6P5 P4P3P2P1
P16
VERSION3.0 MikeC(6September2005)Mac

Composite-ARF SuperXtra 330L (3.1m span) Sheet 2
P31P30P29
P25 P28P26 P27
P24P23P22P21 P20P19P18P17 P32
VERSION3.0MikeC(6September2005)Mac

Composite-ARF SuperXtra 330L (3.1m span) Sheet 3
P46 P47P45P44
P40 P43P41 P42
P39P38P37
P36P35P34P33
VERSION3.0MikeC(6September2005)Mac

Composite-ARF SuperXtra 330L (3.1m span) Sheet 4
P52 P53
P51P50P49P48
VERSION3.0 MikeC(6Septemeber2005)Mac
Carbonfibre landing
gear leg 120-125mm
Ø wheel
wheelpant
M6 bolthead
washer
6mm wheel
collar
washer
washer
M6 locknut
M6 nut
milled plywood
WHEELPANT X-Section
AILERON THROWS
low rate: 60mm down
high rate: 90mm down
high rate: 90mm up
low rate: 50mm up
RUDDER THROWS
high rate: 240mm (max.)
low rate: 70%
low rate: 70%
high rate: 240mm (max.)
ELEVATOR THROWS
high rate: 150mm (max.)
low rate: 60mm
low rate: 60mm
high rate: 150mm (max.)
3 - 3.5° depending on propeller
SIDETHRUST
C of G range: 110 - 130mm
from Leading Edge at Wing Tip.
CENTRE of GRAVITY

Instructions for Extra 330L IMAC-Airplane
Thank you very much for purchasing our Composite-ARF Extra 330L all composite aircraft, made
with the revolutionary Total Area Vacuum Sandwich (TAVS) technology.
This is a fully-updated Instruction manual showing the latest ‘Wing-tube’ version of the
SuperXtra, which replaces the ‘carbon blade-spar’ version that is not manufactured any more.
Some of the photos show the original version, where it is unchanged from the new ‘Tube’ ver-
sion - so please don’t get confused!
Before you get started building and setting-up your aircraft, please make sure you have read this
instruction manual several times, and understood it. If you have any questions, please don’t
hesitate to contact us. Below are the contact details:
Email: [email protected]
or [email protected]
Telephone: Phone your C-ARF Rep!!! He will be there for you.
Website: http://www.composite-arf.com
This instruction manual aims to do 3 things:
1) Show you how to build your aircraft accurately and properly.
2) To explain about your fully-composite aircraft, and how to handle and maintain it.
3) How to set up and trim your finished IMAC type aircraft perfectly to give you the most enjoy-
ment from it.
Below are a few of the TOC pilots who helped to design and modify our 3m Extra 330S to the
championship-winning standard it is now at. And your 2.6m span Extra 330L is based on the
design of that plane and the experience of these experts.
Composite-ARF SuperXtra 330L (3.1m span) [email protected]
2
Jason Shulman
Sebastiano Silvestri
Ivan Kristensen
Mike McConville
Composite-ARF
would like to thank all of
these 4 very experienced
pilots for their co-operation and
help, which has made this 330 Extra
aeroplane as good as it is today.
Of course all four of them are also Rep’s for
C-ARF, and if you want to ask them any questions
you can email them (see our website for links) directly,
or email your questions to us at ‘feedback@composite-
arf.com’ and we will forward your comments to them.
We are sure that they will answer you right away.

Liability Exclusion and Damages
You have acquired a kit, which can be assembled into a fully working R/C model when fitted out
with suitable accessories, as described in the instruction manual with the kit.
However, as manufacturers, we at Composite-ARF are not in a position to influence the way you
build and operate your model, and we have no control over the methods you use to 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
application 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 Composite-ARF compa-
ny to pay compensation is excluded, regardless of the legal argument employed.
This applies to personal injury, death, damage to buildings, loss of turnover and business,
interruption of business or other direct and indirect consequent damages. In all circumstances
our total liability is limited to the amount which you actually paid for this model.
BY OPERATING THIS MODEL YOU ASSUME FULL RESPONSIBILITY FOR YOUR ACTIONS.
It is important to understand that Composite-ARF Co., Ltd, is unable to monitor whether you
follow the instructions contained in this instruction manual regarding the construction, operation
and maintenance of the aircraft, nor whether you install and use the radio control system
correctly. For this reason we at Composite-ARF are unable to guarantee or provide a
contractual agreement with any individual or company that the model you have made will
function correctly and safely. You, as operator of the model, must rely upon your own expertise
and judgement in acquiring and operating this model.
Supplementary Safety Notes
Pre-flight checking:
Before every session check that all the model’s working systems function correctly, and be sure
to carry out a range check.
The first time you fly any new model aircraft we strongly recommend that you enlist the help of
an experienced modeller to help you check the model and offer advice while you are flying. He
should be capable of detecting potential weak points and errors.
Be certain to keep to the recommended CG position and control surface travels. If adjustments
are required, carry them out before operating the model.
Be aware of any instructions and warnings of other manufacturers, whose product(s) you use to
fly this particular aircraft, especially engines and radio equipment.
Please don’t ignore our warnings, or those provided by other manufacturers. They refer to things
and processes which, if ignored, could result in permanent damage or fatal injury.
Composite-ARF SuperXtra 330L (3.1m span) [email protected]
3

Composite-ARF SuperXtra 330L (3.1m span) [email protected]
4
Attention !
This IMAC-Aircraft is a high-end product and can create an enormous risk for both pilot and
spectators, if not handled with care, and used according to the instructions. Make sure that you
operate your Extra according to the AMA rules, or those laws and regulations governing the
model flying in the country of use.
The engine, servos and control surfaces have to be attached properly. Please use only the
recommended engines, servos, propellers, and the accessories supplied in the kit.
Make sure that the ‘Centre of Gravity’ is located in the recommended place. Use the nose heavy
end of the CG range for your first flights, before you start moving the CG back to a more critical
position for 3D-manoeuvres. If you find that you need to relocate your batteries or even add
weight in the aircraft to move the CG to the recommended position, please do so and don’t try
to save weight or hassle. A tail heavy plane, in a first flight, can be an enormous danger for you
and all spectators. Fix any weights, and heavy items like batteries, very securely to the plane.
Make sure that the plane is secured properly
when you start up the engine. Have at least 2
helpers hold your plane from the tail end or
from behind the wing tips before you start the
engine. Make sure that all spectators are
behind, or far in front, of the aircraft when
running up the engine.
Make sure that you range check your R/C
system thoroughly before the first flight. It is
absolutely necessary to range check your
complete R/C installation first WITHOUT the
engine running. Leave the transmitter antenna
retracted, and check the distance you can walk
before ‘fail-safe’ occurs. Then start up the engine, run it at about half throttle and repeat this
range check with the engine running. Make sure that there is no range reduction before ‘fail-safe’
occurs. Only then make the 1st flight. If you feel that the range with engine running is less then
with the engine off, please contact the radio supplier and the engine manufacturer and DON’T
FLY at that time.
Check for vibrations through the whole throttle range. The engine should run smoothly with no
unusual vibration. If you think that there are any excessive vibrations at any engine rpm’s, DON’T
FLY at this time and check your engine, spinner and propeller for proper balancing. The light-
weight sandwich composite parts don’t like too much vibration and they can suffer damage. The
low mass of all the parts results in a low physical inertia, so that any excess vibrations can affect
the servos and linkages.
Make sure that your main spar tube is not damaged. Check that the front and rear anti-rotation
pins for the wings and horizontal stabiliser are located correctly in their holes, and are not loose.
Check that the 4 plastic wing retaining nuts are tight, that the M3 bolts retaining the horizontal
stablisers on to the aluminium tube are installed and tight, and that the hinge wires for the rud-
der and elevators cannot come out.
If you carefully checked all the points above and followed our advice exactly, you will have a safe
and successful first flight - and many hours of pleasure with your Composite-ARF Extra 330L.
NO !!!
Secure the plane
before starting the engine.
DANGER ZONES
NO NO

General information about
fully-composite aircraft structure and design
All the parts are produced in negative molds, manufactured
using vacuum-bagged sandwich construction technology.
All parts are painted in the moulds, either single colour or
designer colour schemes. A new production method, called
TAVS (Total Area Vacuum Sandwich), enables us to pres-
ent this aircraft with incredible built-in strength, while still
being lightweight, and for a price that nobody could even
consider some years ago. This production process has
huge advantages, but a few disadvantages as well. These
facts need to be explained in advance for your better under-
standing.
Description of Parts
The Wings:
Both wing halves are made in negative moulds, and fully
vacuum bagged, using only 2 layers of 2 oz. cloth in com-
bination with a very hard 2 mm foam sandwich form a hard
and durable outer skin. Because of this TAVS technology
very few additional structural parts are needed except for
main spars.
The ailerons are hinged already for you. They are laminat-
ed in the wing mould and are attached to the main wing
with a special nylon hinge-cloth, sandwiched between the
outer skin and the foam. This nylon hinge is 100% safe and
durable. You will never have to worry about breaking it, or
wearing it out. There is no gap at all on the top wing sur-
face, and there is a very narrow slot in the bottom surface,
where the aileron slides under the main wing skin during
down throw. This hinge setup is the cleanest you can ever
obtain, but you have to take some care during assembly for
proper installation and servo set up.
First, the hinge line is on the top surface of the wing, not in the centre. This is NOT a disadvan-
tage, if you set in about 10% NEGATIVE aileron differential in your transmitter program. This
means that the ‘down’ throw needs to be about 10% more than the up throw.
Why? Because the axis of the hinge is not at the centreline of the aileron, so it moves slightly
in and out when it travels, and the aileron gets a little "bigger" in surface area when moving up,
and "smaller" when moving down. This is why you have to set the negative differential in your
transmitter to compensate for the size changing. 10% is a good starting point, and you will find
out the exact setting during the first flights, doing fast vertical rolls and watching the fuselage
rolling in a perfect line. You can set it perfectly, this is guaranteed.
The bottom slot needs some explanation, too. The cut line is exactly in the correct position so
that the aileron slides under the wing skin smoothly. If the cut was a few mm forward or back, it
Composite-ARF SuperXtra 330L (3.1m span) [email protected]
5
Centreline of hinge axis
Phenolic control horn
The internal structure of the new
SuperXtra wing, before the carbon
reinforcement & rovings are added
above & below the spar during the
joining process.

would not work properly. So, make sure that the lip is not damaged, and that the aileron slides
under this lip perfectly. It will NOT lock at any time, as long as the lip is not damaged. If damage
occurs to the lip, you can cut off 2-3 mm, but you should NEVER need to cut off more than this.
The wings are already set-up for 2 servos per aileron, and designed specifically around a pair of
JR/Graupner 8511/8611 servos which fit into a CNC-milled phenolic plate. For normal pattern
style flying, a pair of JR8411, or equivalent, servos should be sufficient, but we highly recom-
mend that you use the suggested 8511/8611servos.
The wings are attached to the fuselage with the 4 threaded aluminium dowel anti-rotation pins,
with big 4 plastic nuts inside the fuselage. If the aluminium dowels come loose in the wing, the
wing will slide outwards, away from the fuselage, and the main spar tube will definitely break. So
take great care to inspect the glue joints of these anti-rotation dowels in the wing REGULARLY.
Excessive vibrations or hard shocks can cause the glue joints to weaken or break. Monitor these
joints whenever you set up your plane. Never forget to tighten the nuts inside the fuselage. Your
flight will end after 100 ft and you will have to fix a hole in your club’s runway. Please DO NOT
modify these attachment dowels in any way, their perfect function is proven for many years.
The Fuselage:
The fuselage is also made in negative moulds, and (except for the bottom surface) it is also all
constructed using TAVS technology, with the diagon-technique carbon strengthening for
improved torsional stability. All the loadbearing internal parts are glued in during manufacture, to
ensure accurate location and reduce the assembly time for you. The fibreglass tubes in the wings
and fuselage to receive the wing tube spar, the stab spar tubes, and the holes and reinforcement
plates for the anti-rotation dowels, are already installed.
The landing gear mount is strong and does-
n’t need any extra reinforcement. You have
an extremely light weight fuselage, and the
gear loads need to be led into the structure
gently. No glue joint needs to be stronger
than the materials that it is attached to, as it
would just result in increased weight for no
advantage. The landing gear is a fairly flexi-
ble design, which works very much like
shock absorbers. This plane is not made for
crashing, but the landing gear will take some
hard landings without problems. Do not
change or modify it, as the results would only
be negative. We had plenty of time and experi-
ence to engineer the strength needed in this
area - and we did !
The motordome and firewall are pre-installed, and provide plenty of strength for any engines up
to 150cc on the market today. See the Engine Installation section for details of engine and set-
ting thrust angles.
The engine cowling should be attached using the method shown. It is only a little work and this
mounting has been tested and proven for many years.
Composite-ARF SuperXtra 330L (3.1m span) [email protected]
6
(above) The fuselage is manufactured using the
‘Diagon-technique’ with carbon tows to give
exceptional torsional stiffness combined with
extremely low weight.

The Stabilisers:
The stab parts are also vacuum bagged sandwiched. The
rudder and elevator control surfaces are hinged with 4mm
Ø tubes, fitted through phenolic hinge bearing plates which
are installed during manufacture for perfect alignment.
All the structural parts are pre-installed. The horizontal
stabs are mounted with one 20mm tube and a carbon rod
anti-rotation pin each. The rudder & elevator design allows
for at least 50 degrees throw. For the SuperXtra it is neces-
sary to keep the tail area as lightweight as possible, but it is
still mandatory that each stab is fitted with two powerful dig-
ital servos (JR8411 or 8511/8611) installed in each half.
Please remember during assembly that every gram of
weight should be saved in the tail area, without omitting our
recommendations about mass-balancing of the elevators.
Servo Screws:
Fix the all the servos into the milled plywood servo mounts
using the 2.9 Ø x13mm sheet metal screws provided in
the kit, not the standard screws normally supplied with
servos by the servo manufacturer. This is because all the
holes in our milled servo mounts are 2mm diameter, due
to our CNC manufacturing process, and this is too big for
the normal screws.
Take Care:
Composite sandwich parts are extremely strong, but frag-
ile at the same time. Always keep in mind that these con-
test airplanes are designed for minimum weight and max-
imum strength in flight. Please take care of it, especially
when it is being transported, to make sure that none of the
critical parts and linkages are damaged. Always handle
your airplane with great care, especially on
the ground and during transport, so you will
have many hours of pleasure with it.
Composite-ARF SuperXtra 330L (3.1m span) [email protected]
7
(below) The SuperXtra is 95% pre-
fabricated, with all the main bulk-
heads, tuned-pipe supports, car-
bon bracing etc, installed at the
factory. Below is a general view of
the cockpit, muffler mounts and
R/C gear area - as it is shipped.
Some views inside the new factory,
showing a small part of the ‘Finishing’ and
the ‘Quality Control/Assembly’ areas.

The ‘Paint Job’
Occasionally customers notice certain problem areas with composite parts.
But the question is: Are these real problems, or are they just a misunderstood sign of high-tech
construction, proving the high-end composite technology?
Seams:
ALL composite parts have seams.
They are there today, and they will
be there forever. You will have to get
used to them ... or you’ll have to
touch up the paint yourself !
But what is a seam? A seam on the
fuselage, especially already painted
in the mould, proves that this is a
vacuum-bagged high-tech part,
made in negative moulds. Our
seams are fine and straight, no neg-
ative impression at all ... but they are
there. When possible we include
5mm wide strips of self-adhesive
vinyl, painted in exactly the same
colour as the plane for you to cover
the seams if you want.
Paint flaws:
If the aircraft is painted in the
moulds, you can save a lot of
weight. At least 2 lbs ... and that is
definitely worth saving !
A negative paint job is very compli-
cated to make. The painter never
sees the result of his job. He cannot
see the design growing and devel-
oping - he is painting ‘blind’. He
even cannot see little mistakes and
flaws, and even if he COULD, he
could not correct them. The maxi-
mum time to apply a designer paint
scheme in the mould is no more
than 20 minutes. It is a big rush
against time, because even if it is
just few minutes too slow then the
masking cannot be removed without
pulling off the paint itself ! This is a
BIG challenge, but the result is
extraordinarily impressive. Even
with slight flaws the general appear-
ance of these one-of-a-kind paint
Composite-ARF SuperXtra 330L (3.1m span) [email protected]
8
(above) The 3.1m SuperXtra, 2.6m Extra 330L and the
2.3m Extra, are also available in the ‘JR scheme’.
(below) One of our customers with our original
3m Extra 330S practising his tail-in hovering !

jobs is unique.
In a ‘positive’ paint job some effects can
never be done. Just think about the
shadows, peel backs, highlights, and
3D effects - and all with a perfectly flat
and uniform surface for optimum airflow
and aerodynamics.
Truly hard to do, but still possible, are
the paint jobs which seem to be so sim-
ple at first glance: Schemes with
straight lines and stripes. Quite easy
with positive painting, but it’s very hard
masking the lines in the negative
moulds, because we cannot assemble
the parts before masking. To get the
stripes lining up exactly at the rudder,
wing and cowling joints is therefore
almost impossible. This is why we sug-
gest using thin vinyl trim to make sure
that these stripes line up perfectly.
Sometimes it is necessary to do that,
and it is definitely not a quality problem
or a "flaw". It comes back to
what is possible, and what
is impossible.
If you want to have a really
perfect paint job, then you
might decide to have a sin-
gle colour version and have
it painted by yourself or
your friend.
But don’t forget: Consider
the additional cost, consid-
er the additional weight,
consider that even if it is
painted ‘positive’ there will
be areas you won’t be
happy with.
Of course you won’t com-
plain, because you created these flaws yourself… !
Composite-ARF SuperXtra 330L (3.1m span) [email protected]
9
(above) The complex paintwork is completed in the
moulds by our skilled staff, to produce such stunning
schemes as this, all with a perfectly flat surface.
(below) This is the FiberClassics (now ‘Composite-
ARF’) force at the TOC 2000, with all models painted
in the moulds.

Tools and Adhesives
Tools etc:
This is a very quick and easy plane to build, not requiring difficult techniques or special equip-
ment, but even the building of Composite-ARF aircraft requires some suitable tools! You will
probably have all these tools in your workshop anyway, but if not, they are available in all good
hobby shops, or hardware stores like "Home Depot" or similar.
1. Sharp knife (X-Acto or similar)
2. Allen key set (metric) 2.5mm, 3mm, 4mm & 5mm.
3. Sharp scissors
4. Pliers (various types)
5. Wrenches (metric)
6. Slotted and Phillips screwdrivers (various sizes)
7. M3 tapping tool (metric)
8. Drills of various sizes
9. Small spirit level, or incidence meter.
10. Dremel tool (or Proxxon, or similar) with cutting discs, sanding tools and mills.
11. Sandpaper (various grits), or Permagrit sanding tools (high quality).
12. Carpet, bubble wrap or soft cloth to cover your work bench (most important !)
13. Car wax polish (clear)
14. Paper masking tape
15. Denaturised alcohol, or similar (for cleaning joints before gluing)
Adhesives:
Not all types of glues are suited to working with composite parts. Here is a selection of what we
normally use, and what we can truly recommend. Please don’t use inferior quality glues - you will
end up with an inferior quality plane, that is not so strong or safe.
1. CA-Glue ‘Thin’ and ‘Thick’ types. We recommend ZAP, as this is a very high quality.
2. ZAP-O or PlastiZAP, odourless (for gluing in the clear canopy)
3. 5 minute-epoxy (highest quality seems to be Z-Poxy)
4. 30 minute epoxy (stressed joints must be glued with 30 min and NOT 5 min epoxy).
5. Epoxy laminating resin (12 - 24 hr cure) with hardener.
6. Milled glass fibre, for adding to slow epoxy for strong joints.
7. Microballoons, for adding to slow epoxy for lightweight filling.
At Composite-ARF we try our best to offer you a high quality kit, combined with outstanding
value-for-money, and as complete as possible. However, if you feel that some additional or dif-
ferent hardware should be included, please feel free to let us know.
Email us: [email protected]. We know that even good things can be made better !
Composite-ARF SuperXtra 330L (3.1m span) [email protected]
10

Composite-ARF SuperXtra 330L (3.1m span) [email protected]
Accessories
Here is a list of the things you may need to get your Composite-ARF Extra 330L in the air. Some
of them are mandatory, some of them can be chosen by you. What we list here are highly
recommended parts, and have been thoroughly tested.
1. Power servos (min. 12 required). We recommend JR8511/8611’s for ailerons, and
JR/Graupner 8411 or 8511/8611 for the elevators & rudder. An alternative is Futaba S9351.
2. Throttle servo (1) Any standard servo will do (eg: JR/Graupner 4041)
3. Aluminium Spinner 125 mm dia (5”), eg: Tru-Turn.
4. Main wheels 120 - 125 mm (4.5 - 5"). Kavan Light or Dubro wheels are recommended.
5. Engine DA-150. This is the recommended engine for your SuperXtra. The instructions
refer to that engine several times, but you could use any other 150cc engine.
6. Mini-Pipe Muffler Set. (Consists of 2 canisters, 2 aluminium headers, 2 Teflon couplers,
4 spring clamps, and mounting hardware).
7. Standard exhaust muffler. (optional, if noise is not a problem at your field)
8. High quality heavy-duty servo extension cables, with gold connectors. High quality
receiver and ignition switches, ‘Y’ leads, ceramic/ferrite chokes etc.
9. Receiver battery. 2 x 2400 - 2800 mAH 5-cell packs recommended.
10. Ignition switch and battery for motor. 4 cell 1400 - 1800 mAH recommended.
11. Powerbox 40/24 and dual powerswitches for Rx batteries.
12. Fuel tank (1500 ml) with gasoline stopper. We used a Dubro S-50 in this model .
13. Cable ties in various lengths.
14. Propeller. Carbon 32 x 10 or 32 x 12 Meijzlik or Menz.
About the ‘New’ 3.1m SuperXtra
The ‘new’ version of our SuperXtra has reverted to the proven 50mm wing tube for several good
reasons. It is an overall lighter design, the wings are easier to assemble at the field, and it’s eas-
ier to transport and ship. Furthermore we have now omitted the wing and stab incidence
adjusters - because everyone discovered that there is only ONE best setting for the plane !
Finally we have added the option for a 3rd aileron servo in each wing - for extra ‘snap ‘response.
The level of prefabrication is still carried to the limit. Canopy frame mounting, control surface
horns, servo mounts, etc., are all completed, aligned and checked, or pre-assembled, at the fac-
tory ready for your gear installation. Reacting to customer feedback, we have updated the hard-
ware pack, and now do not install the main fuel tank support/main-board and rudder servo tray,
to give you the option on position to suit your layout. Of course, these parts are all milled from
carbon composite and included in the kit for you to install wherever you want.
Did you read the warnings above, and understand the instructions completely?
Then, and only then, let’s start assembling your Composite-ARF Extra 330L.
If not, please read again before you start the assembly...
11

Building Instructions
General Tips:
We recommend that you follow the order of construction shown in this manual for the fuselage,
as it makes access to everything easier and saves time in the end. The wings and stabs can be
done at almost any point, and only need servos installing anyway, as we have already installed
all the control-surface horns for you at the factory.
The first thing to do is protect the finished paint on the outside of the model from scratches and
dents during building - so cover your work table with a piece of soft carpet, cloth or bubble-plas-
tic. The best way to stop small spots of glue getting stuck to the outside of the fuselage is to give
the whole model 2 good coats of clear car wax first, but of course you must be sure to remove
this 100% properly before adding any decals or markings. If you prefer you can cover the major-
ity of the fuselage with the bubble-plastic used to pack your model for shipping, fixed with paper
masking tape, which also protects it very well.
When sanding any areas of the inside of the fuselage to prepare the surface for gluing some-
thing onto it, do NOT sand right through the layer of glasscloth on the inside foam sandwich !
It is only necessary to rough up the surface, with 60/80 grit or equivalent, and wipe off any dust
with alcohol (or similar) before gluing to make a perfect joint.
Before starting construction it is a good idea to check inside the fuselage for any loose glass
fibres that could cut your hands, and a quick scuff over any of these with a coarse Scotchbrite
pad will remove them.
Note: It is very important to prepare the inside of the fuselage properly, by roughing up and
cleaning the surface, before gluing any parts to it.
Landing Gear Finished in 2 hours
The 1st job is to fit the landing gear legs and you can leave
these in place, as they will protect the bottom of the fuse-
lage during assembly. Wheel pants assembly can be done
later, but is shown here.
Composite-ARF developed a new carbon fibre landing gear
for the Extra. It consists of 45 deg laminated carbon fibre
cloth and a huge number of carbon tows inside, all made
under vacuum and heat-cured. However it is still light
weight, and retains enough flexibility to take the shock out
of any landings that are less-than-perfect!
To make it easy to replace or maintain the landing gear, the
undercarriage fixing bolts are installed from the outside,
bottom, of the fuselage, as shown in the photo here.
Mark the centreline on each landing gear, and drill 3 holes
with a sharp 6.5mm Ø drill as shown in the photo. The cen-
tres of the holes are measured from the bend in the leg that
will be flush with the outside of the fuselage.
Composite-ARF SuperXtra 330L (3.1m span) [email protected]
12
(above) The main legs are bolted
in place through the bottom of
the fuselage with 6 x M6 bolts.

The outer 2 holes are 33mm(1 5/16”) from the bend, and
the inner hole is 127mm (2 5/16”) from the bend. Note that
they are not equally position either side of the centreline.
The dimensions of 28mm and 8mm are measured from the
front of the carbon landing gear leg.
Fix the legs into the plane with the M6 x 20 bolts and 13mm
Ø washers into the blind nuts that are installed during man-
ufacture. Both main legs are identical, before you have
drilled the mounting holes, and can be used either side.
Fit the wheelpants to the legs as follows: Set the fuselage
on a level surface with the tailwheel in place. Pack the bot-
tom of the landing gear legs up by about half the diameter
of the wheels used (approx. 50mm/ 2”). Rough sand the
bottom of the carbon legs where the milled plywood parts
will be glued, to ensure a good bond. Fit the 2 plywood
pieces to the legs, using an M6 bolt and nut to hold loose-
ly in place. Hold the wheelpants against the milled plywood
pieces and adjust the angle of the plywood parts so that
they fit into the recesses in the moulded wheelpants, and
the bottom of the wheelpants are parallel to the ground and
each other. Tack glue the milled plywood parts to the bot-
tom of the legs with a drop of CA. Then glue the plywood
parts to the legs properly with slow epoxy and milled fibre.
To keep the wheelpants at exactly the correct angle and
flush against the milled plywood part that is glued to the
carbon leg, glue a small square (approx. 15mm x 15mm) of
scrap 3mm plywood inside the wheel pant 25mm above the
axle hole and glue an M3 blind nut to it. Then secure the
mainleg to the wheel pant by using an M3 bolt through the
leg. Do not use a bolt larger than M3, as the larger diame-
ter hole in the leg can weaken it.
The wheel axles are M6 x 70mm hardened steel bolts, fit-
ted through 6mm holes that you need to drill in the bottom
of the landing legs. Use the small dimple moulded into the
legs for the exact location. The head of the bolt goes on the
outside of the wheel, inside the wheel pant. The order of the
items on the bolt is: Bolthead, washer, wheel hub, washer,
6mm wheel collar, M6 nut, washer, carbon landing gear leg,
and finally another washer and the locking nut.
You may need to adjust the thickness of the wheel collar, or
add a couple of extra washers to get the wheel exactly cen-
tred in the wheel pant. A drop of loctite on the M6 lock-nut
is good insurance.
It is just possible to assemble all the spacing washers on
the axle and wheel and squeeze it all into the wheelpant
carefully, but it is far easier to drill an 9mm (approx.3/8”) Ø
hole in the outside of the wheelpant (directly opposite the
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(above) Shows scrap 3mm ply-
wood plate and M3 blindnut fitted
inside wheelpant.
(below) View of leg showing M3
bolt and M6 axle bolt with locknut.
(above) Milled plywood part glued
to carbon landing gear leg.

hole for the axle on the inner face) and
insert the axle bolt through this hole.
The order of fitting the wheelcollar, wash-
ers and wheel onto the axle, to centre
the wheel in the wheelpant, is shown in
the diagram here - but of course may
vary slightly depending on the size and
type of wheel used.
You can use any 4.5” - 5" main wheels.
Kavan wheels are very lightweight, but
not very durable on asphalt runways, and
Dubro wheels are a little heavier but
much more solid.
Any standard tailwheel assembly from a
good hobby store is suitable for your
Extra. The tail wheel setup shown in these photos is an
optional part available from C-ARF, and is mounted with 4
sheet metal screws and 2 plastic ‘U’ brackets under the
fuselage, screwed into the plywood reinforcement installed
in the fuselage at the factory.
You do not need to make the tailwheel steerable, a simple
castoring action is fine. However, for asphalt runways you
may prefer to connect it to the rudder horn with 2 springs as
shown. It’s easy to make these by winding some 0.8mm or
1.0mm Ø piano wire around a 5mm drill bit, turned slowly in
a battery-drill, with a small hook in each end to connect to
the tailwheel steering arms and the rudder horn.
Remember - keep it lightweight at the tail end!
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(above/below) Optional tailwheel
assembly from Composite-ARF.
Carbonfibre landing
gear leg 120-125mm
Ø wheel
wheelpant
M6 bolthead
washer
6mm wheel
collar
washer
washer
M6 locknut
M6 nut
milled plywood
WHEELPANT X-Section

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Cowling Finished in 2 hours
Attaching the 2 piece cowling is quite easy, as it is already
cut and trimmed at the factory, and should need almost no
adjustment for a perfect fit.
Sand the inside surface of both side (horizontal) flanges to
ensure a good gluing surface, and glue the 8 small pieces
(size 10 x 20mm) of 3mm milled plywood onto the flanges
of the bottom part of the cowling (4 each side), spaced
equally from the back to the front (see photos). The front
edge of the front piece should be 35mm (1.5”) from the
front of the cowl to clear the end of the mounting flange.
You can tack them in place with thick CA, and then rein-
force with 30 minute epoxy and microballoons mix.
Then take the bottom half and drill 3mm holes through the
dimple in either side, which match up with the dimple on the
fuselage, which also need to be drilled 3mm Ø. Do the
same by drilling the 2 holes in the back edges of the top half
of the cowling also, in the marks/dimples that are moulded
in. Temporarily bolt the bottom and top halves in place on
the fuselage with two M3 bolts and blind nuts on the inside
(inverted), and check for good fit. Tape the rest of the bot-
tom and top halves firmly in place, ensuring a flush fit with
the fuselage, and no gaps. If necessary you can sand the
inside back edges of both halves of the cowling to have a
perfect flush fit with the fuselage.
Now check the fit of the overlaps of the 2 halves of the
cowling, and sand the inside edges a little if needed for a
flush fit. When happy, tape together firmly and drill through
the joining flanges into the 8 plywood pieces, and secure
with 2.2mm ø x 10mm sheetmetal screws provided. The
holes for these small screws should be exactly 5mm from
the bottom edge of the top half of the cowling. The rearmost
2 screws will need to be shortened after fitting, otherwise
they will touch the motor dome. Just cut them off flush with
the inside of the plywood pieces.
The cowling is retained on the fuselage with 9 bolts M3 x
12mm and blind nuts. Drill one 3mm diameter hole at the
top/centreline of the cowl, approx. 10mm from the back
edge of the cowling, and insert an M3 x 12mm bolt and then
glue an M3 blind nut inside the fuselage with one drop of
thick CA glue. Don’t forget to rough up the area inside the
fuselage with coarse sandpaper first to ensure a good glue
bond. Note that the blind nuts are fitted reversed, with the
spikes pointing inwards! Check alignment again, and then
drill and fit the other 6 bolts in the same way, securing the
blind nuts to the inside of the fuselage with a single drop of
thick CA. Don’t forget to wax, or oil, the M3 bolts first, to
15
(above and below) Drill the
moulded-in marks in the fuselage
and both cowling halves and retain
with M3 bolts to ensure perfect
alignment.

make sure that you don’t accidentally glue any of the bolts
to the cowling or into the blind nuts! Space the bolts about
125mm (5”) apart, so that the lowest 2 bolts will be about
35mm from the edges off the square cutout in the bottom of
the cowling, which retains it properly.
Finally remove all the bolts and cowling, and glue the 9
blind nuts in place properly using a thick mixture of 30
minute epoxy and micro-balloons, as shown here.
Cockpit Canopy Finished in 1 hour
The canopy frame mounting has already been completed at the factory for you. It is held in place
with 4 bolts (M4 x 12mm) and and the holes are counter-bored so that the bolt-heads sit flush
with the fuselage surface. Fitting the clear canopy into the frame is a little bit tricky, but this is a
step by step guide of how to do it successfully:
Sand the inside edges of the canopy frame carefully with rough sandpaper, to ensure a perfect
fit of the canopy inside. Lay the canopy on top of the frame, and mark the rough shape with a
felt pen or wax crayon. Cut the outer border of the clear canopy with sharp scissors, about 12mm
(1/2”) too big all around. Unless you are in a very warm
room, we recommend that the canopy is slightly warmed up
with a hair dryer to prevent cracking - but be careful not to
melt or deform it! When the canopy fits inside the frame
roughly, mark the final cut line on it. Then cut it to exact
shape with a 6 - 8 mm overlap all around.
Make several hand-holds with wide paper masking tape
(see photo) to make holding and positioning the canopy
easy. Push the canopy up tightly inside the back of the
frame and fix the bottom 2 back corners with one drop of
slow CA each (ZAP-O or Plasti-ZAP recommended).
Note: Do NOT use any CA accelerator/kicker - you will
immediately ‘fog’ the clear canopy!
Tape the front of the canopy to the frame temporarily.
Mount the canopy frame to the fuselage (use all 4 bolts),
and tape the back of the canopy frame tightly to the fuse-
lage. Using the masking tape handles to pull the canopy
outwards firmly against the frame, working from the back
towards the front, glue the edges of the canopy in place in
2 more places each side, with just a single small drop of CA
at each position, all the time checking that the edge of the
canopy is tight up against the frame at the front.
Then make visual check from the front and back to make
sure sure that the canopy is straight. Now that the canopy
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(above) Counterbore the 4 holes
for the canopy frame bolts so that
the heads sit against the plywood
plates in the fuselage.
(above) The canopy frame is held
onto the fuselage with 4 plywood
tongues and M3 bolts/blind nuts.
Notice canopy finally glued in with
epoxy and microballoons mixture.
(above) M3 blind nuts, fitted
reversed, and fixed with thick
epoxy and micro-balloons mixture
inside the motor dome.