Aviation Models 30% Extra 260 User manual

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Aviation Models
30% Extra 260 A s sembly Manual
For assistance contact :
Aviation Models
25022 104th Ave SE, Suite E
Kent, WA 98030
ProductInformation: 1 - 253 - 332 - 0786
OrderingHotline: 1 - 866 - 877 - 8621
Copyright © 2005 by Aviation Models, Inc. All rights reserved.
First edition rev. 6.05.29
please report errors to [email protected]

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WarrantyInformation:
Aviation Models, Inc. guarantees this kit to be free of defects in both material and
workmanship at the time of purchase. This warranty does not cove r any comp o nents
damaged by use or modification. In no case shall Aviation Models, Inc. liability e x-
ceed the orig i nal cost of the purchased kit .
Further, Aviation Models, Inc, r e serves the right to change or modify this warranty
without notice. In that Aviation Models has no control over final assembly or materi-
als used in final assembly, no liability shall be assumed or accepted for any damage
resulting from the use by user of the final user assembled product. By the act of using
the user assembled pro duct, the user accepts all resulting l i ability. The user should
check the aircraft for structural damage before each flying session and immediately
after any ground strike other than a soft landing. DO NOT AT TEMPT TO FLY AN
AIRCRAFT WITH ANY STRUCTURAL D AMAGE!
If the buyer is not prepared to accept the liability associated with the use of this pro d-
uct, the buyer is advised to return this kit immediately in new and unused con dition to
the place of pu r chase.
While this kit has been flight tested to exceed normal use, if the plane will be used for
extremely high stress flying such as racing or extreme aerobatics the modeler is r e-
sponsible for taking steps to reinforce the high stress points. If you do not feel confi-
dent to do this, seek advice from experie nced modelers.
T his model should never be operated in a manner that is not compliant with all of the
Academy of Model Aeronautics National Model Aircraft Safety Codes.
Read through this manual before starting constru c-
tion. It contains important warning s and i n structions
concerning the assembly and use of this model.
The pictures in this manual may be of airplanes with different covering schemes.
The planes pictured were of identical construction. Only the color schemes were
different.

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Warning. This is not a toy. If not properly con trolled it
can cause injury or death and prop erty damage.
Included Hardware: Aluminum spinner, fuel tank, aircraft grade aluminum
wing - tube, aluminum main gear, rubber wheels, tail wheel bracket, alum i-
num servo arms, alumi num stab tube for r e movable stab, control horns,
hinges, wheel pants, SAE bolts and nuts, much more.
Specifications:
Wingspan: 87"
Length: 75.5"
Flying Weight: 16lbs
Wing Area: 1411sq.in.
Engine Size: 50cc
CANISTER READY, COWL RING MOUNT, PRE - HINGE - SLOTTED SU R-
FACES,PUSH - RODS AND CONTROL LINKAGES INCLUDED, 5” POLISHED
SPINNER INCLUDED FUEL TANK, WHEELS, LANDING GEAR, MOUNTING
HARWARE, NUTS, BOLTS AND MORE – ALL INCLUDED
FULL PARTS SUPPORT IN STOCK
Additional equipment r e quired:
Computer Radio with at least 4 cha n nels
2 Elevator servos minimum 100 oz/in. of torque each
2 aileron servos, total torque required not less than 120 oz./in. per wing.
Rudder servo(s) at least 180 oz./in.
Throttle servo
Radio operated engine kil l switch or servo operated choke strongly su g gested
Single or dual radio battery packs at least 1650 mAh total
Switch[es]for receiver batteries
Miscellaneousservoextensions.
Flexing in linkage can and will cause flutter of the control surfaces which wi ll
destroy the airplane in just a few seconds. Metal gear se r vos are required.

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Table of Contents
Page Subject
5 Open and inspect ev e rything
6 Mount the engine
10 Hinge the control su r faces
12 Mount the hatch and canopy
13 Mount the horizontal stabili zers
13 Install the control horns
14 Install the elevator & aileron servos
16 Throttle and (optional) choke servo installation.
17 Install the landing gear
18 Mount the rudder servo and linkage
18 Install a fuel tank and fuel system
19 Prepare and Mou nt Cowl
20 Mount the wings
20 Final Checks
21 Check and adjust ba l ance
21 Control throws

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30% Extra 260 Assembly Manual
Step 1. Open and inspect everything
This section should be fairly self e x planatory.
In the large box you should have a f u selage w ith hatch., wing tube and dual stab
tubes, the elevator/stab asse m blies, the rudder, cowl, wheel pants, canopy, and a
package with the landing gear, tail wheel bracket and mi s cellaneous nuts and bolts.
Use some acetone on a rag to clean the glue off the tu bes. Under all of this is a
false floor, and under that you will find the wings with ailerons attached. The
hinges are installed in the elevators and ailerons
, but they are not glued, you
have to do that. The hinges for the rudder are in the hardware pack. We have had
good luck with Pro - bond Ultimate and Gorilla glue, both of which are glues that
expand as they dry cure and fill the voids in the hinges and their sockets.
Check everything for shipping da m age and/or manufacturing defects. If there is a
pro blem, report it to us NOW, not after you start building the plane.
Read the quick start guide at the end of this manual first. It has hel p ful hints
and any errata corrections that may be available.
Before proceeding to any assembly, now is a good time to go over the whole plane
and fix any cosmetic flaws. Some cosmetic flaws are to be expected, this fact is r e-
flected in the price.
Using This Manual
When you start a construction section, it is a good idea to first read that entire se c-
tion before cutting or drilling or glueing. For example, if you are about to begin
the section called “Mount the Hatch and Canopy”, then read that entire section b e-
fore doing anything else. Toward the end of that section, there is an option to paint
frame line on the inside of the canopy. If you’ve already glued it on, it will be im-
possible. Reading the entire section will give you a good feel of where you are
headed and any options available.

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Knownissuesandimprovements
There are a few areas where, at this unassembled stage, you can improve the final
results of your assembly pr o ject. There are many items that cannot be addressed on
the a s sembly line due to cost and possibly because not every improvement would
be welcomed by every builder. Here are a few items that h ave come up over time.
Go over the covering with a heat gun or iron
. The covering tends to get loose
over time and with changes in temperature and humidity. It may have come out of
the box with wri n kles, I can assure you it did not go into the box that way .
Clean out the hinge holes. Without removing any wood, use a very sharp X
- acto
knife and remove any covering that may have been pushed into the hinge holes. It
is very important that the glue sticks to the wood and not to the covering.
Lightweightlanding gear and wing tube. In the 30% EXTRA 260 we have tried
to provide as much flexibility as possible with regard to engine choice. It is som e-
times difficult to be all things to all people. In any case, we have provided very
strong landing gear and wing tubes, which are suitable for any type of engine and
flying but add some weight to the finished plane. Some pilots chose to order ca r-
bon f i ber landing gear and/or wing tubes. This can save several ounces of weight.
Hardening holes. The fuselage sides on this plane are made of balsa which in ce
r-
tain areas is doubled by lite - ply. Using wood screws in balsa is diff i cult because
balsa is very soft. It’s a good idea whenever you drill a hole that must accept a
wood screw to put a drop of thin CA into the hole and then if necessary re - drill the
hole. The CA will wick into the wood and harden it, adding strength in that area.
Engine mounting
PLEASE READ THE INSTRU C TIONS FOR STEP 2 COMPLETELY BEFORE
CUTTINGANYTHING!
The first thing to do, before anything else goes in the fuselage, is to get the engine
mounted and aligned with the cowl. This can be a little tricky, so take your time.
This is perhaps the most difficult part of building this kit, so once you get this
right, you’re on your way to having a great plane . Do this first before you hinge
the ru d der.
Note that the firewall already has a proper amount of right thrust built in, do not
use any other offsets. When you shim the engine out from the firewall use shims of
equal thickness on all 4 corners so that yo u do not introduce any other thrust a n-
gles.
This plane is designed around an e n gine of 3 to 4 1/2 pounds. If you plan to use a
heavier engine (some people plan to use 70 - 75cc, even though that is way ove r-
powered and overweight) it’s a good idea to double the firewall. I have flown this

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plane with a 60cc(4.0 lbs) on the front, and it had an insane amount of zip. With
HiTec 5945’s on the elevators, pull - pull ru d der, and the 4.0 lb. engine on the front,
the CG came out right on the factory recommendation without any batteries inside.
Sim ply place one battery right in front of the wing tube, and one right behind and
your CG will be very close. This is just a guide, each plane should be checked i n-
dividually.
We will prepare our engine box in four steps:
(1) Ca lculating the engine box length
(2) Cutting the engine box
(3) Marking and preparing our firewall
(4) Glue and re - enforce firewall
(1) Calculating the engine box length
{Engine Cowl length (plus) ¼” prop clearance} (minus) engine length = e n gineboxlength
To determine your engine cowl length, place the cowl on a flat counter and place a
straight edge across the top. With a rule, measure from the flat counter to the bo t-
tom of the straight edge.(see figure 1) Write this number down – it is your cowl
length(CL) . NOTE: The back mounting plate of your cowl is r e cessed ¼” from
the e p oxy - glass edge. Use a ¼” shim under your yardstick so that our zero point
is the back of the pl y wood mounting plate.
Measure your engine
from the rear of the mounting plate to the surface that the
rear of the prop will rest. (see figure 2) This is your e n gine length (EL)
Figure1 Figure2

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Now, let’s calculate the proper engine box length for your setup.
Cowllength (minus) eng inelength=engineboxlength
If you measure the sides of your e n gine box, you will see that they are different
lengths. This is because some right thrust is built in. Add the 2 measurements and
divide by 2 to get the length at the center.
E XAMPLE: one side measures 6 5/8”(starboard) and the other 6 7/8”(port). Our
average uncut engine box length would be (6 5/8” + 6 7/8”) / 2 = 6 3/4” If we use
the e x ample above and wanted our final engine box length to be 6 1/16”, then 6
3/4”(avg. orig inal length) – 6 1/16”(final length) = 11/16”. I would have to cut
11/16” from each of the e n gine box sides. By cutting both sides the same amount,
we do not change our thrust a n gle.
Now, let’s mark and prepare our fir e wall for engine mounting before w e glue it in
place.
First, remove your carburetor and trace your engine mounting plate.
EXAMPLE: CL = 11 3/4” EL = 5 15/16” so,
11.75
- 5.9 4
engine box = 5.81
now let’s add ¼” so our prop will _ .25
have a little clearance from the cowl 6.06
We would cut our engine box to be 6 1/16” long
After you trace it, cut it out and
then draw diagonals from hole
to hole. When you are done, it
should look similar to this:

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Next mark your firewall with center lines. Label the firewall “Top” and “front“
with a pencil. Now measure & mark the last line as shown.
The line that runs horizontally can be moved to accommodate your particular e n-
gine. However, the centerline of the crankshaft should be placed as close as poss i-
ble to the wing line extended. We are now ready to mark and drill our firewall for
our engine. Take the engine mount pattern you made in the last step and place it
over the firewall so that the center marks of the engine pattern line up with the new
centering mark on the fir e wall. Rotate until vertical. Use an ice pick or an awl to
push t hough the center of each of the 4 engine mounting holes. Make sure you
make the hole big enough to find later. When done, drill the firewall through each
awl mark with the appr o priate size bit for your engine mounting bolts. (10 - 32
hardened, socket head bolts and blind nuts will do nicely) Also use a hole saw or
jig saw to cut out the center until your carburetor passes through ea s ily.
We are now ready to epoxy the fir e wall into the engine box. BE SURE TO PUT
THE TOP AT THE TOP AND THE FRONT TO THE FRONT – as labeled in the
previous step. Wipe away excess epoxy. A large blob in the wrong place will pr e-
The ¼” of f-
set is to
counte r act
the right
thrust. This
willbring
the prop
shaftback
to the ce n-
ter of the
cowl as it
e x its.

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vent the proper fit of the triangular stock in the next step. After your wipe away
the excess, a little rubbing alcohol on a paper towel w ill finish the job nicely.
After you glue the firewall to the engine box sides,
rein force it with 1/2” triangle stock on the inside of the
fire wall - above and below mid - plate. Drill out the
center hole so that the carburetor passes easily through
the fire wall. If you want it to be super strong, bolt 2
small pieces of aluminum a n gle to the front (see
diagram).
Hinging
Like I said, the rest is very easy.
Hinging is a very simple matter. We recommend that you hinge all the control su r-
faces in two steps allowing the glue to dry between steps.
Before you start gluing anything, test fit each control surface. Aileron to wing, el e-
vator to stabilizer, rudder to fin/fuse, with the hinges in place. Make sure the
hinges go in the holes smoothly and that there i s ample room for the hinge
“knuckle” so there is no large gap between surfaces. The hinge lines are beveled.
The point of the bevel should be at the center of the hinge pin, this assures that the
hinges are aligned and ce n tered on the hinge line.
Once you are certain that they all go together smoothly, take one surface and r e-
move the hinges. If you have a needle oiler, place 1 or 2 drops of oil into the hinge
and work it back and forth. It’s also a good idea to put some lite oil (like WD40)
on a rag, and to wipe the edges of the hinging surfaces with this rag. The oily res i-

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due will keep spilled glue from stic k ing to the ultracote covering. Then wipe off
any excess oil from the su r face. Glue the hinges into the holes securely using the
glue yo u prefer. I have had good success with Pro - bond polyurethane (not the pro -
bond yellow furniture glue) because when dr y ing it foams up slightly and fills the
gaps b e tween the hinge and the mounting hole. Pacer Hinge glue works great for
the same reason.
M ake sure the bent hinge is able to go perpendicular to the edge (see pi c ture).
When the glue is dry, do the same thing with the mating surface, glue the hinge
legs into the holes provided. Keep the surfaces as close t o gether as possible to
minimi ze gaps. When completed it’s a good idea to seal the hinge gaps by ironing
a piece of Ultracoat covering material into the groove b e tween the surfaces.
Repeat this on both elevators and both ailerons. For the rudder you may wish to
wait until later to do the final i n stallation of the rudder, it makes it easier to handle
the ai r plane.
To make the rudder removable, it is possible to remove the hinge pin from each
hinge (grind off the recessed end and push the pivot out) and one or two piece of
wire as the pivot on all the hinges. Use the largest wire that will fit through the
hinge holes. Then to r e move the rudder you just remove the wire, but be sure the
wire can’t fall out in flight. I have used a very small wheel collar to retain the
hinge wire.

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Mounting the Hatch & Canopy
The hatch mounts to the fuselage by two
tabs on each side that are a t tachedat
the rear of the hatch. They are already
built into the hatch and should have 6 - 32
blind nuts mounted in them. Set the
hatch in place and check to see that the
6 - 32 bolts (supplied) thread ea s ily into
the blind nuts. You may have slightly
enlarge the holes in the fuse if the blind
nuts don’t line up perfectly. Check also
to see if the 2 dowels are protruding out
of the front at least ¼” – and th at they
are glued in s e curely. Once you are
satisfied, remove the hatch. We will now attach the canopy to the hatch. If there
is an air gap between the mounting tab and the inside of the fuselage side, you
may want to fill it with a piece of scrap plywo od. We have had a few incidences
of flyers over - tightening the mounting bolts until they broke or weakened the glue
joint on the mounting tabs. This r e sulted in the hatch flying off in flight – leaving
the mounting tabs still bolted in place.
With a Co vering Iron, touch - up any wrinkles in the Ultra - Cote covering where
your ca n opy will sit. Make sure the Ultra - Cote is stuck well to the balsa in this
area. Once the ca n opy is glued, you will not be able to get into this area. Carefully
trim the canopy to fit the hatch. Leave a small lip in the front, it makes the attac h-
ment more secure. Trial fit it several times until you are happy with it. Remem-
ber, you can always trim more off but it’s hard to put back on. Attach the ca nopy
with whatever is your favorite method. Some people use tape, some glue the ca n-
opy down, some use small screws. This is up to you. If you use small screws add
some hard wood such as 1/16” ply to back up the balsa wood of the hatch. I like
E- 6000 clear glue found at your local hob by store. If you use it, run a small
bead(1/8” diameter) all the way around the canopy. Holding the ca n opy by the
edges, open it slightly and carefully lower it into place. Use a few pieces of ele c-
trical tape to hold it in place overnight. Don’t worry about any E - 6000 that may
squeeze out. It is actually ea s ier to clean after it hardens. You can trim it carefully
with a sharp X - acto and roll it off.

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Install horizontal stab i lizer
Use a sharp hobby knife
to carefully trim the
cove r ing around the
ho les in the fuse for the
stab tube and the bolt
holes on each side. Slide
the aluminum
tube(supplied) through the fuse, and slide the stab i-
lizers onto the tubes from each side. Make sure that both stabs are snug against
fuse. Using the 6 - 32 allen bolts(supplied), attach the stabs to the fuse.
Install the Control Horns
Elevator Servo Insta l lation
Mount the provided control horns to each
control surface on the hard points. T ryand
get the control horn base as close to the
leading edge of the control su r face. This will
provide the proper geometry and allow the
control surface to move both dire c tions
equally. For the elevators, place each horn
1” from the fuse, and the exact s ame di s-
tance from the hinge line. Otherwise, the
geometry will be different and it will be diff i-
cult to adjust the throw amount to be equal
in both directions. (See di a grams below)
Stab
Elev a tor

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Aileron Servo Installation
Find the open servo bay on the left
and right side of the fuselage in the
tail. Remove covering. Attacha
servo extension to the servo cord
long enough to reach the receiver,
and tie this servo connector t o-
gether with de n tal floss or whatever
you prefer. Slide the exte n sion
through the servo hole and fish the
endthrough the fuse with a piece
of wire with a hook or whatever you
want to use. There is a channel
cut in the bo t tom each former. If
you run the e x tensionsthrough
these holes it keeps the wires from
flopping around in flight. Servos
should be s e cured with all screws.
Cut back the covering and i n stall
the rudder and elev a tor servos
onto the pre - installedhardwood
mounting rails.
Find the aileron servo bay in each
wing. Cut back the covering. There
is a string attached inside . Pull it
loose and use it to pu ll the servo
wire through the channel in the
wing. Once again, add a servo
wire extension if necessary and
secure. Install the servo onto the
pre - installed hard wood rails.
Mount the aileron control horn pe r-
pendicular to the servo arm in the
pre - installed hardwood moun t ing
base.
Hard Point
90*

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Mount the throttle servo in the
floor of the engine box. If you
wish to use a servo to control
your choke, you can mount it
similarly. Use 2 pieces of 1/16”
ply as doublers for the screws to
have some meat on bothse r-
vos.
If you wish to use a servo to control
your choke, you can cut the mid - plate
appropriately to drop in your servo.
Use 2 pieces of 1/16” ply as doublers
for the screws to have some meat .
The pros is that it give an added
measure of safety (e xtra kill method)
and is co n venient. The cons is that it
adds a little extra weight and may
slightly effect performance. Also a
little more battery drain. A mechan i-
cal choke is another option and is pi c-
tured.
The bellcrank and hardware for a
mechanical choke hookup is not pr o-
vided but can be purchased inexpe n-
sively at your local hobby shop.
Position the bell - crank so that the
pushrod exits the fuse about ¾” in
front of the landing gear notch. If you
use a canister muffler, this entire
linkage will have to be repositioned.

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Main Landing Gear Installation
Tail Wheel Install a tion
Using the four 8 - 32 X 1” long bolts
provided, and four 8 - 32 locknuts pr o-
vided. Mount the landing gear to the
main gear plate as shown in the pi c-
ture.
Use a 2.5 mm or 3/32” drill bit to drill 3
moun t ing holes.
Put a few dr ops of thin CA into the
holes to harden the wood.
Let it dry
.

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Rudder Control Horn Setup
Use three, 3x4mm self - tapping
screws to secure the tail wheel
bracket to the holes drilled in the
last step.
Using two 8 - 32x3/4” allen bolts,
run them through the gear and
through the holes in the pant.
Take a small square piece of
plywood and glue it to the inside
of the pant. Now take two 8 - 32
blind nuts and tighten the allen
bolts. Once the blind nuts are
tight add a small amount of glue
to the blind nuts to hold them in
place. Glue another piece of ply
to the opposite side of the pant to
catch the axel. This will pr o vide
some additional strength.
Mount the rudder control horn to the
rudder the same way as the elevators
and ailerons. Make sure that with full
up elevator y ou have plenty of clea r-
ance between the control horn and
the elevator. If you do not have the
proper clearance the elevator will hit
your pull - pull wire. Once your control
horn is mounted you can now install
the pull - pull wire. Make sure that the
wire goes straight to the rudder servo
in the fuse.

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Trim the cut - out in the center of
the ru d der servo tray to fit your
rudder servo.
Glue the stif feners to the bottom
of the ru d der servo tray.
The tray will fit approximately in
thisp o sition. You may want to
delay this process until you have
everything i n stalled & then move
this forward or aft in order to a d-
just CG.
Most will be able to glue it i n this
position and adjust CG with ba t-
tery plac e ment.
Cut 2 pieces of ¼” X ½” balsa stick 72
mm long each. Epoxy one on each
side of the fuse. These will fit under
the tray & between the stif f eners.
When the epoxy cures, trial fit the tray
by droppin g it onto the 2 rails. If ev e-
r y thing looks good, apply epoxy to the
top of the rails and position the tray.

19
Engine cooling and clearance
Run the pull - pull wires down the
fuselage, and make sure the c a-
bles are not rubbing on anythin g .
Attach the large aluminum servo
arm securely to an existing servo
wheel and attach cables with
hardware provid ed.
Cut out the cowl in the required spots
so you have plenty of clea r ance
around the muffler and cyli n der.
Also open up the box on the bottom of
the cowl in o r der to cool the engine
during flight. If you do not provide
enough exit for the air, the e n g inewill
overheat.
The installation of the tank (supplied)
and fuel lines is very straightforward.
Place a piece of foam under the tank
to prevent fuel foaming and strap it
with tie - wraps or Velcro.

20
Wing Mounting
Final Checks
Take a few minutes to re - check each servo to make sure all screws are in place and snug.
If you use metal gear servos(a good idea), place one drop of thread locker on the screws
that hold the arms on the servos. Re -c heck all control horns, and all linkage for slop or
looseness. This would greatly increase the chance of flutter and could destroy your ai r-
plane. This is a 3D/Aerobatic airplane with large surfaces. Be careful to keep everything
tight and control your s peed when flying.
Put on your prop and spinner. Put in all radio and batteries. Mount all switches & attach
all wiring. A s semble the airplane, we will now check the CG.
Once the cowl is ready to mount,
slide it onto the fuselage and attach
using6 - 32 bolts and washers pr o-
vided. Two screws go through the
fir e wall into the cowl ring – two go
through the ring into the firewall.
Blind - nuts are already installed to r e-
ceive them.
Mark the root rib of each wing 6 ½”
from the leading edge. Transfer the
mark to the underside of the wing. We
will use this measurement in a bit to
check our Center of Gravity (CG).
Use the supplied nylon mounting bolts
to attach the wing onto the f u selage.
Make sure that the wing bolts are in
place and snug before each flight to
prevent the wing from coming off du r-
ing flight.