Hobbico Spectrum User manual

90-DAY LIMITED WARRANTY
If you, as the original owner of this model, discover defects in parts and workmanship within 90-days of purchase, Hobbico will repair or replace
it - at the option of our authorized U.S. repair facility, Hobby Services - without charge. Our liability does not include the cost of shipping to us.
However, Hobby Services will pay shipping expenses to return your model to you. You must provide proof of purchase, such as your original
purchase invoice or receipt, for your model’s warranty to be honored. This warranty does not apply to damage or defects caused by misuse or
improper assembly, service or shipment. Modifications, alterations or repair by anyone other than Hobby Services voids this warranty. We are
sorry, but we cannot be responsible for crash damage and/or resulting loss of kits, engines, accessories, etc.
Your Spectrum ARF must be returned directly to Hobby Services for warranty work. The address is: Hobby Services, Attn: Service Department,
1610 Interstate Drive, Champaign, IL 61822-1067. Phone: [phone]. Please follow the instructions below when returning your model. This
will help our experienced technicians to repair and return it as quickly as possible.
1. ALWAYS return your entire system, including airplane and radio.
2. Disconnect the receiver battery switch harness and make sure that the transmitter is turned off. Disconnect all batteries and drain all fuel.
3. Include a list of all items returned and a THROUGH, written explanation of the problem and service needed. If you expect the repair to be
covered under warranty, also include your proof of purchase.
4. Include your full return address and a phone number where you can be reached during the day.
if your model is past the 90-day warranty period or is excluded from warranty coverage, you can still receive repair service through Hobby
Services
at a nominal cost. Repair charges and postage may be prepaid or billed COD. Additional postage charges will be applied for non- warranty returns.
All repairs shipped outside the United States must be prepaid in U.S. funds only. All pictures, descriptions and specifications found in this
instruction manual and on the product package are subject to change without notice. Hobbico maintains no responsibility for inadvertent errors.
ASSEMBLY INSTRUCTIONS
© Copyright 2000 HCAZ3008 for HCAA2615 V1.1

2
Take a moment now to
match the box contents
with the items listed
below. Following the
Spectrum assembly
instructions will be
quite
easy if you
identify and
organize the parts
before you begin.
Replacement Parts Available
HCAA3710...Wing Kit HCAA3714....Canopy
HCAA3711 ...Fuselage Kit HCAA3715....Landing Gear Set
HCAA3712...Fin Set HCAA3716....Spinner
HCAA3713...Cowl
Landing Gear
Part # Quantity
5 Landing Gear Blocks.................2
6 Landing Gear Struts (L&R) .......2
7 Wheels ......................................2
8 Tail Wheel..................................1
9 Landing Gear Cover Plates.......2
10 Plastic Gear Cover....................2
Wing Assembly
Part # Quantity
11 Wing Joiner..............................................1
12 Right Wing Panel .....................................1
13 Left Wing Panel .......................................1
14 Wing Bolt Plate ........................................1
15 Aileron Servo Covers...............................2
16 Retract Wheel Wells ................................2
17 Wing Mounting Plate................................1
18 Aileron Servo Tray ...................................2
19 Front Root Ribs........................................2
20 Rear Root Ribs ........................................2
* Clevises ...................................................2
* 4 x 35mm Bolt..........................................2
* 4mm Washer............................................2
18
14
Clevis
4mm
Washer
You’re about to build in just hours what took aviation
pioneers years—a powered machine that flies. Specially
created for you and other experienced radio control
modelers, Hobbico’s Spectrum offers nearly all the
excitement of piloting a real airplane...and develops skills
that will take you anywhere you want in your hobby.
*Parts marked with an asterisk are found on the plastic parts tree.
Know Your Model’s Parts
Engine Mounting Parts
Part # Quantity
1 Engine Mount ....................................1
2 Pushrod Tubes ..................................2
3 Pushrod Wire.....................................2
4 Pushrod Tubes ..................................2
4 x 35mm
Bolt

3
Tail Assembly
Part # Quantity
23 Stabilizer and Elevator ..................1
24 Rudder and Fin .............................1
* Control Horns .................................2
* 2mm x 18mm Machine Screws ......4
* Clevises.........................................3
* Pushrod.........................................2
Clevis
2 x 18mm
Machine Screw
Fuse Parts
Part # Quantity
25 Fuselage............................................1
26 Stab Base ..........................................1
27 Lower Wing Fairing ...........................1
28 Spinner ..............................................1
29 Cowl Decal ........................................2
30 Engine Mount Spacers ......................2
31 Cowl Side (L).....................................1
32 Cowl Side (R) ....................................1
33 Cowl Top............................................1
34 Pilot....................................................1
35 Tuned Pipe Mount .............................1
3
3
24
27
25
23
11
26
20
34
19
29
35
28
33 31
32
21
13
10
17
30
30
16
15
18
12
22 13
5
4
6
8
9
14
2
1
Parts shown smaller than actual size (out of proportion).
Fuel Tank & Parts
• Parts Shown Below
Part # Quantity
21 Fuel Tank ...........................................1
22 Foam Fuel Tank Collar.......................2
* 3 x 18mm Screw ................................1
* Silicone Fuel Line...............................1
* Plastic Stopper Compression Disks
(One Large and One Small)...............2
* Fuel Pick-up Weight (Clunk) ..............1
* Rubber Tank Stopper.........................1
* Aluminum Fuel Tubing
(One Short and One Long) ................2
7
Plastic
Parts Tree
Plastic Stopper
Compression
Disks
Pushrod
Rubber Tank
Stopper
Silicone Fuel Line
Aluminum
Fuel Tubing
Clunk
3 x18mm
Screw
Foam Tank
Collar
Control
Horns

4
Getting Ready for Flight
1. While building your Spectrum, make sure to follow the instructions. Do not alter or modify the model, as doing so may result in an unsafe or
unflyable model. In a few cases the instructions differ slightly from the photos. In those instances the instructions are correct.
2. You must install all components so the model operates on the ground as well as in the air.
3. You must check the operation of the model before EVERY flight to ensure all equipment is operating, and the model has remained structurally
sound. Be sure to check the clevises and other connectors often and replace them if they show signs of wear or fatigue
4. When you are preparing to go and fly your model, make sure to fully charge the radio system the night before, according to the manufacturer’s
instructions. Fully prepare your field box, making sure you have the necessary items for starting your engine. Remember to take along spare
propellers and glow plugs, as well as some epoxy and CA glue, just in case. Being prepared at the field will make your flying experience much
more enjoyable.
Other Items You’ll Need:
Glues
Choose 6-minute and 30-minute epoxy, such as Great Planes®
Pro™Epoxy, which has been formulated especially for R/C model
building. Pro Epoxies offer a strong bond and a variety of curing
times suited for every step of assembly. You’ll also need a thin
instant-setting CA (cyanoacrylate), medium CA+, plus rubbing
alcohol for easy epoxy cleanup. Great Planes Pro Threadlocker is
also recommended to secure threaded fasteners.
Model Engine
Power your Spectrum with a hot 2-stroke such as an
O.S®. .46 FX, or SuperTigre®GS-45. If you prefer a
4-stroke, an O.S. FS-70 is an ideal choice. Your choice
of 2-stroke or 4-stroke will determine the location of the
throttle servo and throttle pushrod exit on the firewall,
so plan ahead.
Radio Equipment
In selecting a radio system for your Spectrum, you’ll need at least a
6-channel radio system with five standard servos. Many of the
6-channel radios offered include only four servos, so it may be
necessary to purchase an extra servo along with your radio system.
Unless you are planning to use a computer radio and mix the
throttle servos, you will also need a “Y” harness for your Spectrum.
The servos and receiver will be mounted on-board your model and
need to be cushioned from shock and vibration. One-half inch thick
foam rubber sheets (HCAQ1050) are available from your hobby
dealer for this purpose.
Hardware
Tools and accessories required for assembly include
a hobby knife; small and large Phillips screwdrivers;
needle nose pliers; drill with 1/16", 5/64", 3/32", 1/8",
11/64", and 7/32" bits; ruler; 2 feet of medium (3/32")
fuel tubing; and 150 to 200-grit sandpaper.
Other General Items Required
Epoxy Brushes (GPMR8062) Mixing Sticks (GPMR8055) Clothespins 1/4" Foam Rubber (HCAQ1050)
T-Pins (HCAR5150) Masking Tape String Felt-Tip Pen
Sanding Block Adjustable Wrench Paper Towels Builders Triangle Set (HCAR0480)
Plastic Wrap or Wax Paper Round Toothpicks Wire Cutter Thread Locking Compound
70% Isopropyl Alcohol Small Hobby Clamps Razor Saw

5
Your Hobbico Spectrum is not a toy, but rather
a sophisticated, working model that
functions
very much like an actual airplane. Because of its
realistic performance, the
Spectrum, if not
assembled and operated correctly, could
possibly cause injury to yourself or spectators
and damage property.
If this is your first low wing sport model, or
if you are uncomfortable in making the
initial flight of your Spectrum, it is
recommended that you get help from an
experienced, knowledgeable modeler with
your initial flights.
You may also want to contact the Academy of
Model Aeronautics (AMA), which has more
than 2,500 chartered clubs across the country.
Through the AMA, you should either be able to
locate a modeler nearby that can help, or at
least be able to phone one that can verbally
instruct you for any potential problems that
could occur. Contact the AMA at
the address or
phone number
below:
Academy of Model Aeronautics
5151 East Memorial Drive
Muncie, IN 47302
Office: [phone]
Toll Free: [phone]
Fax: [phone]
Internet:http://www.modelaircraft.org
Protect Your Model, Yourself & Others...
Follow This Important Safety Precaution
WARNING! This is not a Toy! Please follow these safety precautions:
Before you fly:
1. Make sure that no other fliers are using your radio
frequency.
2. Your radio transmitter must be the FIRST thing you
turn ON, and the LAST thing you turn OFF.
3. Double check all control surfaces.
4. Make sure that the transmitter & receiver batteries are
fully charged.
Fuel storage and care:
1. Do not smoke near your engine or fuel.
2. Store all engine fuel in a safe, cool, dry place, away
from children and pets. Model fuel will evaporate, so
make sure that you always store it with the
cap secure.
When starting and running your engine:
1. Always wear safety glasses.
2. Make certain that your glow plug clip is securely
attached to the glow plug and cannot pop off, possibly
falling into the spinning propeller.
3. Use a “chicken stick” or electric starter to start the
engine – NOT your fingers.
4. Make sure that the wires from your starter and glow
plug clip cannot become tangled with the spinning
propeller.
5. Do not stand at the side of the propeller when you
start or run the engine. Even at idle speed, the
spinning propeller will be nearly invisible.
6. If any engine adjustments are necessary, approach the
engine only from behind the spinning propeller.
JOIN THE AMA
0" 1" 2" 3" 4" 5"
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140
Inch Scale
Metric Scale

❏1. If you are planning to install retracts, remove
the wood from both wing panels for the retract
servo location. The wood has been partially precut
for exact location.
❏2. Test fit the plywood forward center rib and the
balsa aft center rib on the left wing panel. The ribs
should not protrude beyond the top and bottom of
the wing. The forward plywood rib will extend
beyond the leading edge of the wing. This
extension will lock the front of the wing into the
fuselage. Do not cut off the extension on the
plywood forward center rib. Use 30-minute
epoxy to glue the center ribs to the left wing panel.
Repeat this step for the right wing panel.
❏3. Draw a centerline on both sides of the wing
joiner. Test fit the wing joiner into both wing panels.
A snug fit is desirable. If the joiner does not fit
properly, lightly sand any uneven surfaces from the
joiner edges and sides. Note: The wing joiner has
a slight dihedral angle on one edge. This angle will
be on the bottom of the wing.
❏4. Test fit the wing halves with the wing joiner. If
necessary, sand any high spots on the root end of
the wing panels so there is no gap when you join
them. The top of the wing is flat, with the taper on
the bottom of the wing acting as dihedral. Because
of this, the wing can be joined with the top of the
wing laying flat on your work surface.
Note: The dihedral angle is established by the
angle of the root ribs and the dihedral brace. As
long as the wing halves fit together tightly, you will
have set the correct amount of dihedral.
Make a dry run of the following step without using
any glue so you will know how to clamp your wing
together.
❏5. Tape a piece of wax paper or plan protector
over your work surface. Thoroughly coat the joiner
pockets and the mating ends of both wing halves
with 30-minute epoxy. Set the wing halves aside
and proceed quickly. Coat all surfaces of one half
of the wing joiner with 30-minute epoxy and place
it in one of the wing halves. Coat the other half of
the joiner with 30-minute epoxy and join the other
wing. Use a piece of balsa or cardboard to wipe
away excess epoxy. Use masking tape to tightly
tape the wing together. Use a tissue dampened
with alcohol to wipe away any more epoxy that
oozes out of the wing, then set the wing aside. Do
not disturb the wing until the epoxy has fully cured.
Wing Assembly
6

❏1. Remove the upper fuselage and lower fuselage
pieces from the main fuselage. Set these aside in
a safe location for use later in the assembly of
your model.
❏2. Locate the three plywood wing mounting plates.
Separate them and sand off any rough edges. Drill a
7/32" [5.5mm] hole at the punch marks on the plates.
❏3. Glue the three plates together in a stack with
the shortest on the top. Make sure the holes and
front edges are lined up with each other and wipe
off any excess epoxy using a paper towel and
rubbing alcohol. Use clothes pins to clamp the
plates together while the epoxy cures.
❏4. Install the blind nuts into the holes from the
bottom side of the mounting plate. (The short plate
is on the top.) Gently press the blind nuts into
position with a pliers or vise. Secure the blind nuts
into position with a drop of CA on the flange and
prongs of the nuts. Care must be taken not to get
CA into the threads of the blind nuts.
❏5. Test fit the wing mounting plate into position. Once
satisfied with the fit, secure it using 6-minute epoxy.
❏6. Place the wing on the fuselage. Measure
from the aft center of the fuselage to one wing tip
and record the distance. Measure from the same
point to the opposite wing tip, and compare it to the
first measurement. If the measurements are not
the same, adjust the wing and re-measure until
they are equal. Place a mark on the wing so it can
be repositioned for the following step.
❏7. Insert the 4mm x 25mm wing bolts from the
under side of the wing mounting plate. The bolts
should slightly extend above the wing saddle so
they can lightly touch the wing when it is placed in
position. Paint the tips of the bolts with a slow
drying paint. Before the paint dries, place the wing
into the saddle, making sure it is in alignment.
Press the wing against the bolts so the paint transfers
onto the wing, marking the location of the bolts.
A=A
AA
Wing Installation
7

❏8. Drill a 11/64" [4.5mm] hole at each paint
mark. The drill should be perpendicular to the
bottom surface of the wing while drilling. The bolts
must thread into the blind nuts squarely.
❏9. Position the wing bolt plate onto the bottom
of the wing. The plate should be positioned to
equally cover both holes. Trace around the outside
of the plate using a felt-tip marker. Carefully
remove the covering from the wing where the plate
will be installed, making sure not to cut into the
underlying wood. Secure the wing bolt plate using
medium CA. Once the CA has cured, drill the plate
using a 11/64" [4.5mm] drill bit using the holes
drilled in the wing as a guide.
❏1. Place the two plywood engine mount spacers
behind the engine mount if you are using a
2-stroke engine. Use four 3mm x 20mm machine
screws to secure the engine mount to the firewall.
Blind nuts have already been installed in the
firewall for this purpose. (If you are using a 4- stroke
engine, the spacers are not required.) Coat the
firewall, engine mount spacer and all other bare
wood around the firewall with fuelproof paint or
30-minute epoxy thinned with alcohol. Fuelproof
other areas of bare wood in the fuselage that may
be exposed to fuel or engine exhaust such as the
fuel tank area and the front and back of the wing
saddle. Avoid getting epoxy in the threads of the
blind nuts in the back of the firewall.
❏2. Temporarily attach the engine mount plates
to the engine mount using four 3mm x 12mm
machine screws. Adjust the width of the plates to
fit the engine, leaving a 1/16" [1.5mm] gap
between the engine and plates. Tighten the screws
so you can mark the engine mounting holes
without moving the plates.
❏3. Position the engine on the engine mount
plates so the propeller thrust washer (or spinner
backplate) is 4-3/4" [121mm] ahead of the firewall.
Use a sharpened piece of wire to scribe the four
Engine Installation
8

engine mount holes onto the rails. Use a center
punch at the marks to prevent the drill bit from
wandering, then drill 1/8" [3.1mm] holes through
the plates. Be sure to hold the drill perpendicular to
the rails. If you have access to a drill press, this is
a good tool for this purpose. Use four 3mm x
14mm machine screws, four 3mm nuts and four
3mm lock washers to secure the engine to the
mount. Use threadlock on the nuts to prevent
loosening.
❏4. Use the four 3mm x 12mm machine screws
and four 3mm lock washers to secure the engine
mount plates to the engine mount. Use threadlock
on the nuts to prevent loosening.
❏5. There is a 9/64" [3.6mm] hole in the firewall
for the throttle pushrod. Depending on your engine
selection, you may drill a new 9/64" [3.6mm] hole
for better pushrod placement.
❏6. Roughen the outside surface of the 13-3/4"
[350mm] throttle pushrod tube with coarse grit
sandpaper. Insert the pushrod tube through the
hole in the firewall which is in line with the throttle
arm on your engine. Push it in until about 1/4"
[6mm] of the tube is left exposed forward on the
firewall. Use medium CA to glue the tube to the
firewall, but leave it free inside the fuselage until
the servos are installed.
Note: There are three holes in the fuel tank
stopper but not all of the holes go all the way
through and only two are used for this model. Do
not puncture the third hole in the stopper.
❏1. Push the two aluminum tubes through the
rubber stopper until 1/2" [13mm] protrudes from
the front of the stopper. You will need to puncture
the rubber stopper on the back to push the tubes
through. Slide the large cap onto the front of the
stopper, and the small cap onto the back. Push
one end of the silicone pickup tube all the way onto
the clunk, and the other end all the way onto the
short aluminum tube. Insert the stopper screw into
the center hole in the front cap, then screw it
through the stopper into the aft stopper cap. Just
start the threads in the aft cap or you won’t be able
to insert the stopper into the tank.
❏2. Bend the long aluminum (vent) tube upward
at about a 45-degree angle, being careful not to
Fuel Tank Installation
9

kink the tube. Test fit the stopper into the fuel tank.
The seam around the tank should be horizontal
and the stopper hole on the left as you look at the
front of the tank. By holding the tank up to the light
you will be able to see where the vent tube is, in
relation to the top of the tank. If necessary, bend
the vent tube to position it about 1/8" below the top
of the tank. When satisfied with the fit, make sure
the stopper is fully seated in the fuel tank. Tighten
the stopper screw until the plastic cap is indented
about 1/16". Doing so will lock the stopper into
position. Check the clunk and pickup tube to make
sure they move freely in the tank without binding or
stopping.
❏3. Locate the foam fuel tank collar and remove
the center portion. Install the collar to the front of
the fuel tank.
❏4. Before installing the tank, make sure the bent
vent tube points toward the top of the fuselage.
Apply a bead of 100% silicone sealer around the
sides of the rubber stopper and the front edge of
the fuel tank. Insert the tank fully into the tank
compartment while working the stopper into the
hole in the firewall. The silicone will seal the
opening and help hold the tank in position after it
has cured.
❏1. Locate the 1/8" [3mm] plywood stabilizer
mounting base and test fit to the fuselage. Lightly
sand the base if necessary to obtain a good fit.
Remove the base from the fuselage. Reinstall the
base using a generous amount of 30-minute
epoxy. Be sure there is enough epoxy to properly
secure the base to the fuselage. Remove any
excess epoxy from the outside of the fuselage with
a paper towel and rubbing alcohol.
❏2. Draw a centerline on the top of the horizontal
stabilizer (stab) from the aft edge to the leading
edge. Center the stab on the stab saddle using the
centerline, and slide it forward until the leading
Install the Tail Components
10