40% Extra 330L PAK Specifications

40% Extra 330L PAK Specifications
3.1m & 3.2m Extra 300 / 330 Kit
Builders Guide
Please read through the entire manual first. It contains important instructions and
warnings concerning the finishing of the model.
Jtec Radiowave guarantees this kit to be free from defects in both material
and workmanship at the date of purchase. This warranty does not cover any
component parts damaged by use or modification. In no case shall
Radiowaves’ liability exceed the original cost of the purchased kit. Further,
Radiowave reserves the right to change or modify this warranty without
In that Radiowave has no control over the final assembly or material used for
final assembly, no liability shall be assumed nor accepted for any damage
resulting from the use by the user of the final user-assembled product. By the
act of using the user-assembled product, the user accepts all resulting
If the buyers are not prepared to accept the liability associated with the use of
this product, they are advised to return this kit immediately in new and
unused condition to the place of purchase at the buyers’ expense.
Congratulations and thank you for purchasing the Radiowave 3.1m or 3.2m Extra kit.
Flying the Extra 300/330 is a very rewarding experience, as it should be for such an aerobatic
model. With the aircraft control surfaces set for precision aerobatics, the aircraft will perform
prescribed aerobatic patterns as used in IMAC (International Miniature Aerobatic Club) events
exceptionally well. With control surfaces set for freestyle flying, the aircraft will perform today’s
modern 3D aerobatic maneuvers to really showcase the aircraft’s aerobatic potential.
Please finish the Extra 300/330 according to the instruction provided in this manual. We do not
recommend altering the model in any way that could result in an unsafe model. To prevent any
possibility of flutter, please make sure that there is no slop or backlash on the control linkages.
Install gap seals, especially on the ailerons. Use only high quality, high-torque servos for all the
control surfaces.
Minimum Number of Servo’s per Panel
Minimum Torque Per Servo
300 in-oz
300 in-oz
300 in-oz
This manual provides very detailed assembly instructions for this model. Experienced modeler
may find these instructions much too detailed but we felt it is better to provide more detail than not
enough as to avoid mistakes that could be costly as well as time consuming.
The 3.1m & 3.2m Extra’s are designed for engines from 150cc to 200cc. Unlimited vertical
performance is achievable with these engines.
Please fly the Extra 300/330 safely and in a professional manner. Jtec Radiowave accepts no risk
or liabilities when customers use our products for any circumstance, occurrence, happenings,
bodily harm or death to yourself or anyone. Please follow the Academy of Model Aeronautics
(AMA) flight safety rules and regulations. Assume the use of our products at your own risk.
3.1m & 3.2m Extra 300/330 Kit Features
Constructed with laser cut lite-ply and birch-ply, and balsa parts
Interlocking Fuselage Design for self aligning & quick building
Foam core Wings, Horizontal Stab, Vertical Stab, & Rear Turtle Deck
Premium Fiberglass Cowl & Wheel Pants
Aluminum Wing Tube, Tail Tube, & Landing Gear
Designed For Canister Style or Tuned Pipe Exhaust Systems
Designed to Accommodate up to 3 Servos per Wing
Designed to Accommodate up to 2 Servos per Elevator Half
Built-in Rudder Tray for Pull-Pull Setup
Optional Bays for up to 4 Rudder Servos in the Tail
1. Required Accessories
There is no hardware provided with the kit since most modelers prefer to use their own brand of
hardware and accessories. Listed below is the hardware and accessories that you will need to
complete the model. In some cases, we have listed the brands that we have used and
recommend, although by no means are you required to use the brands mentioned.
Item Used:
Recommended Brand
8-32 Socket Head bolts
8-32 Lock Nuts
Landing Gear Axle
Wheel Collars
4 ½ or 5 Inch Wheels
6-32 x ¾” Socket
Head Bolts
¼ - 20 knobs
Du-Bro, Great Planes
Du-Bro, Great Planes
Du-Bro, Great Planes
Du-Bro, Great Planes
Sullivan, Du-Bro
Du-Bro, Great Planes
Landing Gear
Landing Gear
Landing Gear
Landing Gear
Landing Gear
Hatch Mounts, Cowl Mount
McMaster Carr
Tail Gear and Wheel
4-40 x 1 ½ ” Turnbuckles
Control Horns
4-40 Ball Links
4-40 x 2”
Titanium turnbuckles
Fuel Tank (50-60 oz)
5 inch Spinner
6-32 x 1” Socket Head
6-32 blind Nuts
Graph tech, J&J Tailwheels
Dubro, Robart
Dubro, Great Planes, Hanger 9
Rocket City, DuBro
Hangar 9
Wing Attachment to
Tail Gear
Elevator Control Rods
Air, Elev, Rudder
Air, Elev, Rudder
Air, Elev, Rudder
Ailerons Control Rods
Tru-Turn, Mejzlik
Du-Bro, Great Planes
Du-Bro, Great Planes
Fuel Tank
Horizontal Stab Attachment
to Fuselage
Hatch Mount, Horizontal
Stab Mount
Accessories that are required to mount the engine, radio, and servos are not included in the
list above.
The Push Rods can also be made from carbon fiber tube with threaded 4-40 rods at each
As we have made revisions some parts may no longer be required to build this kit
Fuselage Parts
Part ID.
1/8” lite ply
1/8” lite ply
1/8” lite ply
1/8” lite ply
¼” lite ply
1/8” lite ply
1/8” lite ply
1/8” lite ply
¼” lite ply
¼” lite ply
1/8” lite ply
1/8” lite ply
1/8” lite ply
1/8” lite ply
1/8” lite ply
1/8” lite ply
1/8” lite ply
1/8” lite ply
1/8” lite ply
1/8" lite ply
1.5” Phenolic Socket
7/8” Phenolic Socket
¼ “ Plywood Firewall
Fuselage side, front
Fuselage side, rear
Fuselage doubler
Tail wheel mounting plate
Motor Box Sides
Motor Box Top
Motor Box Bottom
Motor Box Bottom
Former, F1
Former, F2
Former, F3
Former, F4
Former, F5
Former, F6
Former, F7
Former, F8
Tank Floor
Fuselage Top, Front
Fuselage Top, Rear
Horizontal Stabilizer Doubler
Phenolic wing tube housing
Phenolic tail tube housing
3/8” x 3/8” Balsa
1/8” lite ply
1/8” lite ply
1/8” lite ply
1/8” lite ply
1/8” lite ply
Hatch longerons
Hatch mounting tabs
Hatch floor, front
Hatch former, front
Hatch former, mid
Hatch former, rear
Front turtledeck former
Rear turtledeck former
Rear Turtledeck:
1/8” lite ply
1/8” lite ply
1/8” lite ply
1/8” lite ply
1/4" lite ply
1.5”x 48” aluminum
1 ½ " x 48” Phenolic
Right wing panel
Left wing panel
Wing Root Rib
Wing False Rib / Wing Tube Support
Alignment donuts
Wing tube
Wing tube socket
Horizontal Stabilizer
7/8”x17.25 aluminum
1/8” lite ply
1/8” lite ply
Right Stabilizer
Left Stabilizer
Tail tube
Horizontal Stab Root Rib
Horizontal Stab False Rib / Tube Support
Vertical Stabilizer:
Vertical fin
Required Wood list:
3/8" x 3/8” Balsa
1/16” x 4” x 42”
1/16” x 36” x 4”
1/16” x 24” x 4”
3/32” x 4” x 36”
½” x 4” x 42”
½” x 4” x 36”
½” x 4” x 24”
¼” x ¼” x 48”
¼” x ¼” x 36”
½” Tri stock
¼” x ¼” x 48” Spruce
¼” x 12” x 12” Birch Ply
longerons (Fuselage)
Wing Sheeting
Fin, rudder, & Wing Sheeting
Stab Sheeting
Hatch & Turtle Deck Sheeting
Leading & Trailing Edge (Wing)
Leading & Trailing Edge (Wing)
Leading & Trailing Edge (stab & rudder)
Hatch Stringers (outer stringers)
Hatch Stringers
Firewall support
Fuselage Bottom Stringers
Wing Root attachment Doubler
Note: Before using any glue or cutting of wood, we suggest that you do some pre-assembly and
read all the steps to make sure that you understand the assembly procedure and how the parts fit.
We suggest you use 30 minute Epoxy or Aeropoxy on Motor box assembly and Carpenters glue
such as Titebond II for construction of the fuselage side. The benefit of carpenters glue during
assembly is it is easily cleaned and allows time for fitting parts together; also it will not become
brittle like CA does over time.
If you choose to run the DA-200 four cylinder engine you will notice the location for the firewall is
engraved into the motorbox sides. You will need to cut the motorbox sides to align with the
notches. (The pictures associated with this manual show the motorbox being cut for the DA-200)
Motor Box Assembly
Required parts:
Left Motor Box Side - MBSL
Right Motor Box Side - MBSR
F1 Former - F1
F2 Former - F2
F3 Former - F3
Motor Box Top - MBT
Motor Box Bottom - MBB1
Motor Box Bottom - MBB2
Fuel Tank Floor - TF1
1) Slide Former F1 into tabs on MBSL & MBSR. Do not Glue until next step.
2) Take Fuel Tank Floor, MBB1, and Firewall and slide into tabs on MBSL & MBSR. Using 30
minute epoxy glue TF1, MBB1, and Firewall into place on Motor Box sides.
3) Glue Former F2 and F3 into place using 30 minute epoxy.
4) Glue MBB2 between TF1 and MBB1 using epoxy or carpenters glue.
5) Clamp entire assembly and allow adequate time to dry before continuing to next steps.
Note: If you like you can Glue MBT into place at this time; however it may be easier to glue in
after assembly is complete and you have mounted your throttle servo, ignition and all engine
If you are building your airplane with the intention of using the DA-200 four cylinder engine you
will need to cut the motor box sides at the engraved line in the wood.
Fuselage Assembly - Fuselage Sides
Required parts:
Fuselage Side - FS1 (2 required)
Fuselage Side - FS2 (2 Required)
3/8" x 3/8" Balsa
Horizontal Stab Doubler - HSD1
Fuselage Doubler - FD1
Note: Remember you need to build a left and Right fuselage side so before gluing anything make
sure that you are building the correct side. We recommend building one side at a time so you do
not confuse yourself on which side you are building.
1) Lay a small piece of wax paper where the two fuselages sides that will be joined.
2) Glue FS1 and FS2 together.
3) Take horizontal stab doubler (HSD1), align with rear servo bays, tail tube hole and glue into
position with carpenters glue.
4) Take FD1 and match it to the tabs on the fuselage side making sure they align correctly before
gluing in place. It may be beneficial to Take Former F5 and test fit before gluing anything in
place. After checking alignment glue FD1 into place with carpenters glue.
5) Take 2 pieces of 3/8" x 3/8" balsa and splice pieces together with at least a 45 degree splice to
form a strong joint. Repeat this step three more times to create all the longerons you will need
to complete the fuselage sides.
6) Take longerons and run a bead of glue down one side and attach to bottom edge of fuselage
sides. Longerons will stop at front edge of horizontal stab doubler. Repeat step for top edge
of fuselage side but make sure not to cover any of the tabbed portion in which the fuselage top
7) Repeat Steps 4-6 for other fuselage side. Again make sure that you build the opposite side of
the first one you did.
8) Rest fuselage side on flat surface and weights to FD1 and longerons to help make sure pieces
are set in place correctly. Allow time to dry before continuing to the next steps.
Fuselage Assembly
1) Lay the fuselage top pieces (FTF1 & FTF2) on your building table and glue the two pieces
together using carpenters glue.
2) Lay the motor box assembly on the fuselage top, matching up the tabs on the motor box
assembly with the slots on the fuselage top and test fit motor box to fuselage top. Repeat this
step for every fuselage former.
3) Glue the motor box assembly to the fuselage top using at least 30 minute epoxy.
4) Now, take Formers F4 - F7 and after test fitting them glue them into position on the fuselage
top using carpenters glue and a square to help you align them for the best fitment. To help
you keep the formers in place you can also use a drop of CA to tack the formers into place.
Note: You will glue Former F8 into place in a few steps from now.
5) Allow formers to dry for a few minutes before attempting to attach the fuselage sides.
6) Take a fuselage side and test fit against formers to make sure all tabs are correctly in place. If
needed sand former tabs or longerons to help achieve the best fit. You are looking for no gaps
in any of the joints.
7) After test fitting both fuselage sides, use carpenters glue to glue fuselage sides into place
making sure to get an adequate amount of glue on the all formers and fuselage top. Use a
square to help make sure that everything is aligned properly.
8) Take Former F8 and glue into position, butting former up against the horizontal stabilizer
9) Take long clamps and clamp fuselage sides into place on formers. While the fuselage is self
aligning you do want to make sure that all your tabs are correctly seated and glued into
position and nothing appears to be twisting because it is too tight.
10) Place the tail wheel plate TWB1 at the aft end of the fuselage sides. Check the alignment of
the fuselage then glue in TWB1.
11) After the fuselage sides are glue in place and cured you need to make the bottom stringers for
the fuselage. Take (6) ¼” x ¼” x 48” spruce pieces and splice them so you end up with (3)
92”+ pieces.
12) Starting at the tail wheel plate and working your way forward; glue the spruce pieces into place
using titebond. The three long pieces are for the three center slots on the bottom of the fuse.
13) Cut the ¼” x ¼” spruce pieces flush with the front of the F1 former.
14) Use the excess spruce pieces to do the outer most bottom stringers. It may require you to
splice the spruce pieces again to get the correct length you need.
15) After you have finished the stringers you need to sheet the bottom of the fuselage between
formers F1 and F3. Starting at the bottom of the fuselage side take some 3/32” x 4” x36” balsa
and sheet the bottom of the fuse, it may be easier to use come medium CA to glue the
sheeting in place. Depending on the hardness of your balsa sheeting you may want to use
some ammonia to get the balsa to follow the former shape.
NOTE: Before sheeting the bottom of the fuselage you may want to jump ahead to the landing
gear mounting section so it is easier for you to mount the angle aluminum that goes inside the
16) After you sheet the bottom of the fuselage between formers F1 and F3 you will need to go
back and cut out the landing gear area. You will see that it is the notched section on the
bottom of the fuselage.
17) Insert the phenolic tubes for the wing and tail along with the aluminum wing and tail tubes.
With the fuselage still upside down on the workbench, from the rear of the fuselage, sight the
wing and tail tubes to check if they are parallel to each other. You can also measure the
vertical distance of the wing tube socket ends to see if both ends are equal. If the wing tube
vertical distance from the workbench is not equal, prop up one side so that the wing tube
distances are the same.
18) Now, check the vertical distance of the tail tube from the workbench to see if both ends have
the same distance. If the tubes are not parallel to each other, prop up one fuselage side with
shims at the tail tube end so that the distances are the same, and place weights on the
fuselage so the fuselage will twist with the shims on the fuselage side. Sight again to see if
both wing and tail tubes are parallel. The other option is to slightly file the holes for the tube
sockets so that the phenolic pieces are parallel.
Removable Hatch Assembly
Required Parts:
Hatch Floor - H1
Front Hatch Former - H2
Middle Hatch Former - H3
Rear Hatch Former - H4
3/8" x 3/8" balsa stringers
1/4" x 1/4" balsa stringer
Hatch Mounting Tabs
The first thing you want to do when constructing the hatch is to make the tabs for mounting the
hatch to the fuselage. This will make it much easier to find the position of the mounting screws for
the hatch.
1) Find the (6) ¼” Hatch mounting tabs labeled HMT. Get some 3/8” ply and cut (6) 1” x 1”
pieces. Mark the center of the 1” sq ply and drill out for 8-32 blind nuts. Glue the blind nut to
the 1” sq ply. Next, align with the mounting hole on the HMT and glue blind nut and ply piece
to the HMT.
2) Take (2) 3/8” x 3/8” x 48” balsa stringers and align them with the top of the fuselage where the
hatch is to be mounted, sitting them on top of the 3/8” balsa fuselage stringer.
3) Next, take (3) of the Hatch Mounting Tabs and space them evenly on the 3/8” sq stringer,
mount the tab so it is flush with the top of the stringer. The mounting tab will overhang the
stringer and drop down to the fuselage.
4) Use wood glue or epoxy to attach the hatch mounting tabs to the stringers. Repeat this step
for the other side of the fuselage and make sure to place the mounting tabs in the exact same
position because you will use them as a reference for the mounting holes in the fuselage.
5) After you have completed mounting the tabs on the stringer you will want to mark the mounting
tab hole location on the fuselage. For this you will want to use the left hatch stringer on the
right side of the fuselage and then the right hatch stringer on the left fuselage side. Again it is
key that you have the stringers spaced identically so your hole locations will line up properly
when you complete the hatch.
6) Next, you will need some 3/8” lite ply or birch ply and cut it into (6) 1 ½” squares to create a
doubler for the inside of the fuselage.
7) Glue the 1 ½” doublers you created to the inside of the fuselage, making sure they line up
properly with your mounting tabs.
8) Drill your hatch mounting holes in the fuselage, using (6) 8-32 screws to mount the hatch.
Hatch Framework
1) Find the H2 former, H3 former and H4 former and while using a square glue them into position
on the Hatch floor (H1). We suggest only tack gluing the H4 former because you will need to
set the angle on it after the rear turtledeck is completed, if you wish to permanently glue H4 in
place you will want to set it to a 25 degree rearward angle to match the angle that is on the
rear turtledeck.
2) Now take the (2) 3/8" x 3/8" x 48” balsa stringers that you created and glue to the left and right
edge of the hatch floor (H1). The 3/8” stringer should overhang H1 just slightly.
3) Moving on to the ¼” x ¼” balsa stringer, take two stringers and splice them together (this will
depend on the length of your balsa stringer). After splicing the two stringers, glue into position
on formers H2 and H3. They will be the outermost stringers which go the full length of the
hatch. Again, you may want to wait until you have set the angle on H4 before you glue the ¼”
stringers to it.
4) Next, take the rest of your ¼” x ¼” balsa stringers and glue them into position on formers H2
and H3 aligning them so they are flush with the front of former H2.
5) Install a 1/4" x 1/4" balsa stringer on the outer edge of the top of the hatch floor, right behind
H3 and extending all the way to H4. Repeat for the other side.
6) With the hatch mounted to the fuselage the hatch should be roughly 3/32” shorter on both
sides of the fuselage.
Hatch Sheeting
Note: Before sheeting the hatch portion we recommend completing the rear turtledeck portion of
the fuselage. This is because the angle on the H4 former needs to match the angle that is built
into the rear turtledeck. So if you have not completed the rear turtledeck jump ahead to that
section now.
1) After completing the rear turtledeck, you are now ready to complete the work on the hatch
portion of the fuselage.
Note: When you sheet that hatch make sure that you have the hatch permanently mounted to the
fuselage, if you do not the hatch may want to warp while building. We have found it to be easier
to lay the sheeting down in individual pieces instead of one big sheet.
2) To sheet the fuselage, first take (2) sheets of 3/32” x 4” x 48” sheeting and cut them to the
complete length of the hatch, making sure you leave enough sheeting on the rear of the hatch
to match the angle that you set on H4.
3) Taking one of the sheets you just cut; align the sheeting with the hatch and fuselage so the
sheeting buts up to the fuse. We have found that it may be easier to glue the sheeting in place
if you lay the fuselage on its side so the glue does not want to run. Using CA, run a bead of
glue down the 3/8” stringer to glue the edge of the sheeting in place. Lay some wax paper
down on the fuselage to make sure you do not glue the hatch to the fuselage while doing this.
4) Next, take your CA and run a bead down the next ¼” stringer and lay the sheeting in place.
Depending on the hardness of your wood it may require some ammonia to help shape the
wood. Repeat this step for the next stringer or until that first sheet is layed down completely.
5) Repeat step 3 and 4 for the other side of the hatch.
6) After gluing the outer most sheeting into place we are going to start moving inward with the
7) Take (1) sheet of 3/32” x 4” x 36” and edge glue it to the sheeting already layed down. As like
before run a bead of glue down the nearest stringer and lay the sheeting into place. Continue
doing this until the sheeting is completely layed down.
8) As you come towards the center of the hatch you will be left with a triangle shaped section. If
you have any sheeting left over from sheeting the rear turtledeck you may want to use it to
create the shape of the triangular sheeting you need. If you do not, then you will need to take
another piece of the 3/32” x 4” x 36” sheeting and cut it to the shape you need.
9) As like the other pieces of sheeting, edge glue the triangular piece into place and glue it to the
¼” stringers.
10) Before you cut your sheeting shorter we recommend mocking up your canopy and positioning
at the length that you would like. If you want the plane to look like an Extra 300, you will want
to leave the canopy long since it is a two place aircraft. For something like an Extra 330SC
you will want to have the canopy short since it is a single place aircraft.
11) Once you decide on the length of the canopy you want use it as a template and mark the
sheeting with a pencil where the canopy will sit.
12) We recommend measuring in about 2” from the canopy line you created and making your cut
line for the sheeting at this point.
13) To complete the hatch section, fill in any low spots on the sheeting with some light weight
spackle and sand the turtledeck to shape.
Required Parts:
Foam Turtledeck
Balsa Sheeting
Turtledeck former - TD1
Turtledeck former - TD2
Sheeting Turtledeck
1) Take four to five pieces of pliable balsa sheeting and edge glue them together along their long
2) On one side of balsa sheet apply an extremely thin coat of 2 hour epoxy or gorilla glue (if using
gorilla glue, remember gorilla glue expands a lot when drying so be very careful of how much
you use).
3) Remove Turtledeck and inner foam piece from foam block. Lay balsa sheeting (glue side up
into block following the curve of the block. To help soften and shape the balsa you may want
to dampen the balsa on the unglued side with some ammonia or water.
4) Lay Foam turtledeck and inner foam piece back into foam block so that the balsa take the
shape of the turtledeck. At this point you can trim up excess balsa sticking out of the foam
block. Apply a lot of weight to inner foam piece to help make sure balsa sheeting bonds to
turtledeck properly.
NOTE: At this point you do not want to glue the turtledeck onto the fuselage until the front hatch
has been completed. After the hatch has been completed you can get the correct angle for the
rear hatch former (H4) and front turtledeck former
NOTE: Capping the front and rear of the turtledeck should be done after the turtledeck is glued to
the fuselage. If the turtledeck width does not match up with the fuselage width, it will be difficult to
force the turtledeck width to match the fuselage width front and rear already capped.
Installing the turtledeck Assembly
This step is to be completed before the front hatch is sheeted.
1) Using the hatch to set the correct space for the turtledeck mark the location of the turtledeck
on the fuselage.
2) Tack glue small pieces of scrap 3/16 by ½ x 3 balsa on the fuselage sides where the turtledeck
is to be glued. This will help line up the turtledeck with the fuselage sides while it is being glued
to the fuselage.
3) Glue the turtledeck to the fuselage with either epoxy or Gorilla glue and hold it down with
several pieces of masking tape to the fuselage side. The nice thing about the Gorilla Glue is it
sandable if you use too much glue.
4) Check the alignment of the turtledeck with the fuselage. If some part of the turtledeck is inside
the fuselage line, place a balsa spreader bar at the inside of the turtledeck to force the
turtledeck to match up with the fuselage side.
5) When dry, remove the temporary pieces of 3/16 x ½ x 3 pieces from the fuselage side. Take
TD1 and TD2 formers and glue them into position on front and rear turtledeck portion. Former
TD1 should match the angle that hatch former H4 is set to. Former TD2 should be square to
the fuselage.
6) Sand the turtledeck flush with the fuselage sides and fill any low spots with light weight spackle
as needed.
Wing Construction
Required Parts:
Foam Wing (2)
1/8” Plywood Root Rib (2)
1/8” Plywood False Rib (2)
1/16” Balsa Sheeting (36” & 42”)
½” Leading & Trailing Edge Balsa Stock
¼” Birch Ply
(4) ¼”-20 Blind Nuts
1 ½” phenolic Tube
¾ oz. Fiberglass
To construct the wings the first thing we need to do is prepare the wings and make your sheeting.
NOTE: When building the wing if you would like to add a full length spar to the wing please feel
free to do so. Many of the competition airplanes on the market today do not use any type of spar
but if you feel that with your flying style it is a good idea then please do so. Since the wing is built
by the consumer, JTEC Radiowave accepts no liability if you have any type of wing failure no
mater if you build the wing with or without a spar.
If you choose to add a spar to your wings we suggest either a ¼” x ¼” hardwood spar or even a
flat carbon fiber piece shaft (available from CST or Aerospace Composites). Route out the wing
based on the size of the spar you chose, running the spar right down the wing tube the full length
of the wing making sure to notch your root rib for the spar to help lock it into the wing.
1) The first step in building the wings is making your sheeting. To do so you will need to take (16)
sheets of 1/16” x 4” x 42” and (12) sheets of 1/16” x 4” x 36” balsa and make (16) sheets that
are approximately 58 ½” long.
2) Using your wing as a reference for your sheeting, you will want to start your first sheet running
parallel to the trailing edge of the wing. When laying out the sheeting, reverse the sheets for
the opposite side of the wing so no two joints are in the same location for both the top and
bottom. We are not gluing at this time, we are just using the wing to help visualize the layout
of the sheeting.
3) Continue to stager the sheets as you work your way up to the leading edge of the wing. When
laying out the sheets we suggest taping the sheets together and using titebond to edge glue
the sheets together.
4) When you have your sheeting all laid out and edge glued, sand the sheeting smooth on a flat
NOTE: If you do not start your sheeting at the trailing edge and work forward you probably will not
have enough sheeting to complete the wings.
5) Moving on to the phenolic tube, take one of the 1 ½” x 18” pieces of phenolic tube that you
have left over from the fuselage and seal one end of it with scrap balsa and sand smooth. A
piece of thicker balsa is recommended for this.
NOTE: The phenolic tube should be approximately 18” if you are slightly less don’t, worry about it
because you will be cutting the root angle.
6) Next lightly sand entire phenolic tube so when you are gluing it into place it bonds better.
Trial fit phenolic & wing tube support. Sand wing tube support flush with the foam core on both
7) Before sheeting you need to trial fit the wing to the fuselage to set the correct angle for the root
rib and mark the location for the wing attachment points.
8) To set he angle of the root rib you will want measure out 1 ¾” from the front of the wing and
then take a long straight edge and draw a line from that point to the very edge of the trailing
NOTE: You are not looking to take any material off the trailing edge.
9) After you have marked your angle, cut the wing to set your root angle. You may need to sand
the root of the foam to get a perfect fit.
10) Next, find and trim the 1/8” lite ply root, sand flush with the foam wing.
11) Cut yourself out (4) 1 ½” x 1 ½” birch ply pieces and drill them out for a ¼-20 blind nut. Glue
the blind nut in place and then glue to the plywood root.
NOTE: Another option for your wing attachments would be to use something like the anti rotation
pins that Desert Aircraft sells. These will leave a threaded stub out the root of the wing.
12) Next, square up the plywood root to the foam wing and glue in place with a minimum of 2hr
epoxy. You will sheet over the plywood root so there will be no joint showing on the top or
13) Glue in phenolic & false rib wing tube support using polyurethane glue or epoxy. When gluing
in your phenolic tube make sure to leave an overhang on the false rib and also make sure the
phenolic is glued to the root rib.
NOTE: If using polyurethane glue like Gorilla glue, make sure to leave your wing tube inside the
phenolic tube. If you do not your wing tube may become really tight when the Gorilla glue
14) After your phenolic and false rib are glued into place take some ¾ oz. x 12” x 24” fiberglass or
carbon fiber cloth and glass over the phenolic and past the area around the phenolic tube,
make sure to do this to both sides of the wing.
15) Once you have glassed the phenolic section you are ready to sheet the wings. When sheeting
the wings we recommend using Gorilla glue because it will bond extremely well with the foam
and balsa and it is also very easy to sand if you have excess.
16) To sheet the wings we suggest pouring some Gorilla glue on the balsa sheeting and spreading
an extremely thin coat of it evenly on the balsa.
17) Next, take a spray bottle and give the foam wing a very light mist of water to help activate the
Gorilla glue. Square up the sheeting on the wing and place in the foam shuck.
18) After both sides are complete tape the shuck to keep the wing in place and then weigh down
the entire wing. You will want to use around 300 pounds of weight when sheeting a wing and
make sure you do everything on an extremely flat surface.
19) When the wing sheeting is completely cured, trim and sand sheeting flush with foam core and
plywood root.
20) Next, cap the leading edge of the wing with 1/2" balsa and the trailing edge with1/8" balsa;
sand flush with the wing sheeting.
NOTE: To give a superior snap when flying we suggest a sharper leading edge.
21) To cut out the ailerons, refer to the wing reference for the aileron dimensions. Use ½” balsa for
the wing trailing edge and the aileron leading edge, making sure to double bevel when sanding
to maximize the amount of throw you can achieve.
22) As with the ailerons, refer to the wing reference sheet for the aileron placement.
23) Before gluing in the servo boxes use a long piece of copper tube to make your servo lead hole.
You should be able to get a long piece of copper from your local hardware store. Heat one
end with a torch. The wing root has a location for the servo wire hole already so you can use
that as a guide for making your hole. Keep track of the tube as you go from servo box to servo
24) Your wings are now complete; you can now cut the slots for your hinges and make sure
everything is beveled like you want it.
Horizontal Stab Construction
Required Parts:
Foam stabilizer (2)
1/8” Plywood Root Rib
1/8” Plywood False Rib
1/16” Balsa Sheeting
½” Leading & Trailing Edge Balsa Stock
7/8” phenolic Tube
The horizontal stab construction is virtually the same as the wing construction; it is just on a
smaller scale.
1) Just like you did on the wing the first step is to prepare stab sheeting using 1/16” x 24” balsa.
2) Take the 7/8” phenolic tube and cut two phenolic pieces for the horizontal stab. Seal one end
using a thick piece of scrap balsa.
3) As you did on the wing you will need to cut the root angle for the stab. Measure approximately
¾” in from the leading edge of the foam stab and make your mark to cut the angle.
4) Cut your angle into the stab, trial fit, and sand both root rib and phenolic just like you did on the
5) Glue the root rib into place and then glue in phenolic and false rib with epoxy or Gorilla glue;
again leaving a little overhang on the false rib side and making sure the phenolic is locked into
the root rib
6) Sheet the stabs, place in the shuck and weigh down.
7) Once the glue is cured, sand sheeting flush with foam and the root rib.
8) Glue on the ½” balsa leading and 1/8” balsa trailing edges and sand to shape.
9) Before cutting the elevators we suggest waiting until you set your stab incidence.
NOTE: We have found it to be easier to set the incidence on the stabs before you cut the
elevators out.
10) After you have set the stab incidence you can cut the elevators out using the elevator
reference sheet for your dimensions. If you are building a Extra 330 and want the scale look
then you will want to add the counter balance on the stab. If you are doing the Extra 300 then
you will have no counter balance.
11) Again, just like the wing add your ½” trailing edge to the horizontal stab and your ½” leading
edge to the elevator.
12) Sand and double bevel the elevator to achieve max throws.
13) Finally, cut the slots into the elevators for your hinges.
Rudder Construction
Required Parts:
Foam Vertical Stab
1/16” Balsa Sheeting (36”)
½” Leading & Trailing Edge Balsa Stock
1/8” Balsa Strip
The rudder construction is very similar to the wing and horizontal stab construction; you just get to
skip a couple of steps since you do not have to deal with wing tube and root rib.
1) As you did with both the wing and horizontal stab the first step is to lay out your sheeting and
edge glue it together. To sheet the tail you will use the 1/16” x 36” balsa.
2) Just like you did on the wing lay your sheeting out from the trailing edge of the rudder and work
your way forward.
3) Edge glue or tape your pieces together. With the rudder sheeting you will have some excess
sheeting so instead of wasting another piece use as much of the excess pieces you have as
your next piece.
4) Glue the sheeting onto the foam using the same technique to apply the Gorilla glue as you did
on the wing and horizontal stab.
5) Place the rudder into the shuck and weigh down with a large amount of weight.
6) After the glue is dry, trim up any excess wood.
7) Add your ½” leading edge and 1/8” trailing edge to the rudder.
8) Cap the top of the rudder using your choice of balsa. We suggest anything from 1/8” balsa to
1” to achieve the look that you want.
9) Follow the Rudder reference sheet to cut the rudder and vertical stab to the appropriate size.
NOTE: If you would like to change the size of the counterbalance you are more then welcome to
do so.
10) After you have cut your rudder, add your ½” trailing edge to the vertical stab and your ½”
leading edge to the rudder. Double bevel the rudder to achieve the maximum throw. Make
sure to leave 8” or so on your trailing edge of the vertical fin because you will need to glue it to
the rear of the fuselage.
11) Cap the bottom of the vertical fin with 1/8” x 4” sheeting and shape to the sheeting to match
the taper on the fuselage.
12) When building your rudder you can so make the appear more scale by tapering the bottom of
your rudder and rounding the bottom rear portion of the rudder and the rudder reference sheet
13) Now you are ready to glue the rudder to the fuselage. Using epoxy glue the vertical fin the
rear of the fuselage. Make sure to square up the rudder to the fuselage before gluing it into
place. You will want to make sure the fin is squared to the fuselage vertically.
14) Use masking tape to secure the vertical fin to the fuselage while the glue is drying.
15) To make a smooth transition from the rear turtledeck to the vertical fin you will need to make a
fairing that tapers to the rear of the fuselage.
16) After the rudder is mounted take some 1/16” balsa and edge glue it to the rear of the turtledeck
following the curve of the turtledeck. At the rear of the fuselage your fairing should be tapered
down to about 1” tall or so (use the sweep of the turtledeck to find the correct angle).
Setting Wing Incidence
1) To help level the airplane the fist step we suggest when setting the incidence is installing
landing gear to fuselage. The (4) landing gear bolts should pass through the aluminum angle.
2) Without the hatch on the fuselage, bring the tail of the airplane up until the front top plate is
3) Install one wing panel and use an incidence meter to set the wing incidence at 0 degrees. To
set the incidence on the wing it may require you to slightly open up the wing bolt holes in the
4) Once the wing is set to 0 degrees glue in the round anti-rotation donuts with epoxy or titebond.
5) Before moving on to the other wing, go back and double check that the wing is set to 0
6) Repeat steps 2-5 for the other wing.
Setting Stab Incidence
Setting the stab incidence will be very similar to setting the wing incidence.
1) Install one stab to the fuse. Trial fit the stab to the fuselage and sand if needed so there are no
gaps between fuse and stab.
2) Use your incidence meter to set the stab incidence to 0 degrees.
3) You will see that the root has (2) hole locations for the stab bolts. Take a pencil and mark the
center of those hole locations while the stab is still set to 0 degrees.
4) Remove the stab and drill the fuselage to accept the 8-32 bolt that will hold the stab on.
5) Install the stab again and double check your incidence to make sure it is still at 0 degrees. If
needed open your hole in the fuselage to get the stab to 0 degrees.
NOTE: When setting the stab incidence, do not remove any material from the root rib on the stab
if you need to adjust, remove from fuselage only.
6) Now insert 8-32 blind nuts into the fuselage and glue them into place. Depending on the
length of your blind nut it may be necessary to glue the blind nut into a plywood block.
7) Before glue has set, check your incidence one more time to make sure it is still correct.
8) Repeat steps 1-7 on the other horizontal stab.
Installing Hard Points
Installing the hard points for the ailerons, elevator and rudder are the same so repeat these simple
instructions to do so for every surface. As you will see in the instructions we like to use a plywood
plate on both sides of the surface to create the hard point. We do this to spread the load of the
hard point. If you prefer to use a hardwood dowel as your hard point, please feel free to do so just
install your servos first to make sure the hard point is in the location you want.
1) Get yourself a sheet 1/8” plywood (preferably birch or aircraft ply) and cut it into 1 ½” x 3”
pieces for the ailerons and elevators. Depending on the number of servos you are using, you
will want anywhere from (6-8) pieces this size. For the Rudder cut yourself (2) 3” x 3” pieces.
NOTE: The larger the piece you cut for the hard point, the more it will spread the load. So, feel
free to make the hard points slightly larger.
2) Find the location on the aileron, elevator and rudder that you want the hard point to be.
3) Remove the balsa sheeting and foam if needed from this location to get a nice flush fit of the
hard point.
4) Glue the hard point into place with 30 minute epoxy. Do this for both sides of the surface,
making sure you line up your hard point locations exactly.
5) Sand surface to make sure hard point fit perfectly.
Servo Boxes
Included with the kit you should find some lite ply pieces to make the servo boxes for the wings
and stabs. You should have enough parts to make (10) servo boxes, so depending on how many
servos you are using you should be set.
1) The servo boxes should assemble just like a little jig saw puzzle, when putting them together
you can use CA glue them.
2) Use the wing and horizontal stab reference sheets to find the approximate placement of the
NOTE: For placement of the wing servo boxes we suggest squaring the servo box to the aileron
and not to the wing tube. When you look at the wing reference sheet you will see that the servos
appear to be at a slight angle. This will line your servos better and give you a more linear throw
and better resolution on your servos.
3) Using a Dremel with a Rotozip bit remove the foam from the area you marked for the servo
boxes. Be sure that the bit does not cut into the surrounding top sheeting. To do so set the
Dremel on a slow speed or the foam will melt. Remove the foam all the way up to the top
sheeting but make sure you do not go all the way through.
4) Glue the servo boxes in using epoxy or Gorilla glue. If using Gorilla glue, be careful of how
much the glue expands.
5) Repeat steps 1-4 for all the remaining aileron and elevator servo boxes.
Mounting the Cowling
Mounting the cowl should be a fairly simple process because the F1 former and cowl ring already
have the mounting holes. You may want to temporarily mount your engine before you do the cowl
ring to make sure you get the correct cowl spacing.
1) Take some ¼” or 3/8” birch ply and cut it into (6) 1” x 1” blocks.
2) Drill the block to accept an 8-32 blind nut and glue the blind nut in place.
3) Next, take the cowl ring and mount the ring to the fuselage using (6) 8-32 x 1” bolts and large
flat washers. The upper and middle bolts will mount from the fuselage side while the bottom
two bolts will mount from the cowling side.
4) Take some titebond and spread it on the inside of your wood blocks that you created and then
thread them on to each 8-32 bolt. Tighten the bolts so the wood blocks seat on the fuse and
cowl ring and allow enough time for them to dry.
5) After the blocks cured, remove the cowl ring and slide it into position on the cowl. The cowl
ring should but up to the back of the cowling (this may depend on what engine you are
6) Using 2hr epoxy, glue the cowl ring into place.
Mounting the Landing Gear
Before sheeting the bottom of the fuselage it is recommended that you get the gear mounted.
1) To mount the gear to the fuselage you will need (2) pieces of angle aluminum that are 1/16” x
1” x 8”.
2) Take one of your aluminum angle pieces and drill three holes on one the faces of the angle,
make sure to space the holes evenly apart. We recommend drilling the angle to accept 8-32
screws; you may also want to offset the bolt holes towards the outer edge of the angle
aluminum. Repeat this for the other piece of aluminum angle.
3) Take your aluminum angle and align it so one side of the angle (un-drilled side) is flush with
the notched section on the bottom of the fuselage; you will notice that the F2 former is also
notched to accept the angle aluminum.
4) Use your aluminum angle as a template to mark the center of the bolt hole locations on the
motorbox sides of the fuselage with a pencil.
5) Drill the bolt hole locations of the motorbox side so a 8-32 blind nut will fit properly.
6) Using 8-32 x 1” bolts and large flat washers run the bolt through the aluminum angle and
motorbox side and tighten down using the 8-32 blind nuts. (The head of the bolt should be on
the angle aluminum side).
7) After the blind nuts are set into place, glue them to make sure they do not ever back out.
8) Re-insert your 8-32 bolts this time using blue or red locktite. This is a permanent piece so it is
ok to use red locktite if you prefer.
9) Repeat steps 3-8 for the other side.
10) Now, take your landing gear and center it on the fuselage and aluminum angle. Find the
center on the aluminum angle and then mark the gear for (4) 8-32 bolts.
11) Use a drill press to drill out the landing gear for the 8-32 bolts.
12) Mock up the landing gear on the fuselage again and drill the aluminum angle for the (4) landing
gear bolts.
After a final sand of everything you should now be ready to cover your airplane.
Remember sanding is one of the most critical parts of building an airplane, if you do a
good job of final sanding your results will show when your extra is completely covered.
Prepare Cockpit Area and Install Canopy
1) Paint the cockpit area with a color of your choice, and install front and rear instrument panels,
and a pilot.
2) Trim the canopy slightly larger than the trim line marked on the canopy and check the fit to the
front hatch, and re-trim, if required.
NOTE: When looking at the canopy and airplane from the side of the airplane, the canopy should
follow the rear turtledeck line. This may require you to cut a fair amount of material off of the front
of the canopy. Take the time to get the canopy trimmed up properly because it will really improve
the overall profile of the airplane.
3) When satisfied with the fit, glue the canopy to the removable front hatch. Do this with the
hatch bolted to the fuselage.
4) After the glue has dried, add some vinyl trim (¾ inch wide) around the canopy/hatch glue line
for improved looks. Vinyl trim is available in any sign shop in your area.
Install Fuel and Smoke System
1) Install the fuel tank on top of the fuel tank plate located in the front of the fuselage.
2) We like spot gluing in a piece of foam for the tank to rest on, and cutting slots on the fuel tank
plate so pieces of Velcro or can be used to secure the fuel tank.
NOTE: If using the 4titude fuel tanks, JTEC offers a tank mount designed to work with the tank
(tank mount sold separately form kit).
3) You also may want to make preparations for a smoke tank now, should you decide to install a
smoke system later.
4) When mounting the fuel tank we recommend mounting it as close to the wing tube as possible,
this way as fuel burns off while flying the CG is not effected.
Radio Installation
1) Install the servos for the ailerons and elevators in the locations that you selected. The servo
boxes may need some sanding to achieve a proper fit for your particular brand of servo. Once
the servos are installed, fabricate the push rods to connect the servos to the control horns.
The elevator push rods can simply be made of 4-40 all thread since the push rod length is so
2) We recommend that the rudder servos be installed in the rear of the fuselage with a direct
linkage to the rudder. If you prefer you can mount the rudder servos in the provided rudder
tray and run a pull-pull setup on rudder. You may want to see how your airplane is balancing
to determine the location to mount the rudder servos
3) Make appropriate mounts for installing you receiver, batteries, switches, and antenna routing
tubes. Remember to keep the receivers at least 12” from the ignition module and separate the
antennas from the servo leads as much as possible. Spending a little extra time here to do
this may save time at the flying field trouble shooting radio issues if any. Additionally, we try to
keep the batteries positioned so that they can be mounted securely, but also easily moveable
for quick CG changes if needed during initial set-up.
Servo Recommendations
9157 x 6
9157 x 2
9157 x 2
S-9650 Mini
BLS 157 x 4
BLS 157 x 2
BLS 157 x 2
S-8711 x 6
5955 x 6
S-8711 x 2
5955 x 2
S-8711 x 3
5735 x 2
S-8101 or any coreless
Engine Installation
As you should have noticed while building the airplane, the firewall is installed with 3 degrees of
right thrust built in it and the mounting locations for the Desert Aircraft DA-150/170/200 are
already cut out.
1) Prior to mounting the engine we strongly suggest using a lightweight fiberglass or carbon fiber
cloth with resin to provide extra strength to the firewall mounting. This can be done easily by
laying the cloth across the firewall and down the sides of the engine box about 4 inches.
2) Using (4)1/4-20 bolts, (8) large fender washers, and (4) lock nuts; mount the engine to the
firewall using blue locktite and the large flat washer on both sides of the firewall to help spread
the load of the bolt.
NOTE: We recommend 1 degree up thrust on engine (equal to about 1 fender washer); this will
give you improved flight tracking on upright and inverted 45 maneuvers.
3) Cuts holes as required for fuel tubing, and connect the tubing to the engine and route the vent
line as necessary. You will see the motorbox bottom plate there is a place to mount your
throttle servo. If you choose not to use the space provided for the throttle servo or your engine
requires the throttle to be mounted somewhere else; determine your servo location and cut
holes as necessary for the throttle push rod, and install your throttle servo.
4) Cut holes in the cowling for muffler exhaust pipes and install cowl. The two bottom bolts of the
cowl ring are bolted from the front of the cowl ring; reach in from the exhaust hole at the
bottom of the cowl to secure the bottom cowl bolts.
NOTE: For canister exhaust or tuned pipes use a 90mm drop stainless steel flex header and we
recommend either MTW 110 canisters, MTW RE3 tuned pipes, KS 95 canisters, or KS 1090 tuned
Setting Your Center of Gravity
Now, with everything on the airplane such that it is practically ready to fly except for the wing
panels and wing tube, check the initial CG using the method described below. Note that this
method does not actually determine the actual CG, but a balance point, which, when the wing
panels are installed will place the CG at a good position for initial flights.
1) With the wing panels and wing tube off, lift the aircraft with your fingertips at the wing tube
socket on both sides of the fuselage. The aircraft should balance level, or with the nose just
slightly low.
Control Throws
1. When setting your throws we recommend using CRC or similar throw meters. On all
surfaces we use 1 ½” metal servo arms, except for throttle which we use a ¾” metal servo
arm on.
NOTE: Your transmitter percentages will be different then the measurements below, especially if
you need to add differential for the ailerons.
Low Rate - 25 degrees up & down
Middle Rate - 35 degrees up & down
High Rate - 40 degrees up & down
Expo - 25%
Expo - 45%
Expo - 65%
NOTE: You may find the airplane rolls more axial with up to 5 degrees more up then down when
setting up your Ailerons (especially on the Extra 330 due to the wing position). Again, this is a
physical measurement with throw Meters, if you choose to do this through the differential settings
in your transmitter the percentages will most likely be higher.
Low Rate – 12 degrees up & down
Middle Rate – 25 degrees up & down
High Rate – 35 degrees up & down
Expo - 25%
Expo - 45%
Expo - 65%
Low Rate – 30% available throw
Middle Rate – 65% available throw
High Rate – Full throw
Expo – 50%
Expo – 65%
Expo – 85%
Initial Radio Mixes:
2 - 6 % up elevator with either left or right rudder
2 - 4 % right aileron with left rudder
2 - 4 % left aileron with right rudder
NOTE: Due to the wing position on the Extra 330 you initial Radio Mixes may be slightly higher
then what is listed above. The mixes in your airplane will also be dependent on things like your
balance, control horn placement, and control throws. Every pilot has there own preference on
how an airplane should feel, the above settings are what we have found to work very well and give
you an extremely competitive flying airplane no matter your skill level. We strongly suggest not
put any of your mixes on a switch because there may be that time that you forget to activate your
switch and end up getting yourself in trouble. We have the philosophy that not matter what
attitude your airplane is in it should still need the same amount of mix.
Flying your Extra
Initial Flight – We suggest before your initial flight you go through the entire airplane and make
sure all your nuts and bolts are tight and loctite everything. Make sure to seal all your flying
surfaces to help reduce the risk of flutter. Have another pilot check over everything for you
including the direction of all surfaces. Make sure that you have all your fail safes set like you want
and that you can cut your engine through the radio if needed.
For the first few flights we suggest flying your new airplane with a little extra altitude until you are
completely comfortable with it. During the first flight, check the glide and stall characteristics so
when you come in for landing there are no surprises. If setup properly your extra should stall
straight and not look to drop a wing. Please land and check control surfaces, hardware and
engine for tightness. Remember, to setup your airplane properly you first need to get the balance
of the airplane how you like it and then you can work on your mixes.
If you plan on using your aircraft for precision aerobatics please take the time to trim your aircraft
properly. If your CG is set up for precision aerobatics and you want to fly 3D/freestyle aerobatics,
you may want to experiment with moving the CG aft by adding a small amount of weight in the aft
end of the fuselage to see you like the way the aircraft flies in the 3D/freestyle mode this way.
We at JTEC Radiowave hope that you enjoy owning and flying your 3.2m Extra 330L or 300 ARF
far into the future.
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