Tower Hobbies FUN 51 Instruction Manual

® ®

The Profile Alternative

.40-SIZE RADIO CONTROLLED MODEL AIRPLANE KIT

INSTRUCTION MANUAL

Wing Span: 44 in.

Wing Area: 627 sq. in. Weight: 3.5 lb.

Length: 34.5 in. Wing Loading: 13 oz./sq. ft.

Engine: .35 to .51 Radio: 4 ch./5 servos

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READ THROUGH THIS INSTRUCTION MANUAL FIRST. IT

CONTAINS IMPORTANT INSTRUCTIONS AND WARNINGS

CONCERNING THE BUILDING AND USE OF THIS MODEL.

WARRANTY

Tower Hobbies®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 Tower Hobbies’ liability exceed
the original cost of the purchased kit. Further, Tower Hobbies
reserves the right to change or modify this warranty without
notice.

In that Tower Hobbies 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 liability.

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 Tower Hobbies.

The Fun 51 is not a toy, but rather a sophisticated, working
model that functions very much like an actual airplane.

Because of its performance, the Fun 51, if not assembled and
operated correctly, could possibly cause injury to yourself or
spectators and damage property.

To make your R/C modeling experience totally enjoyable, we
recommend that you get experienced, knowledgeable help with
assembly and during your first flights. You’ll learn faster and

avoid risking your model before you’re truly ready to solo.

You can contact the national Academy of Model Aeronautics
(AMA), which has more than 2,500 chartered clubs across the
country. Through any one of them, instructor training programs
and insured newcomer training are available.

Contact the AMA at the address or toll-free phone number
below.

Academy of Model Aeronautics

5151 East Memorial Drive

Muncie, IN 47302-9252

Tele. [phone]

Fax [phone]

Web Site: HTTP://WWW.MODELAIRCRAFT.ORG

© Copyright 1999 Version 1.1

PRINTED IN USA FP51PO2

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Congratulations!

If you have been looking for a way to put the

FUN

back into
your Sunday flying, you have just found it. The FUN 51 is a
nimble little

profile hot-dogger

that assembles in only a few
hours and is easy on the budget. It does not require any special
building or flying skill - just a few hand tools and a little tail­dragger time. With its oversized control surfaces it turns, loops
and rolls in the blink of an eye. But the thick, high lift airfoil and
light wing loading allow the plane to slow

way

down for gentle
spot landings. If equipped with an engine like the Tower .40 it’s
possible to be airborne in a matter of feet, zip through three
rolls, loop on its own axis, and then go into the “hover” mode
while waiting for your buddies to get off the ground. What more
can we say? The Fun 51 maximizes fun for minimal cost and time!

ITEMS REQUIRED FOR COMPLETION

We strongly recommend using

Great Planes

®

and

Tower

accessories for all your modeling needs.

❍ 4 Channel radio with 5 servos and a Y-harness

(TOWJ40**) (TOWM4520 x 5)

❍ .35 - .51 2/S or .40 - .52 4/S engine (Tower .40 ABC ideal)
❍ 4 - 6 oz. Fuel tank (GPMQ4101) or (GPMQ4102)
❍ (2) 2-1/2" Wheels (GPMQ4223)
❍ 1" T ail wheel (GPMQ4241)
❍ (2) 3/32" Wheel collars (GPMQ4302)
❍ 12" Medium fuel tubing (GPMQ4131)

❍ (2) Rolls covering film (Top Flite

®

MonoKote®or

T ower T o werKote®)

❍ 1/4" Foam rubber (HCAQ1000)
❍ 2-1/4" Spinner (GPMQ4517 Red)

SUPPLIES

❍ 1 oz. Thin CA (GPMR6002)
❍ 1 oz. Medium CA (GPMR6008)
❍ 6-minute epoxy (TOWR3300)
❍ 30-minute epoxy (TOWR3350)
❍ Balsa filler (HCAR3401)
❍ Masking tape (GPMR1010)
❍Wax paper
❍ Isopropyl rubbing alcohol (70%)
❍ Microballoons (TOPR1090)

TOOLS

❍ Sanding block and sand paper (coarse, medium, fine)
❍ Hobby knife and #11 blades (TOWR1010) (TOWR1015)
❍ Single edge razor blades (TOWR1005)
❍ Razor saw
❍ Razor plane
❍ Electric drill
❍ Drill bits - 1/16",1/8", 5/32"
❍ Small Phillips and flat blade screwdrivers
❍ Pliers with wire cutter
❍ Sealing iron and heat gun (TOWR3250) (TOWR3200)
❍T-Pins (HCAR5150)
❍ Straightedge with scale

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ITEMS REQUIRED FOR COMPLETION ....................................................................4

SUPPLIES..................................................................................................................4

TOOLS......................................................................................................................4

DIE PATTERNS..........................................................................................................5

IMPORTANT BUILDING NOTES..............................................................................6

BUILD THE FUSELAGE, FIN & RUDDER ..................................................................7

BUILD THE HORIZONTAL STABILIZER & ELEVATORS..........................................11

BUILD THE WING & AILERONS.............................................................................12

FINAL ASSEMBL Y....................................................................................................19

BALANCE THE AIRPLANE LATERALL Y....................................................................20

COVERING & FINISHING......................................................................................20

Repairing surface dings .....................................................................................21

Final sanding .....................................................................................................21

Cover the structure with TowerKote™................................................................21

Recommended covering sequence ....................................................................21

FINAL HOOKUPS AND CHECKS............................................................................22

BALANCE YOUR MODEL .......................................................................................24

CONTROL SURFACE THROWS ..............................................................................25

PREFLIGHT.............................................................................................................26

Balance the prop...............................................................................................26

Charge the batteries..........................................................................................26

Ground check the model...................................................................................26

Range check your radio.....................................................................................26

SAFETY PRECAUTIONS..........................................................................................27

FLIGHT...................................................................................................................27

Takeoff...............................................................................................................28

Flying.................................................................................................................28

Landing .............................................................................................................28

TABLE OF CONTENTS

Inch Scale

0" 1" 2" 3" 4" 5" 6" 7"

0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180

Metric Scale

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Remember: Take your time and follow directions to end up with

a well-built model that is straight and true.

Please inspect all parts carefully before starting to build! If any
parts are missing, broken or defective, please call us at
[phone] (Outside the USA - [phone]) and we’ll
be glad to help. Or, you may send an e-mail to:

[e-mail]

IMPORTANT BUILDING NOTES

Unroll the plan sheets, then reroll the plans inside-out to make
them lie flat.

Sort through the sticks and sheets, grouping them by size.
Masking tape can be used to bundle matching sheets and sticks.
Using a felt tip or ball point pen, lightly write the part name or
size on each piece or bundle. Refer to the parts list and plans for
sizes and quantities. Use the die-cut patterns shown on page 5

to identify the die-cut parts and mark them before removing
them from the sheet. Save all scraps. If any of the die-cut parts
are difficult to remove, do not force them! Instead, cut around
the parts with a hobby knife or lightly sand the back of the sheet.
After removing the die-cut parts, use your sanding block to
lightly sand the edges to remove any die-cutting irregularities.

Work on a flat surface. Cover the plans with wax paper or Great
Planes Plan Protectors (GPMR6167). There are notes on the
plans that tell you what material to use to make each part.

When instructed to

test fit

parts, this means DO NOT USE GLUE
until you are satisfied that everything fits properly – THEN glue
the parts together when instructed to do so.

The easiest way to cut balsa sticks is with a single edge razor blade
or razor saw. Position the stick over the plan, mark its size and then
cut the part on a piece of scrap lumber. A modeling miter box
works well for cutting square corners and 45 degree gussets.

We, as the kit manufacturer, provide you with a top quality kit
and great instructions, but ultimately the quality and flyability
of your finished model depends on how you build it;
therefore, we cannot in any way guarantee the performance of
your completed model, and no representations are expressed
or implied as to the performance or safety of your completed
model.

DIE PATTERNS

BUILD THE FUSELAGE, FIN AND RUDDER

❍ (1) Punch out the plywood die-cut parts. Use 30-minute

epoxy to laminate the fuselage core, scoop frame, canopy frame
& hump strap pads together.

Note: The airfoil shape that you punched out of the fuselage
core will be used for the wing tips in step 14, of “Build The
Wing And Ailerons.” The front of the engine cut-out, as well as
the ellipse from the wing tips, is not needed during construction.
You may save these for later use as scrap.

❍ (2) Drill a 5/32" diameter hole through the laminated fuselage

core at the two landing gear center marks and also at the
balance point.

❍ (3) Using the 1/8" x 1/2" x 6" plywood engine doublers and

the aluminum landing gear struts, mark the area on the fuselage
core as shown. When installing the side sheeting, do NOT apply
glue to the areas you just marked. Be sure to mark both sides of
the assembly.

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❍ (4) Using a hump strap as a

template, drill four 1/16" diameter
holes through the two hump strap
pads. Set these pads aside for now.

Note: Use only one of the six 1/4" x 3/8" x 36" balsa sticks to
build the fin and rudder.

❍ (5) Pin the entire fuselage portion of the plan over your

building board and cover the plan with wax paper. Build the
fuselage and fin over the plan as shown. Glue the hump strap
pads to scrap balsa shims as shown. Without glue, use 1/4"
leftover balsa spacers to maintain stab slot width.

❍ (6) Build the rudder over the plan as shown.

❍ (7) Glue two 3/32" x 3" x 36" balsa sheets to one side of the

fuselage frame. Make sure that you do NOT glue the sheeting to
the areas that you marked in step 3. Trim the sheeting around

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the perimeter and the wing cutout. Use leftover balsa trimmed
from the aft end of the fuse to fill in the top of the canopy and
scoop area.

❍ (8) Take the fuselage off the building board. Drill 1/16"

diameter holes through the balsa sheeting using the four pilot
holes in each hump strap pad and the balance hole as guides.
Drill 5/32" holes through the balsa skin for the landing gear. These
will help you position the landing gear later. Refer to the plan for
the length of the stab slot and then measure and cut the opening.

❍ (9) Flip the fuselage over and sheet the open side using (2)

3/32" x 3" x 36" balsa sheets. Do not glue the marked areas from
step 3. Trim the perimeter and wing opening as you did in step 7.

❍ (10) Drill 1/16" diameter holes through the balsa sheeting using

only the rear two pilot holes in each hump strap pad and the
balance hole. Drill through the landing gear holes with a 5/32" bit.

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❍ (11) Using the engine mount doublers and a landing gear strut

as templates, mark the balsa to be trimmed from the unglued area
of the fuselage core. Mark both sides of the fuselage.

❍ (12) Trim the balsa from the unglued areas on both sides of

the fuselage. Use 30-minute epoxy to glue the plywood engine
doublers onto the plywood skeleton on both sides.

This completes the basic construction of the fuselage. Round the
perimeter and flat sand the sides. Put the fuselage aside for now
and move on to the horizontal stabilizer.

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