User manual | File

 2. Buying the Right Stuff ....... ..... 4
3, Miscellaneous Preliminaries ......- 13
4. Preliminary Radio Installation ....-- .15
5. Covering the Model ......... eee 28
6. Post-Covering Assembly .......... 35
7. Final Radio Installation ........... 41
8. Final Touches ................... 46
9. Building the Goldberg Eagle 2,
| Eagle 63, and Eaglet 50 .......—.-- 48
410. Building the Great Planes
PT-20 and PT-40 .......00.00000000 51
11. Building the Midwest Aero-Star 20
and Aero-Star 40 ......... 00000 55
12. Building the Royal-Air 20T and 40T ...58
13. Building the Top Flite Headmaster . 64
14. Useful Addresses ................ 68
PC. ES
© 1989 by John Carroll. All rights Teservad TOS, book ma
without written permission from the publisher 1
— (BUILDING YOUR FIRST
BY JOHN CARROLL
Main cover photo by Chuck Porter
Editor: Michael Emmerich
Assistant Editor: Marcia Stern
Art Director: Lawrence Luser
kALMBACH|dBOOKS
PIKES PEA RRARY DISTRICT
- : x vo
. ; © Cw Foros
A : : PT
E |
4" 4 i . F 7 ВЕ = ,
PP - | : ;
— - - TN - i
ET
r 5 5 *i 7 -
Te a |
ни
ri - -.
T
a
AY : E
; ETA -
2. 3
M LA -
À
y
A
1. Getting Started
10e roduced in part or in whole
, except in the case of brief quotations used in re-
views. Published by Kalmbach Publishing Co., 21027 Crossroads Circle, P. O. Box 1612, Waukesh'
WI 53187. Printed in U.S. A. Library of
Congress Catalog Card Number: 89-84727. ISBN: 0-89024-097
1. Getting started
Our first order of business is to de-
fine two terms. I'll call the construction
manual that comes with your kit THE
MANUAL to distinguish it from this
book, which I'll call THE BOOK.
The next order of business is to get
you an airplane kit. Any of the ones
covered in THE BOOK will do the job, but
before choosing one, read Chapter Two
(Buying the Right Stuff), which de-
scribes each airplane. Then visit a
hobby shop and buy your kit. While
you're there, it won't hurt to purchase a
copy of one of the popular radio control
magazines such as Model Aviation or
R/C Modeler. Resist the temptation to
buy anything else on your first visit.
Before leaving the shop ask how to
contact the local RC club. You'll need
its field and its instructors to learn to
fly.
Also, many hobby shops carry AMA
(Academy of Model Aeronautics) appli-
cation forms. Take one and join the
AMA. Membership provides a variety
of benefits, not the least of which is li-
ability insurance. If you can’t get an
AMA form at the hobby shop, turn to
the back of THE BOOK for the AMA's
address.
Take your kit home and open it up
but don't start cutting and gluing yet.
udy the plans and read THE MANUAL.
sine the kit itself and compare the
hardware and materials inside with
the lists in Chapter Two of THE BOOK
(Buying the Right Stuff). There's also a
chapter on your particular airplane, so
check that, too, for additional items
needed to build the kit.
Now make a shopping list of every-
thing you need that isn't included in
the kit or that you don't have around
the house, and go on a shopping binge.
Don't settle for substitutes. All the
items I've listed are readily available,
and if you start substituting, you may
have problems later. If one hobby shop
doesn’t stock an item, try another shop,
or the manufacturer, or one of the mail
order houses that advertise in model
magazines. Whatever you do, don’t get
talked into the wrong engine or the
wrong kind of radio system: Either can
waste your time and money and make
you hate model airplanes.
As you're gathering equipment, read
Chapter Three (Miscellaneous Prelimi-
naries), which discusses the work area
and tells you how to make a few simple
tools and how to assemble the fuel
tank. Once you've finished those tasks,
turn to the chapter on your airplane.
There you'll discover a section on con-
struction, which tells you how to per-
form operations that are not clearly ex-
plained in THE MANUAL, or that should
be performed differently. Where possi-
ble, I present these topics in the order
they appear in THE MANUAL. Read what
THE BOOK says on these subjects, then
commence framing the model, follow-
ing the instructions in THE MANUAL, ex-
cept where THE BOOK contradicts them.
FRAMING THE MODEL
If you're building an ARF kit (Al-
most Ready to Fly) all you do in the
The Midwest Aero-Star 20 (above left), Goldberg Eagle 63 (above), Great Planes PT-40
— (below), Goldberg Eaglet (bottom), and Royal-Air 40T (bottom left) are just some of the
radio contro! airplanes you can bulld with the help of this book. | built these planes for
“framing” stage is join the wing panels,
an operation THE BOOK covers in more
detail than THE MANUAL does. If you're
building a conventional kit, you'll con-
struct the wood framework and do
nothing else. Read the chapter on your
plane in THE BOOK -before beginning
each cónstruction step so you dont
miss anything. Whether your plane is
an ARF or a conventional kit, ignore
any instructions in THE MANUAL to cut
hinge slots, install hinges, or glue the
tail parts to the fuselage. Life's much
simpler if you do those things later,
and differently.
After framing the conventional model
or joining the wings on your ARF, turn
to Chapter Four (Preliminary Radio In-
stallation). From this point on, just fol-
low THE BOOK, which will occasionally
refer you to THE MANUAL. When you
complete Chapter Eight (Final Touches)
charge the batteries overnight, then
take the plane to the field and have
your instructor check it to be sure you
did not make any serious mistakes.
Then fire up the engine and pretend to
be cool as you watch the model bounce
down the runway and climb out on its
maiden flight.
Before we get started, here are a cou-
ple of cautions:
1) Some kits can be built without ai-
lerons, but having taught RC flying for
many years, I don’t think that's a good
idea. Aileron airplanes fly more pre-
cisely, and provided they're properly
set up, allow you to learn more quickly.
I’ve written THE BOOK assuming you'll
build an aileron model. If you leave the
this book and kept careful notes as | went along, which appear in the final five chapters.
ailerons off, some of the things I tell
you to do will be wrong for your air-
plane. Build the ailerons.
2) RC flying is a fast-changing hobby,
and manufacturers frequentiy modify
kits and manuals. If something you
ST FE
NS Pa | oF po в PEE
Hee a ON С 1 . Я a Е
РАЕН От, ane à ACTO hot PRANTL
MALA OREA DE es Ei
#" DE se ый À
Ч | Ш E... E В LA a
: =
read in THE BOOK makes no sense,
chances are THE MANUAL or the kit has
changed since I wrote THE BOOK. Use
common sense in these situations. Dor
do something that seems crazy just
cause | tell you to.
Fig. 2-1. A few of the better trainer kits.
adams La Pi
ps > Shad
a AME
Ue vn. 113 PA A Ea,
2. Buying the right stuff
Hobby shops offer a mountain of ra-
dio control airplane equipment and
tools. Some of it is for you; lots of it
isn’t, at least not for now. This chapter
will help you decide what is and isn’t
for you.
THE AIRPLANE
If you're like most people getting into
radio control modeling, you have vi-
gions of yourself flying a scale P-51
TABLE 1: WING LOADINGS
— Plane wing loading (0unces/square
- fee)
- Eagle216.9
… PT-20 17.0
- Royal 40T 17.1
… Eagle 63 17.5
+ Aero-Star 40 17.9
… PT-40 18.6
-. Headmaster 18.6°
Eaglet 50 19.2
Aero-Star 20 19.8
Royal 20T 21.1
* Because of its symmetrical airfoil
the Headmaster is noticeably faster
than other trainers of the same wing
loading.
Вы.
Mustang or a biplane, or even a jet.
There's no reason you can't eventually
do all those things, but nobody starts
that way. Even if you make a living fly-
ing fighter jets, a gentle radio control
trainer will be a handful in the begin-
ning. Whoever you are, you'll need a
nice, stable, slow airplane to learn on.
One of the best ways to identify a
good trainer plane is to check its wing
loading — the weight supported by each
square foot of wing area. The lower this
number, the more gently the plane flies,
and the easier it is for a beginner to han-
dle. Table 1 lists the wing loadings of
the planes I built for this book. You
may get slightly different values, but
these will give you a rough idea of what
to expect from each kit. The best train-
ers have wing loadings below 18 ounces
per square foot. Notice that only one
small airplane made the cut. In this
hobby, bigger is almost always better.
Not all kits look alike when you open
the box. The conventional ones start
out as small piles of lumber (see Fig. 2-4)
while ARF (Almost Ready To Fly) kits
are framed and covered at the factory
(see Fig. 2-5). If you have the time and
enjoy building, get a conventional kit.
If you're short of time, you can buy an
ARF and get into the air with half the
work or less.
Most of the models discussed here
come in large and small sizes (see Fig.
2-6). If there’s room in your house and
car, get one of the big ones. It will be
much easier to see and probably will
have a lighter wing loading. The fol-
lowing paragraphs should give you
some idea of what to expect from each
airplane. If I seem to go heavy on the
superlatives, it’s because I chose only
the best models I know. Some terrible
dogs are out there masquerading as
trainers, but you won't find them here.
Conventional Planes
Goldberg Eaglet, Eagle 63, and Ea-
gle 2: This basic design has been
around for quite a few years because
it's good. The Eaglet is the small ver-
sion; the Eagle 63 (see Fig. 2-7) is the
outgoing larger version of the same de-
sign and is being replaced by the Eagle
2, which looks the same, but flies even
better.
The Eagle trainers are my favor-
ites — especially the Eagle 2. To my
eye they're the prettiest of the lot.
They're also light, easy to build, and
they fly well. I don’t know a trainer
that handles better than the Eagle 2.
Its takeoffs are smooth, there's al-
most no tendency to bounce on landing,
and the Eagle trainers are capable of
decent aerobatic performance. They
don’t perform outside loops as well as
some others, but they'll do inside loops,
Cuban eights, and even respectable
EE TW iy eg
EEE CEE th
ew. + И ИРИ A 2 od В © A,
x Mi Te ко po
TE
же к, я
Вс: os A
Figs. 2-2 and 2-3. These are good planes,
but not for the novice.
four-point rolls. The only bad rap on
the Eaglet 50 and Eagle 63 is that they
tend to pitch up too sharply when you
suddenly apply power. The Eagle 2
doesn't have that problem.
Fig. 2-6. These planes are both Midwest Aero-Stars, but be-
cause the larger Aero-Star (40) flies slower and is easier to see,
it’s a much better first airplane. In general, bigger trainers make
learning easier.
a, +
E.
Quthines AX Other R/C Trainers! -.
Atar + o See >
N
PES
== tél 2 Фыный
Fig. 2-5. ARF kits come out of the box already framed, covered, and decorated. They
take about half as long to build as conventional kits.
Great Planes PT-20 and PT-40: Both
of these planes are fun to fly because
once you've trimmed them properly
and have gained a couple of hundred
feet of altitude, they'll right them-
selves from any mess you get them into
(see Fig. 2-8). When I've allowed my
— PT-20 and PT-40 to take off on their
own, both have done fine. They'll al-
most land themselves smoothly — but
not quite. I've tried that a few times
and they've always flipped over. Of
course I had to line them up with the
runway before letting them land, and
the beginner doesn’t have a prayer of
doing that. Even with these stable
Fig. 2-7. This Goldberg Eagle 63 looks just like the newer Eagle 2
and the smaller Eaglet 50. All fly well, but the Eagle 2 is the bes’
Fig. 2-8. The Great Planes PT-40 shown here and the smaller PT-20 are among the easi-
est planes to fly because if you get in trouble and just let go of the controls, the plane
will right itself into a level glide. Then, if you add a little power, it will climb back to its
original altitude as if nothing had happened. If you have to start with a smaller model,
the PT-20 may be your best bet.
planes, you'll still need an instructor.
The PT planes pay a price for their
stability, though. They don't respond
as precisely as most trainers, and with
their large dihedral angles, they're eas-
ily blown over on takeoff or landing by
even a moderate crosswind. Regard-
less, they're the easiest four-channel
planes to fly. I'd especially recommend
them to anyone who has to learn RC
flying with little or no help from an in-
structor. (I'd also recommend you move
mountains to get help from someone
who knows how to fly rather than go it
alone. Teaching yourself is expensive,
frustrating, and potentially a hazard.)
Midwest Aero-Star 20 and Aero-
Star 40: This is another clean flying de-
sign. The smaller version is about as
fast as I like a trainer to get, but the
larger one is nice and slow and gentle.
Both fly well at altitude and handle
bumpy weather conditions better than
most trainers. Both take off nicely, but
my Aero-Star 20 (see Fig. 2-9) has a
tendency to bounce if I don’t hit the
landing just right. The Aero-Star 40
lands fine. THE MANUAL for both runs to
more than 100 pages and leaves little
room for error in framing the plane.
Fig. 2-10. The Royal-Air 40T is by far the easiest plane in this book to build. It's also
among the easiest to fly. The smaller 20T flies well, too, but noticeably faster.
6
The quality of the die-cutting on my
Aero-Stars was the best I've seen. I'd
rate the smaller version of this plane as
a good trainer and the larger one as
excellent. |
Almost Ready to Fly Models
Royal-Air 20T and Royal-Air 40T:
The Royal-Air 40T is the best ARF
trainer I've flown and the easiest plane
in this book to build (see Fig. 2-10). It
flies slowly, looks good, and has no bad
habits that I could detect. I'd rank its
flight performance with the best con-
ventionally built trainers. If you choose
an ARF, the 40T is probably your best
bet. The 20T also builds easily and flies
well, but it's faster than the 40T, and
like most small planes, isn't as forgiv-
ing of beginner error.
Top Flite Headmaster: 1 love my
Headmaster (see Fig. 2-11), mostly be-
cause it comfortably flies maneuvers
beginners shouldn't try — for example,
the old Figure-M with quarter rolls.
With its symmetrical airfoil it's fully
aerobatic, yet won't surprise you by
snap rolling just because you stall it. In
that sense it's an excellent trainer.
However, it's faster than most of the
airplanes covered here, so don’t buy
one unless you have a patient instruc-
tor who'll stay with you until you can
handle it. It will take longer to learn
the basics, but after you solo and gain
some confidence, the Headmaster will
be more fun to fly and will continue to
challenge you when other trainers leave
you bored. It's a good choice for teenage
pilots who learn faster than the over-20
crowd, or as a second plane for the non-
teenager.
THE ENGINE
Two popular kinds of engines are on
the market — the old reliable RC two-
stroker (make sure it's an RC engine
with a throttle, not a control-line en-
gine without one), and the popular
four-stroke engine (see Fig. 2-12). Buy
a two-stroker for your first plane. It's
reliable, simple to operate, and rela-
tively cheap. It gives you more power
for the weight, is less finicky than the
four-stroker, and probably is safer to
use. Your engine should come with a
muffler, and the muffler should have a
pressure fitting on it (see Fig. 2-13).
There is a variety of substitute muf-
flers, many of them worthless. Get the
equipment designed for your engine by
that engine’s manufacturer.
What Size?
Some kit manufacturers recommend
-engines that don't have enough power
for safe takeoffs, especially from grass
fields. You need enough power to pull
the plane off the ground with lots of ex-
tra speed. Takeoffs with underpowered
airplanes are touchy for the expert —
and much worse for the novice. The
chapter on your plane tells you what
Fig. 2-9. This Midwest Aero-Star 20 looks pretty and flies well,
but the larger Aero-Star 40 is more docile and easier to land
smoothly.
size engine you need. Don't use a small-
er one, no matter what THE MANUAL
says, and unless your field is at high al-
titude, don’t use one that is much
bigger.
An engine strong enough for good
grass field takeoffs is going to pull your
plane too fast if you leave the throttle
wide open after takeoff. Your instruc-
tor should teach you to throttle back on
reaching altitude. If he doesn't, remind
him. It's a lot easier to learn on a slow
plane than a rocket.
What Brand?
Its hard to recommend a specific
Fig. 2-12. Two-stroke glow engines like
this one are simple, cheap, powerful, and
easy to operate.
brand because manufacturers are al-
ways changing designs. If possible,
visit the club field and see what works
best there. Tve had good luck with
Supertigre, Fox, O. S., Royal, and K & В
but there are other good ones on the
market.
THE RADIO SYSTEM
This is the most expensive single
purchase you'll make, and the wrong
equipment here, no matter how cheap,
will lead to a catastrophe. That doesn't
mean you have to buy the top of the
line, but your system has to be appro-
priate to your needs. Here's what to
— Pressure tap
Fig. 2-11. The Top Flite Headmaster ARF flies circles around
most trainers because of its symmetrical airfoil. If you're older
than 18, however, it may be a little hot to learn on. it makes an
excellent second plane.
look for when you go to buy your radio:
1) 1991 certification: As of January
1991, more than twenty new “aircraft
only” frequencies will become legal.
This will reduce frequency separation
between adjacent 72 MHz RC channels
from 40 KHz to 20 KHz. To fly in this
environment, you'll be required by the
flying club to use narrow-band equip-
ment. If you don’t have it, you could
easily lose your plane, or worse, shoot
down someone else's plane. By the time
you read this book, all new radio sets
should be 1991 certified. Just be sure
you don’t buy a leftover that’s no longer
safe.
Fig. 2-13. The nipple on this muffler is a pressure tap. When you extend a line from the
tap to the fuel tank, fuel is forced to the carburetor, dramatically improving engine
reliability.
7
All controls neutral
except throttle,
which does not have
a neutral setting.
Throttle is shown
here haif open.
LEFT RUDDER
{Top view)
THROTTLE
Closed
THROTTLE
A Open
LEFT AILERON
(Rear view)
< |
UP ELEVATOR
Y
FIG. 2-15 MODE 2 TRANSMITTER CONTROLS
This is how the control functions are arranged on almost all U. 8. transmitters.
Left aileron is up; right aileron is down.
Pull stick toward body.
arrangement, buy a transmitter with this configuration.
© A”
RIGHT RUDDER
(Top view)
RIGHT AILERON
(Rear view)
Right aileron is up, left aileron is down.
DOWN ELEVATOR
Push stick away from body.
Unless your instructor uses another
Figs.
8
2.16 and 2-17. Both of these radio systems work well, but notice that one of them provides only three servos.
NERA IOI AE
В vil > * Ч
Fig. 2-14. For your first plane you're better
off with transmitters that use sticks.
2) Frequency choice: Before buying
a radio system, contact the club you'll
be flying with. Some clubs keep track
of who flies on what frequency and
steer newcomers to less-crowded chan-
nels. Club members also know which
channels are subject to local interfer-
ence, and whether the club prohibits
any legal frequencies at its field. The
clerk at the hobby store may or may
not be aware of all restrictions, but the
club people will know.
Unless you're a licensed amateur ra-
dio operator, you're restricted to 22
“aircraft only” frequencies on the 72-
MHz band. For convenience, legal fre-
quencies are designated by even chan-
nel numbers 12 through 56 (with chan-
nel 36 not used). These channels are
separated by 40 KHz. In January 1991
the odd-numbered channels 11 through
59 will become legal, reducing channel
separation to 20 KHz and requiring the
more selective “1991” receivers and
narrow-band “1991” transmitters.
Do not buy: 27-MHz equipment, it’s
subject to horrendous interference; 49-
MHz equipment, it gives insufficient
range; or any equipment on the “sur-
face only” 75-MHz frequencies, it’s
both illegal and dangerous to use in
aircraft.
3) At least four channels: The chan-
nels I'm talking about here are not the
frequency channels mentioned earlier,
but the control channels on the trans-
mitter and receiver. Each channel is
responsible for operating one servo,
and you'll need four of them: one each
for the elevator, rudder, throttle, and
ailerons. It’s possible to fly some planes
on fewer channels, but you'll need four
for your trainer and at least four for
most other planes. Four is the mini-
mum, but more won't hurt.
4) Two joysticks: Some transmitters
have a wheel instead of the joysticks
(see Fig. 2-14). That's fine if your in-
structor is comfortable with it, but use-
less if he isn’t. Most people use joy-
sticks, so you should start out that way.
5) Mode 2 stick configuration: Most
U.S. RC pilots ly Mode 2, so unless
These tools and a few more will get that plane built.
TABLE 2: TOOLS REQUIRED
[0 Pliers, needlenose
(3 Pliers, standard
(J Pliers, Z-bender
Prop wrench
Modeling knife, small
Razor blades, single edge (25)
T-pins, medium or small (100)
Soldering iron, pistol grip
File, flat
Sealing iron (you can use a small
flatiron, but it's not as good. If your
plane is an ARF, it's already covered
when you get it, but you'll need an iron
to take out wrinkles and to make
repairs).
O Vise, metal-working (you can use
this kind of vise for wood if you place
scrap plywood between the jaws and
the wood you're working with).
D Tape measure, steel, six foot
OO Paintbrush (Y:" or %"). This item is
optional. If you fuelproof exposed wood
with super glue or epoxy, you can get by
without it, but your plane will look better
if you paint bare wood.
(О Goldberg scriber (not absolutely
necessary, but worth getting. If you're
building a Goldberg kit, you atready
have one).
OO Drill, electric, capable of accepting
SAs” bit
OD Drill*bits, set of 13 ranging from Yıs"
to 7”. For some planes you'll also need
a %¢” bit. Buy top-quality drill bits, not
cheap ones.
CO Drill bit, long, Ya" diameter, 6” length.
000000
Available in hardware stores and some
hobby shops.
J Screwdriver, small
OO Screwdriver, medium
(0 Phillips head, small
O Phillips head, medium
O Straightedge, 18"
[] Straightedge, 48"
DO Drafting triangle or
carpenter's square
{J Coping saw or jigsaw
O Razor saw
J Penlight (not a necessity, but handy
for working in small, dark areas).
DO Ruler (you can use the 18” straight-
edge if it's graduated in inches).
OO Hex wrench set, containing sizes
0.05”, 710”, Ya”, and 3%". These wrenches
should be L shaped, rather than
straight, to fit into confined places.
771111
DO Sewing needle (or very fine pin)
OO C-clamps, 1” (4)
O C-clamps, 21" (2)
OJ Scissors
J Fine-tip felt marking pen
(J Fox prop reamer (you can survive
without one of these, but it’s handy).
A Ea
И ВЕ Pa Ч
IPC
Le
LE
Le ti
м Вы Во
a
Tale Cn wf ar
Pap
nié ich a J La Bede a ai a daté ae
Li
A]
a
A
Ro
OL
A
e PER IN
Bc le mele A ON
3
A
3
4
Clevis Control horn a CTT er
E Das iledinylon: prop
hreaded coupler connects. th throttle, cable to Me ihrotte cievia efi nreaded a | arg
shrods (right): Most models use only the partly threaded rods, but lf yous, | atever length you need tc
Rods you'll also use short, fully Hod bec ke.tha.ona shown harg.Dont vide just the: right amount of thr
EA um
IMA ий
1 PAE |
O ороООиННаця
1. Е
3 Sa
Ti
ot
= Nh vi ah of а ma ol | or Ve a brand
т ao or
1d ATT:
NON Kn e ES RINT
© во и pu USE o foleted. |
ang mts Nihal use The
rar RIAL р Sh De po ie о COS 3 NASA AN
= ' EAU - vus a | ie a A Li Ё | RANTS ОС я res Я
ok So A EE МЧ - e A re a voi Rae a NC ; ;
pe PME wr м
of AIRS BL -AlTE
Is non-irritating). -
soft grade 2 кое RARE will | aint those
- (J Balsa: shoot 0] Er 6”, medium parts with's color that matches ton let x your need any.
grade 14: BS “xy ments yoUF Color 8 ENTE ОА “are ‘available at the hobby
[J Balsa ‘sticks: It you' re bulla 0 по а.25 еп- [J;Polyurethane: pain Luc + E1210unces).-...Improvise. | often epoxy a.
gine or smaller plane, you need two sticks You'll only need: clèdf Pa nt. yout del: plane to balance It.
“ing tape. This tape is used between the may dissolve in the époi
PO NET
uses for this stuff, White ls
but us
The © larger wheel shown “hero ls a Dave
Brown Lite Flite wheel. It weighs much
U at
inner rod, which transmits’ control,
75 between servp and control surface.
re © used where a curved pushfo Pp
fit: “th
0 Cyano rylate (CA) glue;th
ting (4:ounces). Sold under various brand
names (Slow Jet, Super T; etc:;and the new
user-friendly; odorless “Hot Stuff, " „which
$ \Sandpepen: nea 150, e +
yourea ora proto mah |
8.150 grit: DUE Ht
O Accelerator : for CA glues (4 ounces): $6 finer paper after the |
also sold under various brand names, all of =- necessary... не 2, X O
which, as tar as | know, work on all CA = ={]-Heat-shrink covering film (2 folls tor .25-:--E Plywood sheet (1) 4" by'abOu
glues. = Poser erigine and smaller planes, 3 3 rolls for larger: “CiHardwood dowel (1), elthet EOF:
CO) s-minute epoxy glue (9 ounces) =“ 3+. ones) == not needed for ARF models.'1 rec- -. ameter and 3' long. Dowels should.
©) 30-minute epoxy glue (9 ounces); some ommend Coverite's Black Baron-films be-: + same diameter as the wing hotd-do
people are sensitive to epoxy glues. If | let it “cause they're easier to work with than most “els supplied In your КИ сей
sit on me too long, | get itchy skin and blis«:;:-and because they are available in attractive Gil 1: Waxed paper (1 box) +
ters (especially annoying if tinadvertentiy colors. Pactra Solarfilm is also easy to ap» Ll: Plastic sandwich bags (6)
rub my eyes and get blistered eyelids). 177 ply. CAUTION: Don't buy any covering ma- …. L].Rubbing alcohol (16 oui ces)
solved the problem by minimizing contact - terial before reading ‚Chapter. Five {Cover- cheapest clear (not colored) Kind
and by cleaning my hands almost immedi- “Ing the Model). 245%: A 24.15 4% "and don’t worry whether It's is 1
ately with a tissue soaked iri alcohol, fol- D. ‘Polyurethane palm ца ‘(Z'oùricés). -denatured ethyl; both worl
lowed by à thorough washing with soap. : du can get by without this if y Fuélproof. £3: Faclal tissues (1 box) :
OD Balsa sheet (1) "x 3" x 36", medium or exposed: WINECA O ore GE) Rubber bands (Y pound)
- * iL) Balance weights; don't]
“Foam rubber (1 sheet) 14°
va" square by 36" long, medium or hard uses stick-on. Seca you souk the «LJ: Thread (1 spool); aime
balsa. If you're building a larger plane, you decals in water, they are alre sady Tuelproot, “ton thread will do. If your pl
need two sticks %s" square by 36” long. +: so forget the ‘clear poh aretrianda % +. N-Rods#you don't need thi
(9 Acid-côre solder (1 smail:foil); use: the EJ Epoxy miking cups (36): USE зе Le Matte / Boards a bt
thin kind. Thick solder is hard to melt. 5% + paper cupsifwhich:iti imostmothir +465
OJ Silicone rubber glue (3 oiinces); comes the grocery store. YoU tara 150: hofd p es "CU
in several colors. Most people prefer clear. — in them, butriot rewtinner:T1 covering film - A
[J Seating tape (1 roll); also sold as mount- - paper cups on the: mes that some wax CI Velcro stri (47: x (24)
‘and weakèry pre handy for anchoring the rect
E - >teyto the e fuselage. В у
wing saddle and the wing and should be Joints. is ey
= = De AU
ЗН =
PA
a à
FV A SU ds
Fig. 2-18. Each of the small switches inside the back cover of this transmitter controls
the direction of rotation of one servo. If you install the rudder servo and discover that it
goes left when you give it right, simply flip the rudder servo reversing switch and all will
be well.
your instructor is the exception, that's
what you need to buy (see Fig. 2-15).
It's also what your dealer is most likely
to offer, but check to make sure.
6) At least four servos: Manufactur-
ers often sell four-channel systems
with only two or three servos (see Figs.
2-16 and 2-17). That makes for a low
apparent price, but you need all four
servos to fly. If you have to buy “ex-
tras” to get four, get the same kind that
came with your set.
7) Nicad batteries: Just about every
system now on the market comes with
rechargeable nickel/cadmium batter-
ies, but a few still come with old-fash-
ioned dry cells. Nicads cost more, but
you can recharge them hundreds of
times and each time you go to the field
you'll know you're starting with a full
charge. Conventional batteries need to
be replaced frequently, but since you
have no way of knowing when they're
low, you stand a good chance of crash-
ing because of battery failure. Even if
the conventional cells never fail you,
the cost of replacing them will drive
you to the poorhouse. Buy the Nicads.
8) Servo-reversing switches: Al-
most all transmitters come with servo-
reversing switches; make sure yours
does. They allow you to install the
servo without worrying whether it
turns clockwise or counterclockwise
(see Fig. 2-18). One important warn-
ing: If you ever fly more than one plane
from a particular transmitter, don't
forget to check the controls before take-
off. If you get airborne with reversed el-
evator or aileron controls, you will
crash — period — even if you immedi-
ately recognize the problem.
9) Buddy cord: On some radio sys-
tems it's possible to connect a student's
transmitter to an instructor's transmit-
ter by cable, allowing the instructor to
12
take control simply by lifting one fin-
ger from a switch. This saves the sec-
ond or two normally required for the
student to hand the transmitter to the
instructor when he gets into trouble.
That's a big advantage because in one
second, a diving, out-of-control model
can cover more than a hundred feet —
down. I've been an RC flight instructor
for many years, and I guarantee you
there's no better learning aid than the
old buddy box.
If you know an instructor whose
transmitter can be hooked to a buddy
cord, buy equipment compatible with
his. If you can't do that, it might be
worthwhile to buy a pair of transmit-
ters that will accept the buddy cord. I
feel that strongly about it, and I know
at least two novices who successfully
followed that route. The second trans-
mitter is expensive (you'll probably
have to buy the whole radio system),
but it won't cost as much as the plane
you may destroy without it, and it will
do wonders for your nerves when you
begin to make landing approaches.
10) Modulation: There are now three
kinds of modulation in common RC
use: Amplitude Modulation (AM), Fre-
quency Modulation (FM), and Pulse
Code Modulation (PCM). At our field
FM receivers are sometimes picking up
interference from AM transmitters, so
you're safer at our field with an AM
system. As 1991-certified equipment
takes over and the old wide-band trans-
mitters are phased out, however, this
should change. The industry seems to
be shifting to FM and PCM. PCM is
more interference-resistant than FM,
but also more expensive. The situation
is changing too fast for me to give any
advice that won't be wrong by the time
you read it. Your best bet is to visit the
club fiying field and find out whats
Fig. 2-19. The toggle switches on this
transmitter are dual-rate switches for rud-
der, aileron, and elevator. They allow you
to change the responsiveness of each
control electronically in flight. For the ex-
pert that allows smoother aerobatic per-
formance. The novice can use them to
dial in aileron control throw changes with-
out taking the wing off the plane. The only
caution is this: Even on low rate, you need
enough throw to fly the plane at low
speeds, where controls are less effective.
working well there before you buy any-
thing. Talk to a number of people.
11) Dual-rate switches: These will
allow you to adjust your control throws
electronically (see Fig. 2-19).
That covers the big purchases, but
you'll also need the tools, hardware,
and building materials in the tables on
pages 9-11 (on ARF kits you can skip
the covering material). There may also
be a short list in the chapter on your
plane covering items specific to that
plane. Check off what you already
have, then buy the rest. Table 2 lists
the tools you'll need. |
Table 3 lists the hardware and ma-
terials you'll need. It covers only items
that aren't supplied with every kit in-
cluded in THE BOOK. Your kit may con-
tain some of these items, so prepare an
inventory before you buy. In certain
cases the items listed here are intended
to replace items that are included with
your kit or radio system. For instance,
braided cables replace the solid steer-
ing and throttle pushrods supplied
with most kits, CA hinges replace kit
hinges, nylon clevises replace metal
ones, and the adjustable servo arm re-
places the fixed arm or wheel that
comes with your throttle servo.
And that’s it. Now you can turn to
the next chapter and start building.
LOT,
LE u
00 ны 2. 008 Re van a |
i. Вии
OF dd 20 ada
Fig. 3-1. A small area like this in your house or garage is all the room you'll need to work on your plane.
3. Miscellaneous preliminaries
Now that you've assembled the ma-
terials listed in the last chapter, you're
ready to begin building the plane — al-
most. There are a few other matters
you'll need to consider before you actu-
ally start building.
Fig. 3-2. The building surface can be any-
thing really flat that you can stick pins.
into. It doesn't have to be fancy, just ab-
solutely fiat.
THE BUILDING AREA
It's nice to have a big workshop with
every possible tool, but it isn't neces-
sary. The main requirements are an
out-of-the-way work area where you
can leave your partially built model
undisturbed between working sessions
and a flat working surface (see Fig. 3-1).
You'll also need decent overhead light-
ing. A small exhaust fan to carry glue
fumes out of the house wont hurt,
either.
I use a big, inexpensive plywood door
Fig. 3-3. Sanding tools like these will do
the job.
I bought at a lumberyard for the work-
ing surface (see Fig. 3-2). Other people
build on cork bulletin boards, or just
put Celotex or a similar material over a
flat tabletop.
HOMEMADE TOOLS
Some tools are not readily available
from hobby shops or are just easier and
less expensive to make yourself.
Sanding Tools
If you're building a conventional kit,
you'll need a few sanding blocks (see
Fig. 3-4. Make your reaming tool by filing
one end of pushrod wire to a blade.
13
- Vent line
Fuel line
Fig. 3-5. 1 cut this fuel tank apart to demonstrate properly arranged fuel and vent lines.
The weighted end (the clunk) of the fuel line is free to move and the vent line extends
into the molded bubble at the top of the tank.
Fig. 3-3). I make these from 1” balsa
sheet with coarse sandpaper on one
side and fine paper on the other. Glue
the sandpaper in place with CA glue. It
may look messy, but it works. For
starters, make two blocks, one 3" x 12”
and the other 2” x 4". Later you can
make special sanding tools as needed.
For instance, sandpaper glued around
a 4" hardwood dowel often comes in
handy.
Reaming Tool
This is a He” pushrod wire with a 90°
bend at the threaded end and a filed
blade at the other (see Fig. 3-4). Use it
to ream servo arm holes and drill holes
for elevator and rudder horn screws.
FUEL TANK ASSEMBLY
Assemble the fuel tank according to
the manufacturer’s instructions, but
don’t necessarily believe what they say
Fig. 3-9. lay the kit out on the bench,
—
14
about the length of the fuel line inside
the tank. If the assembled tank is held
vertical, the clunk should not touch the
bottom at any point, no matter what
the manufacturer says (see Fig. 3-5).
There are also two other important
things to keep in mind:
1) The stopper must be screwed
firmly in place so it can't be pulled out;
otherwise, the tank will leak. On the
other hand, don't tighten it too much or
you'll strip the nylon insert that holds
it in place — and the tank will leak.
2) You'll have to cut the metal fuel
lines if your tank has them and file
them smooth, as shown in Figs. 3-6 and
3-7. Check the plans, if any, to see
where to cut. If your plane is an ARF,
you can check by fitting the tank into
the plane itself.
With these preliminaries out of the
way, you can finally start building (see
Figs. 3-8, 3-9, and 3-10).
Figs. 3-6 and 3-7. Saw the metal lines,
then file them smooth. If you leave a jag-
ged edge, it will eventually cut the sili-
cone fuel tubing that fits over the lines
and cause all sorts of engine problems.
Fig. 3-10. and begin framing the model according to the instructions.
Ka >
Figs. 4-1 and 4-2. | rigged this servo to an ammeter to show how installed controls drain a bat-
tery. You can't see the transmitter, but in both cases it’s set for up elevator. The difference is
that in one photo I'm holding the servo wheel to stall the servo. This causes the servo to draw
enough current to drain the battery quickly — with disastrous results. Whatever else you do,
install the servos so they can’t stall in use.
4. Preliminary radio installation
THE MANUAL that comes with most
kits tells you to install the radio system
after everything else is completed, but
the experienced modeler makes a tem-
porary installation before covering the
airplane, and if possible, before plank-
ing the top of the fuselage. It's easier
that way, and if you make a mistake,
there's no need to: hack up your fin-
ished model to correct it. If you're
building an ARF, your model is already
covered, so you have to be more careful,
but the procedures are much the same.
Your job is to install the radio system
in such a way that: (1) the electronic
items within it are protected from vi-
bration; (2) all controls respond posi-
tively and exactly to transmitter com-
mands with minimum battery drain;
and (3) nothing comes apart or hangs
up in use (see Figs. 4-1 and 4-2).
Along the way, you’ll also install the
engine mount, the engine, and the nose
gear assembly. It will take at least sev-
eral nights to do all this, and then
you'll take everything apart again and
it'll look like you accomplished noth-
ing. Don’t be upset. The payoff comes
when you do an effortless final radio
installation.
THE SYSTEM
The on-board control system consists
of a receiver, a Nicad battery pack, four
servos, a switch harness, a number of
pushrods and control horns, and all the
odds and ends that tie them together
(see Fig. 4-3). In this chapter you'll
temporarily install these components,
except the switch harness and the aile-
ron servo, which are best left for later. I
will frequently refer to the transmitter
as the Tx and the receiver as the Rx.
PRELIMINARIES
First, charge all batteries overnight.
Next, hook up the Rx, battery, switch
harness, and all four servos according
to the radio manufacturer's instruc-
tions. Turn on the Rx and Tx and test
the system. I once skipped this step and
installed a radio that didn't work!
When you're sure the system is okay,
disconnect everything and lightly tape
about half an inch of foam rubber
around the Rx and battery as shown in
Fig. 4-4.
CHOOSING A SERVO TRAY
If you're building an ARF, use the
plywood servo tray provided in the kit.
On conventional models you have more
choices. Most radio sets come with a
plastic servo tray, which is perfectly
Switch
Charge jack
Battery
Receiver
| Servo ]
Servo
arm
Pushrod
&
Servo SIDE VIEW
Св
FIG. 4-3A THE ELECTRONIC COMPONENTS
FIG. 4-3B TYPICAL MECHANICAL COMPONENTS
| Servo ]
Elevator
Control arm
TOP
VIEW
Servo arm
15
Fig. 4-5. Here's a plastic servo tray.
=
Fig 4-4. You cover the whole battery except the leads, and ev-
erything on the receiver except the antenna and the servo lead
receptacle.
good provided it fits the geometry of
your installation (see Fig. 4-5). Many
kits provide plywood trays, which also
work fine, or you can cut your own from
Va" ply if necessary (see Fig. 4-6). Be-
fore you decide on a tray, check the ra-
dio drawing in the chapter on your
plane.
BEGINNING INSTALLATION
Slip rubber grommets into the mount-
ing lugs on each servo (and the plastic
tray if you use it), then press a metal
eyelet into each grommet to make sure
Fig. 4-8. The pilot holes for the servo-
mounting screws should be As".
16
Fig. 4-6. This plywood servo tray will also do the job.
Eyelets
(lip on underside)
Rubber grommets
Fig. 4-7. Eyelets hold the rubber grommets in place. The lip on
each eyelet goes on the underside of the grommet.
that it is fastened tightly (see Fig. 4-7).
Now install the servos in the tray. If
you use a plywood tray, mark and drill
pilot holes for the servo hold-down
screws as shown in Fig. 4-8, then screw
the servos in place. Make sure they
don’t touch any wood (see Fig. 4-9).
Your next step is to remove the ser-
vos from the tray and begin installing
the servo tray rails (if your plane uses
them) and the tray itself. Check the
Fig. 4-9. The servos must clear the tray by at least vs" all around. If they directly touch
chapter on your plane, and if there are
no comments on installing servo rails
or tray, follow THE MANUAL's instruc-
tions, keeping these points in mind:
1) Before gluing any rail or tray, test
fit the tray, the battery, and the Rx to
be sure there's space for everything
and that the rails and tray can be prop-
erly positioned relative to one another.
The servos must not touch the rails at
any point and the battery lead and an-
wood, engine vibration could cause the servos to fail.
Fig. 4-10. Mark a balsa stick at the bottom of the servo and make
a second mark %' beyond the first.
tenna must not be mashed against any-
thing hard. |
2) Before gluing any rail or tray in
place, measure to be sure the servos
will clear the highest obstruction on
the bottom of the fuselage by at least
Ye" (see Figs. 4-10 and 4-11). If they
won't, place the tray higher.
3) If you use a plywood. tray, I sug-
gest that for added security you epoxy
it in place, rather than fastening it
with wood screws. This makes install-
ing servos less convenient, but I think
it's a good trade off. If you use a plastic
tray, you'll have to screw it to the rails
as shown in Fig. 4-12,
4) Regardless of what THE MANUAL
says about gluing the rails or tray, use
epoxy, not CA. Epoxy seems to tolerate
vibration better.
5) If the rails just butt against the fu- 3
selage sides without any bracing, add
braces as shown in Fig. 4-13.
If you use a plywood tray, install the
servos after the glue on the tray sets. If
you use a plastic tray, install the ser-
vos, then screw the tray in place. Once
the servos are in place, you can move to
the front of the bird.
MOUNTING HARDWARE
TO THE FIRE WALL
On all the models covered here, the
nose gear bearing is bolted to the fire
wall. In some cases, so is the engine
mount. Follow THE MANUAL'S instruc-
tions for mounting them, with the fol-
lowing exceptions:
1) If your kit supplies ordinary hex :
nuts to hold anything to the fire wall,
replace them with blind nuts — some-
times called T-nuts in a few MANUALS.
(see Fig. 4-14).
2) If the fire wall for your kit has pre-
drilled holes for the throttle and steer-
ing pushrods, plug them with five-
minute epoxy (see Fig. 4-15). You'll
drill new holes later. Don't plug any
other pre-drilled holes. |
3) Cut all mounting bolts flush with
their blind nuts. Figures 4-16 and 4-17
show how.
Fig. 4-11. Measure to be sure the servo rail is higher than the
second mark when the end of the stick touches the fuselage
floor at its highest point.
Fig. 4-12. If you're using a plastic tray, use it as a guide to drill the rail’s mounting holes.
ENGINE MOUNTING
Alignment: Engine alignment is crit-
ical. Most trainers have a little built-in
right thrust. Make sure yours has the
amount shown on the plans. Whatever
you do, don’t build in left thrust or your
plane will be a monster on takeoffs.
If you end up with left thrust, do
whatever it takes, including cutting a
Fig. 4-13. The support braces should be
made from %" balsa
new breakaway plate, to get rid of it.
Mounting: The Royal-Air 20T and
40T contain special vise-like engine
mounts that allow you to install the en-
gine without drilling any holes. If you
are building either of these planes, re-
fer to THE MANUAL for mounting in-
structions as well as my discussion in
the chapter on them. If you are build-
ing any of the other planes covered
Fig. 4-14. Replace any hex nuts supplied
in your kit with blind nuts.
17
Fig. 4-15. Fill these holes in the fire wall
with five-minute epoxy.
here, you'll have to drill bolt holes in
the engine mount, which may be a
black, glass-filled nylon mount or a
wood breakaway plate. For the most
part, the instructions in THE MANUAL
are fine, If your engine mount is the
glass-fiber type and you intend to tap it
to take mounting bolts, follow the man-
ufacturer's instructions only; however,
if you're using a .40 or larger engine,
tap it for 6-32 bolts, rather than 4-40s.
If you don’t intend to tap your mount,
here's how to proceed. Install the prop
and spinner and position the engine so
Fig. 4-16. These bolts couid puncture the
fuel tank.
Fig. 4-18. Use
that the spinner backplate clears tre: ‘
front of the fuse or the plastic cowl 27:
Ye”. If your plane has a plastic cowl s: «
the instructions in THE MANUAL and i
the chapter on your plane for locatin
the engine on its mount.
Tack glue the engine in position witl
a couple of drops of CA, then, as showr.
in Fig. 4-18, use a long Ye" drill to make
the first hole in the mount. Install the ; . ANUAI
first mounting bolt, then drill the sec- , * e eng
ond hole, install the second bolt, and so
on until you get all four bolts installed.
This procedure guarantees that you
Fig. 4-20. Use cables inside nylon tubes like this instead of the solid wires supplied as
throttle and steering pushrods.
18
Fig. 4-17. ising a razor saw or similar tool,
cut the bolts so they are flush with the
blind nuts.
yt long 4" drill to drill bolt holes one at a time.
Fig. 4-19. An e i:ne bolted to breakaway plates. The plates
should be bolte +, ot screwed, to their bearers in the fuselage.
won't drill any holes in the wrong
place.
MOUNTING BREAKAWAY
PLATES
(Skip this section if your plane has a
glass-filled or metal mount.)
On some airplanes the engine is
‘ounted on a breakaway plate and THE
ANUAL alls you to attach the plate to
je ‘bearers with wood screws.
4. Use 4-40 machine screws
ki with blind nuts, because wood
— ewsarelikely to pull out of the wood
i ime (see Fig. 4-19).
HROTTLE AND NOSE
GEAR “PUSHRODS”
¿e pushrods that move the throttle
iz, ose gear should not be rods at all,
E -aided cables that slide inside ny-
k tes (see Fig. 4-20). Most kit man-
u. rers supply solid wires for this
jo) . t since these can rub or hang up
in . ‘the fuel tank compartment, I
rot. y throw them out and install
cab TN describe that installation
sho.: +.
Fig. 4-23. Rotate the steering arm against
the fire wall and insert & YA drill bit
through the connector hoie. Tap the bit
lightly to mark the fire wall. Then rotate
the steering arm out of the way and, using
your long %" drill bit, drill through the fire
wall at the mark.
FILING THE NOSE
GEAR STRUT
Before you can locate the hole for the
nose gear steering arm cable, you have
to install the nose gear strut and the
steering arm. The steering arm is
locked onto the strut with a setscrew
that has trouble getting a good bite on
the strut and tends to slip under pres-
sure (see Fig. 4-21). After a landing or
two, the plane no longer goes straight
with the rudder stick in neutral but
veers left or right.
To prevent the problem, file a flat
spot on the strut where the setscrew
will contact it (see Fig. 4-22). In a cou-
ple of kits, the flat spot is already filed.
Don’t make another one. The coil faces
the rear of the plane and the steering
arm makes an angle with the fire wall
when the nose gear is in the neutral
position.
LOCATING THE STEERING
CABLE HOLE
Once you've filed the flat spot, install
the strut through the bearing and
steering arm, tighten the setscrew, and
insert a pushrod connector in the outer-
most hole of the steering arm. Make
sure the arm and connector are on the
left side when the plane is right side
up.
If you're building a Royal 20T, see
the chapter on your plane for the loca-
tion of the steering cable hole. Figure
4-23 shows where it is on other planes.
DRILLING THE THROTTLE
CABLE HOLE
Now you need a hole for the throttle
cable. Figures 4-24, 4-25, and 4-26
show you how to drill it. If you've re-
moved the engine, re-install it with two
bolts, then pull the throttle arm on the
carburetor to the fully closed position.
You may have to adjust the throttle
stop setscrew (see Fig. 4-27). Next, line
up your long Ys' drill with the outer-
most throttle arm hole and drill a hole
Fig. 4-21. The steering arm is held in posi-
tion by a setscrew, which has a tendency
to slip on occasion.
Fig. 4-22. To prevent this slippage, file a
flat spot on the nose gear as shown here.
Align the file with the steering arm.
TI
Throttie arm hole
can be adjusted.
Throttle arm in fully closed position
Not all airplane/engine combinations allow you to position everything exactly
shown here, but the throttie cable must be no lower than the hole in the throttle arm |
hole ot the throttle will never close completely. if possible, adjust the throttie arm so ;
it reaches the same height in the fully open and closed positions. Most throttle arms
| æ
Fire wall АС. 4-24 IDEAL HEIGHT OF THROTTLE CABLE — F
Ш ©. HOLEIN FIRE WALL | $
\ 5 | Dotted lines; throttle arm in fully open position 5. : E | x
— 2°. - LORS
Co a En
o 2° E
a Er. A
Center throttle cable hole %” above hole О ER En
in throttle arm in fully closed position. EA
a
28:5.
in the fire wall approximately Ys" higher
than the throttle arm hole with the
throttle completely closed (see Fig. 4-25).
Aim the drill in the general direction of
the throttle servo arm inside the fuse-
lage. Make the angle between the drill
and the fire wall as close to 90* as possi-
ble, given that you have to miss the
fuel tank. When youre satisfied with
the position, drill the hole, then remove
the engine.
CABLE TUBING INSTALLATION
Insert a length of nylon tubing from
your cable set through the just-drilled
throttle cable hole and guide it to the
throttle servo. Use a razor blade to cut
the tubing about Y” in front of the fire
wall and 1%” in front of the throttle
servo arm. Repeat this operation for
the steering cable tubing (see Fig. 4-28).
(On the Royal 20T the steering cable ex-
its the bottom of the fuselage, not the
fire wall. Cut the tubing so that about
Y4" protrudes beneath the fuselage.)
Now glue both the steering and throt-
tle cable tubes to the fire wall (or fuse
bottom) with thin CA.
Follow this with thick CA and accel-
erator and cut the tube flush with the
fire wall or fuselage bottom.
FUELPROOFING THE
TANK COMPARTMENT
If your plane has a removable fuel
tank hatch cover, use thin CA glue to
19
Ty
©
° | Drill
ol `
7 A
E Z y |
/
Z. WARNING: DO NOT ;
FIG. 4-25 DRILLING THE THROTTLE CABLE HOLE | PUNCTURE FUEL TANK Long Y" drill bit
Aim the drill from the engine's throttle arm to as close as you can get to the throttie servo arm. You won't be
able to get a perfectly straight shot at the servo arm, so there will be some bend in the throttle cable as it
snakes around the fuel tank. Keep the band as gentle as possible. . | a
Throttle servo Receiver Battery pack Fuel tank
L
y | |
A
O O -
¿ aml 1
ee - ZZ
. - E“
+ Z 7
Ç L VA
A 7 7 7 N
FIG. 4-26 PATH OF THE THROTTLE CABLE Cable tubing Tinned cable ~ Pushrod connector on throttle arm
Throttle stop
setscrew
Fig. 4-27. The carburetor may not close
completely, but it will after an adjustment
to the throttle stop setscrew.
fuelproof the inside of the cover, the
rear of the fire wall, and the remainder
of the wood inside the compartment
(use a plastic bag to protect your hand).
Then use silicone rubber glue to attach
foam rubber to the rear of the fire wall
(see Fig. 4-29).
On a few planes you can’t get at the
fuel tank compartment, so forget about
fuelproofing it, but glue foam rubber to
the front of the tank with silicone glue
to protect the tank when you install it.
TEMPORARY FUEL TANK
INSTALLATION
Pad the tank compartment and the Fig. 4-29. Glue foam rubber to the rear of the fire wall to protect the fuel tank. It should
tank as shown in Figs. 4-30 and 4-31. It cover all the blind nuts.
20
FT
Fig. 4-30. Temporarily install and pad the
tank.
doesn’t matter exactly how you do it,
but make sure the tank is protected
from contact with everything except
foam rubber when you install it. On
most planes you can just slip the sili-
cone fuel lines through the holes in the
fire wall and connect them to the tank.
If your plane has a plastic hatch cover,
temporarily install it over the tank ac-
cording to instructions in the chapter
on your plane and THE MANUAL to be
sure it fits, then remove it. If your
plane does not have a tank compart-
ment hatch, check THE MANUAL on how
to install the tank. Otherwise, just
shove it in place. On some planes you
will have to trim the formers to make
room for both tank and foam.
INSTALLING BRAIDED CABLES
Alter the throttle and steering tubings
so they still lead to the proper servos
with the tank in place. Now connect
the battery and Rx to the switch har-
ness and plug each servo lead into the
appropriate receptacle in the Rx.
Fig. 4-31. Different planes require different approaches, but the idea is the same: The
tank should touch only foam rubber.
Cut with pliers two pieces of braided
cable, one for the throttle, one for the
steering. Each cable should be about
five inches longer than the tube into
which it will fit. Cut the wire cleanly
because even a little fraying makes the
following operations difficult.
You are about to solder some parts
and I suggest you wear safety glasses
because solder can spit at you. I also
suggest, based on painful experience,
that you not solder while barefoot.
Tin one end of each cable about 1%"
back. To do this, place the cable in a
vise as shown in Fig. 4-32. Hold a sol-
dering iron against the bottom of the
cable and a length of acid-core solder
against the top. When the solder melts,
it will flow into the wire braiding. Fig-
ures 4-33 and 4-34 show what to do
next.
Now pre-solder a threaded coupler.
Gently mountit in a vise, being careful
not to damage the threads, and apply
heat to the side while holding solder
against the opening (see Fig. 4-35). The
solder will melt and fill the hole.
Without removing the heat from the
side of the coupler, shove the tinned
throttle cable (make sure it's the throt-
tle cable) into the hole and continue
heating for a few more seconds. Then
remove the iron and let the joint cool.
Attach a nylon clevis to the throttle
cable's threaded coupler and a pushrod
connector to the nose gear cable (see
Fig. 4-36). Feed each cable through its
nylon tubing into the planes radio
compartment.
Attach the nose gear cable connector
to the steering arm without its plastic
retainer, move the nose gear to the
neutral position, and mark the cable
Y" to Y" aft of the center of the rudder
servo shaft with a fine-tip felt marker.
Remove the cable with the forward
pushrod connector still attached, cut it
at the mark, and tin the newly cut end.
Fig. 4-32. Two or three inches of the cable
should be sticking out.
Fig. 4-35. Soldering the threaded coupler
to the tinned cable. Don’t heat the solder
directly with the iron or you'll get a bad
joint.
Fig. 4-33. Use the hot iron to smooth out
any bumps, then remove the heat.
Fig. 4-34. When the solder cools, file the
tinned end smooth.
Fig. 4-36. Pushrod connector on the tinned steering cable; clevis on the threaded coupler
of the throttle cable.
21
Trim tab in
1" closed position
Trim tab in
-—
closed position
Trim tab in fuliy
open position
| | FIG. 4-37 PROPER THROTTLE SETUP
m closed position
Throttle stick in
~~ intermediate position
| _ Throttle stick in
1 Throttle stick in
tully open position
=D
—
Carburetor barrel ciosed
E—D
Carburetor barrel open a crack
EF
т
Carburetor barrel wide open
The solder should extend about 1%"
from the end. File the tinned area
smooth, then slip the cable back through
its tube. Attach the forward pushrod
connector to the steering arm with a
plastic or nylon retainer and tighten
the connector setscrew.
Slip a second pushrod connector over
the tinned end of the cable inside the
fuselage, but don’t tighten the set-
screw. Now remove the servo arm from
its servo, slip the connector into the in-
nermost hole it will fit, and clip the re-
tainer in place. Turn on the Rx and Tx,
set the rudder servo trim lever to the
neutral position, and install the servo
arm. Move the nose gear to neutral and
tighten the servo arm. Steady the cable
tubing with one hand; with the other
move the rudder stick left and right.
The nose gear should rotate clockwise
as viewed from the top of the plane
when you move the stick to the right. If
the gear turns the wrong way, flip the
servo reverser switch. Your first work-
ing control won't work positively until
later, when you brace the cable tubing.
THROTTLE CABLE
INSTALLATION
* The throttle cable is installed almost
the same way, but takes more tinker-
ing to get right. To minimize frustra-
22
tion, use an adjustable servo arm. At
this stage you just want to get the
throttle adjustment set roughly. You'll
fine-tune it during final radio installa-
tion, after installing the cable braces.
For now you can simulate a brace by
holding the cable steady with one hand
as you work the Tx with the other.
Your goal is to set things up so that:
1) fully closed throttle stick and fully
closed trim shut the engine off; 2) fully
closed throttle stick and intermediate
trim settings give a good idle; and 3)
full forward stick and full forward trim
give full throttle on the engine (see Fig.
4-37).
Remove the arm that comes with the
throttle servo. Again, temporarily in-
stall the engine. Slide the throttle ca-
ble into its tube through the fire wall
and connect the throttle cable clevis to
the throttle arm (see Fig. 4-38). Man-
ually push the throttle arm on the car-
buretor (not the servo) to the fully open
position. Then mark the cable about
one inch aft of the throttle servo.
Remove the cable, cut at the mark,
tin, file smooth, then re-install in the
airplane. Install a pushrod connector
on the newly tinned end of the cable,
slip the connector into an adjustable
servo arm, and fasten it in place with
the plastic retainer; however, you will
FIG. 4-39 ADJUSTABLE SERVO ARM IN
THE HALF-THROTTLE POSITION
Throttle servo
1 i J
Rudder servo
To nose
+ To tail
———
Elevator servo
(
A 4
With the transmitter stick and trim lever in
their middle positions, the throttle servo arm
should be perpendicular to the fuselage
sides.
Fig. 4-38. Connect the throttle cable clevis
to the throttle arm.
not install the servo arm at this point.
Set the carburetor barrel halfway
open, turn on the Rx and Tx, and set
the throttle stick and trim tab at their
halfway positions. Install the adjust-
able servo arm on the servo as shown in
Fig. 4-39. The cable should be near the
fuselage side. Tighten the connector
setscrew, then gingerly push the throt-
tle stick forward while holding the ca-
ble steady with your hand. This should
cause the barrel to open. If it closes, flip
the throttle servo reversing switch to
set it right.
You'll have to play around with the
length of the servo arm to obtain the
correct throw. At this point you'll just
want an approximate adjustment. This
is how to do it.
First, loosen the connector setscrew,
then move the throttle stick and trim
levers to the fully open positions. The
cable should slide through the connec-
tor as the servo moves. Make sure the
carburetor is fully open, then tighten
‘the setscrew on the servo arm connec-
tor. Now move the trim tab to the fully
closed position and hold the cable
steady with your hand as you gently
close the throttle.
If the servo stalls, back off, decrease
the servo arm length slightly and start
the adjustment process over. Figure 4-39
FIG. 4-40 ELEVATOR AND RUDDER PUSHRODS
HEADMASTER NOTE: You may have to
adjust the bend in the rud-
der pushrod on your plane
— to get an exact fit. Just
— make sure you get it to
work smoothly.
Fig. 4-41. Use Z-bender pliers to shape the wire.
FULL SIZE
LLLLLELLA
Fig. 4-42. Put the L of the rear pushrod wire into the hole this
way and glue it in place. |
Elevator
Rudder
Fig. 4-43. Coat the thread with thin CA. The other pushrod is pre-
pared the same way.
Fig. 4-44, Coax the pushrod out of its slot with a screwdriver.
23
shows the positions you're looking for.
Don’t be too picky at this point; save
that for final installation.
ELEVATOR AND RUDDER
PUSHRODS
The most secure way to connect a
servo to a pushrod is to use a Z-bend.
Unfortunately, you'll need special Z-
bender pliers to do this and it will cost
a few dollars. No matter; buy the thing
or borrow one. The Z-bend is good in-
surance. If you insist on using some
other technique to attach the elevator,
rudder, and aileron pushrods, you're on
your own. That said, here's how to
make and install the pushrods.
Draw front-to-rear center lines on
the top and bottom of the horizontal
stabilizer and use duct tape to fasten
the stab and elevator together. Tape
both sides of those surfaces. Do the
same with the fin and rudder.
The next step depends on whether
you use wood or nylon pushrods. Check
the chapter on your plane. If it says
“Gold-N-Rods” right under the chapter
title, skip the next section. If it doesn’t
you'll need wood pushrods, so read on.
INSTALLING WOOD
PUSHRODS
If youre building one of the ARF
models, don't use the already-made
pushrods. You can make better ones,
and after all this work, there's no point
risking your model on questionable
pushrods.
Begin by cutting the rear metal por-
tions of the pushrods to the exact shape
and length shown on the plans for your
plane. For ARF kits without plans, re-
fer to the full-size drawings in Fig. 4-40.
- After you've cut and shaped the rear
metal rods, you'll have a couple of
pieces of unthreaded wire left. If they re
long enough, you can use them for the
forward metal parts of the pushrods. If
they're not, or if its a close call, take
two new rods and cut off the threaded
portion. One way or another, you now
have two unthreaded pieces of wire. As
shown in Fig. 4-41, make a Z-bend in
one end of each and set both aside for
later use.
MAKING THE ELEVATOR
PUSHROD
Start with the pushrod material that
comes with your kit — unless you have
an ARF kit and I just told you to throw
that stuff out. If the wood part is hard-
wood, use it. If it’s soft, throw it out and
replace it. For planes with .25 or small-
er engines, use Y4'-square medium or
hard balsa. For larger planes, use %s"-
square balsa for the pushrods.
Drill a 7” hole about 144" from one
end of the wood rod, then make a slot
from the hole to the near end of the
pushrod. To make the slot, cut a thin
wedge with your razor blade, then use
the threaded end of a metal pushrod as
24
Fig. 4-45. Screw a clevis onto the pushrod so it can’t slip back in. Adjust the clevis until
the same amount of thread lies on either side of it.
Fig. 4-46. Connect a control horn to the pushrod.
a file to enlarge the slot. Trial fit the
metal portion by sinking the L of the
rear pushrod wire (the one threaded at
one end) into the hole as shown in Fig.
4-42. About one-third of the pushrod’s
diameter should stick out above the
wedge.
The L should not protrude from the
other side of the wooden rod. If it does,
remove the metal portion and cut off
just enough so it doesn’t. Now carve the
wood rod to shape, slip the metal por-
tion in place, wrap it with thread, and
secure with thin CA (see Fig. 4-43).
Once the CA has cured, thread the
pushrod through the fuselage from the
radio compartment. On some planes
the pushrod exits through the open
rear end of the fuselage. On some oth-
ers it exits through a slot in the fuse-
lage side. If your plane has a slot, move
the pushrod around until you can see
the threaded end through the slot, then
ease it out with a small screwdriver
and install a nylon clevis so it doesn’t
slip back in (see Figs. 4-44 and 4-45).
Then connect the clevis to the elevator
horn, which is not yet attached to the
elevator (see Fig. 4-46).
Now fit the horizontal stabilizer (stab)
onto its saddle (slot) and pin it in place.
Tape the horn to the elevator so the
clevis pin is even with the hinge line (see
Fig. 4-47). The base of the horn need not
be parallel to the hinge line, but it must
be aligned with the clevis (see Fig. 4-55).
Using the horn holes as guides, bore
screw holes through the elevator with
your reaming tool. Then, see Fig. 4-48.
Put the pushrod's forward end over
the elevator servo. Figure 4-49 shows
how. Locate one of the wires with a Z-
bend in it, remove the servo arm, and
insert the Z-bend (see Fig. 4-50).
Turn on the Rx and Tx, then replace
“the servo arm with the Z-bend in it.
Align the metal rod with the wood one
and mark the metal one 14" aft of the
mark on the wood rod using a fine-tip
felt pen. Remove the metal rod, cut it at
the mark, and bend a 4” L in it. The L
and Z-bend should lie in the same plane.
If they don’t, place one end of the rod in
a vise and twist the other end until
they do. Replace the servo arm with the
Z-bend in it and again align the metal
rod with the wood one. Press the L into
the wood to mark it.
Turn off the radio system, remove all
parts of the pushrod assembly (but not
the control horn), and cut the wood rod
where you marked it with the pen.
Drill a 4" hole where you marked it
with the metal rod, cut a wedge from
the hole to the near end of the wooden
rod, and attach the Z-bent rod with
thread and CA as before.
The elevator pushrod is now com-
plete. Install it to be sure it fits per-
fectly, and leave it in place as you
make and install the rudder pushrod,
which is done exactly the same way.
You can skip the next section and go
directly to the section on testing the
control system.
GOLD-N-ROD PUSHRODS
If your plane requires Sullivan Gold-
Fig. 4-47. Tape the control horn in posi-
tion, then use it as a guide to bore the
screw holes through the contro! surface
with your reaming tool.
N-Rods, here’s how to install them.
Your first step is to cut exit holes in the
fuselage sides. See the chapter on your
plane for the exact positions. As shown
in Fig. 4-51, I cut two sets of holes in
the PT-20. The first set went where THE
MANUAL said to put them. Unfortu-
nately, with the setup I used, those
holes didn’t work, so I had to cut the
second set. I simply plugged the extra
holes with scrap balsa before covering
the model. Had I not done a prelimi-
nary installation, the result would
have been a mess.
Having cut the exit holes, slip pieces
of outer Gold-N-Rod through them.
These should extend out the rear to
within two inches of the end of the fuse-
lage and forward into the fuselage to
within about an inch of the aft edges of
the rear servo cases. Glue the outer
rods in place at the tail with thin CA,
then reinforce the joints with five-
minute epoxy (see Fig. 4-52).
Slip inner rods into place and cut
them an inch longer than the outer
ones. Remove them from the fuselage
and screw one of the fully threaded
rods that come with your Gold-N-Rod
set into the inner elevator rod (see Fig.
4-53).
Starting from the tail, feed the inner
rod through the outer rod until it
emerges in the radio compartment.
Fig. 4-48. Put on the horn hold-down |
screws, but don't attach the backplate to Fig. 4-49. Mark the wood rod about one
the other side of the control surface. inch aft of the servo case.
Fig. 4-50. If necessary, ream the servo arm to accept the wire rod.
Fig. 4-51. Oops! | cut the first set of pushrod holes in the wrong places. Makes me glad |
did a preliminary radio installation.
Fig. 4-52. Here's a complete view of the Goid-N-Rod installation.
25
Fig. 4-54. Cut the rod and bend it as shown to make a handle so
you can screw it into the Gold-N-Rod.
Fig. 4-59. The Gold-N-Rods connected to servos and braced.
26
Ari Doria: 50
Le
ar E 4 oI
BE В
LI НЕ
Fig. 4-55. The front of the control horn need not be parallel to the
leading edge of the elevator, but it must be aligned with the
clevis.
Fig. 4-53. Screw a completely threaded
rod into the inner Gold-N-Rod to a depth
equal to about half its length or half an
inch. Then attach a clevis and clip it to a
control horn.
Fig. 4-56. Install the screws, but don’t in-
stall the horn backplate.
TTR va
CRE ES
Br peer
Align mark with
tooth shown by arrow
Fig. 4-57. To get the Z-bend in the right place, you have to set the mark on the rod over
the tooth identified by the arrow.
Now screw the threaded end of a partly
threaded metal rod into the nylon in-
ner rod inside the radio compartment.
You'll have to shorten the rod to do
this, then make a 90° bend at the un-
threaded end to use as a handle (see
Fig. 4-54).
Line up the elevator horn so that its
clevis holes are even with the elevator
hinge line and tape the horn in place.
Using the horn holes as guides, make
screw holes through the elevator with
your reaming tool (see Figs. 4-47, 4-55
and 4-56). Then, see Fig. 4-48.
Return to the radio compartment
and guide the partly threaded metal
pushrod over its servo arm and mark it
at the point where it will be connected.
Make a Z-bend there (see Fig. 4-57).
You will have to unscrew the rod to do
this. Now remove the elevator servo
arm. Connect the Z-bend to the servo
arm, then screw it back into the inner
Gold-N-Rod. Don’t attach the servo
arm to its servo yet.
Turn on the Rx and Tx, center the
trim tabs, and temporarily install the
servo arm on its servo. You'll probably
have to adjust the rod by screwing it in
or out before you can get the arm in its
proper position as shown in Fig. 4-58.
Once you've done that, screw the servo
arm in place. Now repeat the process
for the rudder pushrod.
Finally, install braces inside the fu-
selage to prevent the Gold-N-Rods from
flexing. To make a brace, drill a pair of
4" holes in Ya" x %" balsa scrap about
as long as the fuselage is wide. Position
the holes as shown in Fig. 4-59. Split
the brace lengthwise so you cut the
holes in half. Now epoxy the bottom
half of the brace into position with the
outer Gold-N-Rods sitting in the half-
holes, then glue the top half of the
brace over the bottom half as shown in
the Fig. 4-59. Brace the rods at each
former. If you don't, you're asking for a
crash.
FIG. 4-58 ADJUSTING LENGTH OF GOLOD-
N-ROD AT THE SERVO END
|
—
Screw the metal rod in or out as needed until .
the servo arm fits perpendicular to the fuse-
lage side as shown in B.
O) "
oa
nner rod
Outer rod
Elevator servo
TESTING THE CONTROL
SYSTEM
(Applies to both wood pushrods and
Gold-N-Rods)
Remove the tape from the right side
of the rudder/fin joint and the top side
of the elevator/stab joint. Turn on the
Rx and Tx and gently apply a touch of
down elevator and left rudder. If either
surface moves the wrong way, flip the
appropriate servo reverser to correct it.
Once you're sure of the direction, apply
full down elevator and full left rudder.
The control surfaces should move freely
and not interfere with one another. Re-
place the tape you removed and peel
the tape off the left side of the fin/rudder
and the bottom side of the stab/elevator.
Apply up elevator and right rudder. If
anything binds or otherwise causes
trouble, fix it now.
The preliminary radio installation is
complete. Remove everything that's
not glued to the plane, install any parts
you need to add before covering (e.g.
the fuselage top sheeting), and get
ready to cover your plane.
27
5. Covering the model
— If youre building one of the ARF
models, it's already covered and you
can skip this chapter. Otherwise you'll
have to cover the plane with an iron-on
plastic film.
When you open a roll of this stuff,
you'll find that the covering material
has a shiny outer side and a dull inner
side, and that stuck to the inner side is
a clear or translucent backing. To ap-
ply the covering, pull off the backing,
place the colored film glue-side down
on the model, and apply heat. The heat
melts the glue, allowing it to stick to
the wood beneath. That's the general
idea, but naturally there are details to
fill in.
CHOOSING THE COVERING
MATERIAL
If you choose Coverite's Black Baron
films, you'll find achieving a wrinkle-
free job with it is easier than with most
other brands. Black Baron has a lot of
shrink to it, which means it requires
only minimal skill to apply smoothly.
It also weighs less than most covering
films, which is a big plus.
THE COLOR SCHEME
If you're new to RC flying you proba-
28
bly don’t know how much influence the
plane’s color has on how well you can
fly it. That's right: Color affects flight
performance — significantly (see Fig.
5-1). Plenty of beginners crash because
they get disoriented. A sky-blue plane
against a blue sky is hard to see. A
white or gray plane against an overcast
sky tends to vanish — and crash. And
even experts have trouble with dark
blue and black planes. The easiest col-
ors to see are those that correspond to
the longest visible wavelengths. Bright
reds and oranges are best, and bright
yellows aren’t bad.
The problem isn’t just seeing the
plane, but figuring out what it’s doing.
If it's far out, as it will be most of the
time when you're learning, it's not ob-
vious whether it's coming or going; if
the top of the wing is one color and the
bottom another, you can sort things
out. The approximate rule is this: If
you see the color of the top of the wing,
the plane is turning toward you. If you
see the bottom color, it's either not
turning or is turning away from you.
So make the top of the wing and the
bottom two easily discernible colors. I
strongly recommend bright red or or-
ange on top and bright yellow on the
Top of wing is white, rest of plane is orange.
Plane is just above horizon.
—
Plane is banked left and turning toward you.
=
Plane is banked right and is turning
away from you.
FIG. 5-1 ORIENTATION AND COLOR
Fig. 5-2. This wing is not uncovered; it's
translucent orange on top and translucent
yellow on the bottom. In flight it's hard to
determine what the plane is doing.
Fig. 5-4. To cover imperfections, fill the
blemishes with plenty of vinyl spackle.
When it's dry, sand it smooth.
bottom. With that color scheme, a glint
of red or orange in the distance tells
you the plane’s turning for home, while
yellow tells you you'd best start giving
control inputs before it flies away.
Finally, let me caution you about
‘translucent colors. They look pretty up
close, but when the sun hits them, you
see neither the color of the top nor the
color of the bottom, but light reflected
by both top and bottom panels and light
filtered through both panels — which
won't tell you which side of the wing
you're seeing (see Fig. 5-2). Decorate
the fuselage and tail however you like,
but make the top of the wing a bright,
solid, easily seen color and the bottom a
different bright, solid color.
TOOLS AND TRICKS OF
THE TRADE
Your constant allies in covering the
plane will be lots of fresh razor blades,
a couple of matte boards, two straight-
edges (preferably 18” and 48”), and a
sealing iron. You'll also occasionally
use sharp scissors and facial tissues
(see Fig. 5-3).
CRIA a E U
Fig. 5-5. Cutting film with a straightedge and a razor blade. Usually you want film about
1” to 12” oversize in every dimension.
The matte boards are great cutting
boards. If you cut directly over your
workbench, not only will you scar it,
but the razor blade will follow the wood
grain, yielding a ragged cut which
causes trouble in some operations. If
you cut over the matte board, the razor
will follow the straightedge and give a
clean cut.
PREPARING THE WOOD
FOR COVERING
To achieve a pretty covering job, fill
imperfections with a material such as
DAP (a vinyl spackling formulation) or
a hobby product such as Model Magic.
Fig. 5-6. If the backing on the covering film
has an end piece, grip a loose end and
pull it off.
Figure 5-4 shows how to do it easily.
Whether you do this or not, you need
to sand the wood with fine sandpaper.
This creates lots of dust, which you'll
have to vacuum off before covering the .
model. | 5
PREPARING THE FILM FOR USE
To cut the film, lay it face down on
the matte board and place a straight-
edge over the line you want to cut. Put
a razor blade against the straightedge,
press the straightedge firmly against
the covering, and pull the blade along
the length of the cut (see Fig. 5-5).
The next trick is to remove the back-
Fig. 5-7. If there's no loose end, you'll
have to make one by roughing up a corner
of the backing with a razor blade.
29
Fig. 5-9. Smooth the covering with your hands, then tack it with a sealing iron at the
leading and trailing edges of both tips and at the center.
Fig. 5-11. Seal the film securely to the wood, making sure you always work toward the
open areas to avoid trapping any air bubbles.
30
ing. Figures 5-6 and 5-7 show how.
Caution: If you're not careful, the
film can twist around and stick to
itself when you remove the back-
ing, in which case you'll probably
have to throw it out. To avoid this,
don't pick the film up to separate
the backing. Leave it flat on the
cutting surface. As the backing
comes off, it creates enough stat-
Ic electricity to hold the covering
against the bench.
SETTING THE TRIM IRON
TEMPERATURE
Before covering any part of your
model, practice with scraps. You'll get
a feel for what you're doing, and you'll
have a chance to set the trim iron tem-
perature at the same time. If it’s too
cool, the film won't stick well. If it’s too
hot, the film will shrink too much and
wrinkle, or even melt. For starters, set
the iron in its middle range, wait about
three minutes, then try to iron a bit of
covering to a scrap of wood. You'll prob-
ably have to try two or three different
settings to get it right. And don’t get
complacent; the iron temperature can
change while you're using it, so if your
film misbehaves later, adjust the iron
temperature again.
CLEANING THE TRIM IRON
As you cover the model, especially as
you stick down the edges, colored glue
will cling to the iron; if you don’t get it
off, the glue will get on everything you
work with. Just rub it off the hot iron
with a dry facial tissue.
COVERING PRACTICE
If your model has a hatch cover, start
there so you won't waste much mate-
rial if you mess up. If there's no hatch
cover, a fin or rudder will do.
COVERING SOLID WOOD AREAS
With the aid of the following figures,
I'll cover a horizontal stabilizer to dem-
onstrate most of the techniques you'll
need to cover any solid structure.
First, cut the film to size with a razor
blade and a straightedge (see Fig. 5-8).
Remove the backing and lay the film
over the piece to be covered. Smooth
the film over the wood. Figure 5-9
shows what to do next. Then, iron the
center section. Don't use a lot of pres-
sure when ironing the center — if it
takes more than the weight of the iron,
increase the temperature. If the mate-
rial wrinkles a lot before you can iron it
down, the iron is too hot. With the cen-
ter section ironed in place, pull free the
tacked areas (see Fig. 5-10). Then be-
gin ironing from the center out toward
the tips and toward both the leading
and trailing edges. By ironing away
from the areas that are already stuck
down, you leave an escape route for air
that otherwise would be trapped, creat-
ing bubbles (see Fig. 5-11).
Fig. 5-12. Trim off most of the excess covering, leaving just enough to wrap around the
leading and trailing edges and the tips.
UA a
TD. A AL La
5 PI diet NEO nd
ARA AA LE
Fig. 5-15. Wrap the film around the leading and trailing edges and tips, but don't seal it
to the top of the stab. Trim off excess as shown.
Fig. 5-17. The finished stab shouid look like this.
With the covering smoothly ironed
onto the wood, turn the piece over and
trim off the excess film (see Fig. 5-12).
Don't iron the excess film to the wood
yet; first you'll have to cut the square
corners as shown in Fig. 5-13. On the
rounded parts, you'll need to slice the
filt. Figure 5-14 shows how. After
you've made these cuts, wrap the film
around the leading edge, trailing edge,
and tips with your trim iron, and use a
razor blade to slice off any excess (see
Fig. 5-15). Finally, go over all the loose
edges and seal them to the stab (see
Fig. 5-16).
Repeat the whole procedure to cover
the top of the stab and be sure to over-
lap the bottom covering all around by
about 4”. The seams should be just out
of sight underneath the stab. Seal ev-
ery bit of overlap to the first piece of
“film. This film-to-film contact, more
Fig. 5-18. To get rid of a bubble, puncture
it with a fine needie to let the air out. Then
touch up the spot with a hot trim iron.
than any film-to-wood contact, assures
you that wind and fuel won't rip the
covering off (see Fig. 5-17).
If you trap air bubbles under the cov-
ering, puncture them a few times with
a needle to let the air out and touch up
the spot with an iron (see Fig. 5-18).
Fig. 5-13. Cut out a little rectangle of film
at each square corner.
Fig. 5-14. Slice the covering every %- or
so for rounded corners.
Fig. 5-16. When you've sealed all loose
ends to the stab, all film should be at-
tached smoothly to wood.
When covering larger structures, no-
tably the fuselage, you’ll need several
pieces of film. For one thing, the fuse-
lage may be too long to cover in a single
piece. It's also a complicated shape
with curves in it (see Fig. 5-19). There
are three rules for covering with multi-
ple pieces: Rule One: Cover the bottom
first, then the top. This keeps the
seams as inconspicuous as possible.
Rule Two: Cover the rear first, then the
front. This allows the seams to face
away from the wind in flight. Rule
Three: Don't try to cover complicated
shapes with a single piece of film. It
doesn’t work (see Fig. 5-20).
COVERING OPEN FRAMEWORK
Covering the open framework of a
31
Fig. 5-19. For larger structures you'll need typically two pieces of film for the fuselage
bottom, two for each side, one for the top, and small pieces to fit the windshield, cowl,
and so on.
Fig. 5-20. The covering procedure for larger structures is the same, but work from the
bottom up and from the rear forward. Don’t try to cover any complicated shape with a
single piece of material.
Fig. 5-22. Cut a piece of material big enough for one wing panel, leaving a generous ex-
cess all around.
32
В E sn dd Sl DECI Ser de Epi as ES
TP AE
“La
o a
wing is more complicated. Start with
the bottom panel on one side (see Fig.
5-22). Cut a sheet of film at least 114"
oversize in every direction. Remove the
backing and lay the film glue-side
down over the framework. Position it so
the inner edge is about 4" beyond the
center and trim to fit the torque rod
(see Fig. 5-23). Smooth the covering
with both hands and tack the corners
with the trim iron. Now seal the center
section to the wood with your sealing
iron (see Fig. 5-25). Seal the covering at
the wing tip rib (see Fig. 5-24) and tack
it at quite a few points along the lead-
ing and trailing edges as shown in Fig.
5-26. Hold the film as you do this, but
don't pull it too tight. With the film
tacked and the center section firmly
ironed down, cut the film so it will fit
around the aileron indentations (see
Fig. 5-27).
Finally, seal the covering along the
leading and trailing edges. Trim off the
excess with the razor blade, and seal
loose ends to the wood (see Fig. 5-28).
Shrink out wrinkles by running the
sealing iron gently over them. Just
glide the iron, holding it so it barely
touches the film (see Fig. 5-29).
The second bottom wing panel is cov-
ered the same way with this exception:
After you have positioned the film,
smoothed it out, and tacked the cor-
Cover this area first
Fig. 5-21. Cover the area behind the
torque rod before you cover the whole
wing on this plane.
Fig. 5-23. Trim the center to fit around the
torque rod.
Fig. 5-25. Seal the center section to the
wood. Work outward to avoid trapping alr.
ners, you have to seal it where it over-
laps the first panel. Once you've fin-
ished this, you'll have to work from the
overlap out toward the leading edge,
trailing edge, and wing tip. Working
back toward the center will create air
bubbles.
The top wing surfaces are done much
the same way. However, a couple of
models don't have wood sheeting on the
upper center section. On these planes,
attach the film to the center section
spars and ribs as shown in Figs. 5-30
and 5-31. Note that excess film is
sealed to the side of the center rib. You
obviously can't do this with the second
top panel, so apply it the same way you
did the second bottom panel, just over-
lapping the first panel by Y” or so.
Ive shown you only a couple of
pieces, but the same techniques can be
adapted to covering the rest of the
airplane.
After you've flown the plane a few
times, you'll notice wrinkles cropping
up. Gently shrink the covering with
your trim iron to get rid of them.
Wing center
je g
NZ NN O
IN PAN IN
2 8 6 10 4
1 7 5 9 3
e NL SL NE
7 AN Ya
Leading edge of wing
!
|
|
i— End of wing center sheeting
|
|
FIG. 5-26 WING TACKING SEQUENCE
After tacking at the four corners, iron the covering to the center planking and tip rib, then tack the
leading and trailing edges in the order shown.
Fig. 5-24. Sealing the covering to the wing tip rib. Fig. 5-27. Seal the center area near the aileron indentation, then
cut the film as shown.
Le
E sila Til еЧРаНОЙ
Fig. 5-29. Glide the trim iron gently over the wrinkles to shrink
Fig. 5-28. Here's the covering sealed along the leading and trail- them out. You may need to raise the trim iron temperature a lit-
ing edges.
tle, but be careful not to melt the covering.
33
DECORATING
Trainers get banged up a lot, so you
don’t want to spend weeks decorating
your first one. However, a little strip-
ing to separate colors and a stripe or
two down the fuselage side can give
you a striking finish without a lot of
work. You can buy stick-on stripes in
various sizes and colors. Just make
sure they're fuelproof; not all are.
If youre willing to spend extra time,
you can make stripes from covering
film and iron them in place. I keep a
roll of black film around for just that
purpose. Cut the stripes with your long
straightedge over the matte board,
then just iron them in place.
Once the pieces are all covered and
striped, you can start putting every-
thing together to make an airplane,
which is the subject of the next chapter.
Fig. 5-30. If your plane has no top wing sheeting, cut the film on the center of the first top
panel as shown.
Fig. 5-31. Then, seal it to the center rib and spars.
34
Summum >
6. Post-covering assembly
Now all the pieces you've built will
start coming together to look like an
airplane. This is also the process of
seemingly endless odds and ends, all of
them important.
ATTACHING CONTROL HORNS
You've already bored holes in the el-
evator and rudder for the control horns.
Find the holes and insert the screws
through the horns and control surface
holes and screw the backplates in
place. Tighten firmly, but don't strip
the backplates. If you do strip one of
them, place a dab of five-minute epoxy
over the screw where it comes out of
the backplate. When it cures, the epoxy
should hold the screw in place (see Fig.
6-1).
HOLD-DOWN DOWEL
INSTALLATION
If the kit dowels are too short (see
Fig. 6-2), cut your own from hardwood
dowel stock of the same diameter as the
4 O
FIG. 6-1 INSTALLING CONTRO! ORN
a _— Backpiat
uu I —
Tighten screw firmly, but don't crush wood
or strip backplate. If you should strip one
backplate hole, coat the thread with epoxy.
as it emerges from the backplate.
dowels supplied in your kit. Round off
the ends slightly, position the dowels in
the fuselage, and glue them in place.
PAINTING AND FUELPROOFING
With the dowels installed, you can
fuelproof all the exposed wood parts —
with thin CA or paint (see Fig. 6-3).
Try to avoid getting paint into blind
nuts, but if you do, clear it out right
away by threading an amply greased
screw through the nut. Give the paint
at least 24 hours to cure (preferably a
few days) before subjecting it to pres-
sure from rubber bands on the dowels
or fuel from an operating engine.
Fig. 6-2. Make sure the wing dowels pro-
trude at least 74" from each side before
gluing them in place.
Fig. 6-3. Thin CA will do the job, but the plane will take on an
even prettier look if you brush on a polyurethane paint that com-
plements the covering color.
FUEL TANK INSTALLATION
Replace the fuel tank and its foam
rubber padding. The tank should touch
only foam rubber, not wood or metal.
Make sure there are no kinks in the
fuel lines. Finally, seal the area where
the fuel line passes through the fire
wall with silicone glue if that’s feasible
on your model (see Fig. 6-4).
LANDING GEAR INSTALLATION
Simply replace the nose gear bear-
ing, steering arm, nose gear strut, and
the main gear that you took off before
covering. When you install the nose
gear, also install the steering cable.
Tighten the steering arm pushrod con-
nector setscrew at this time. After the
engine goes in, you won't be able to get
atit.
ENGINE INSTALLATION
You've already had the engine in and
out of the airplane, but this time is for
keeps, so before you do anything else,
make sure all the screws and bolts in
the fire wall are good and tight. Then
do the same for all the screws and nuts
on the engine itself — especially the
screws that hold the backplate in place.
Then bolt the engine to its mount.
INSTALLING THE
HORIZONTAL STABILIZER
Ive provided two sets of instructions
for this operation. If you're building a
kit in which the stab sits on top of the
fuselage or underneath it, use the first
set (conventional kits). If the stab fits
into a slot, use the second set of instruc-
tions (ARF kits).
Glue here
Fig. 6-4. Sealing the fuel lines with silicone glue prevents fuel
from seeping into the tank compartment.
35
FIG. 6-5 ALIGNMENT MARKS ON FUSELAGE
Wing
— |
Forward
atignment
mark
Note:
for stabs that fit
into slots,
no rear align-
ment mark is
needed.
Stab platform
Note:
For plane on which
the stab is attached
to the underside of
the fuselage, the
rear alignment mark
also goes on the
underside.
Rear alignment mark
Conventional Kits
Start by making three alignment
marks with a ballpoint pen. (You can
erase these later with a tissue soaked
in alcohol.) The first mark goes dead
center on top of the fuse just behind the
wing saddle. The second mark goes
dead center just ahead of the stab plat-
form — on top of the fuse if the stab sits
on top, or beneath it if the stab sits be-
low the fuselage. Draw the third mark
on the stab itself, dead center at the
leading edge (see Fig. 6-3).
Once you've made the alignment
marks, pin the stab firmly in place so
that the center mark on the stab aligns
with the center mark just ahead of the
stab platform. Measure from each stab
tip to the workbench as shown in Fig.
6-6. Both measurements should be the
same. If they're different, remove the
stab and carefully sand the platform.
Be careful not to remove too much
wood, round the platform, or change
the angle at which the stab will meet
the air in flight. Pin the stab back in
place and repeat the measurements. If
need be, repeat the whole operation un-
til you get it right.
With the stab pinned in place and
Fig. 6-7. The distance from the alignment mark behind the wing saddle tc each rear stab
tip should be the same.
36
level, use your tape measure to mea-
sure from the alignment mark behind
the wing saddle to each rear corner of
the stab as shown in Fig. 6-7. If the
measurements are not the same, repo-
sition the stab and measure again.
When you've got it right, check to be
sure that the tips are still the same dis-
tance from the banch.
If the stab sits on top of the fuselage,
turn the plane over and use a ballpoint
pen to draw lines on the underside of
Fig. 6-6. The stab fips must be the same height above the bench.
the stab where it meets the fuselage on
the left and right (see Fig. 6-8). If the
stab fits beneath the fuselage, leave it
in place and draw the lines on the top
where it meets the fuselage.
Take away the stab and draw a sec-
ond set of lines (see Fig. 6-9). Cut the
covering along the inner set of lines
without cutting the wood beneath it
and strip off the center section of cover-
ing material. 2
Smear the stab platform and the
Fig. 6-8. Mark the stab on the left and right
sides where it meets the fuselage.
hi
£
}
Fig 6-10. if the stab sits crooked in its slot, sand or cut down the
high side to level it.
1 - sas PO
E O
: + i +
a
Fig. 6-11. A drafting triangle or a carpenter's square will help get
the fin vertical.
Wing
—
FIG. 6-12 SQUARING FIN WITH STABILIZER
A
Fin
Triangle
y Ф”
Place drafting triangle
on stabilizer as shown.
Adjust the fin so it's
parallel to the vertical
leg of the triangle.
Alternatively you can use
a carpenter's square.
Stabilizer
/ — /
Rear of fuselage
FIG. 6-13 ALIGNING THEFIN
A straightedge placed flat against the left side of the fin should miss the
forward alignment mark by the same amount as a straightedge placed
against the right side of the fin.
и Forward alignment
mas yd mark
и
Stabilizer
newly exposed wood on the stab with
30-minute epoxy, then use several pins
to attach the stab to the platform so the
center line is even with the mark
ahead of the stab and the lines on the
stab are flush with the fuselage on both
sides.
_ Wipe off excess epoxy with an alco-
hol-soaked tissue. Measure one last
time to be sure the stab is still aligned
and level. If there's a problem, make
adjustments before the epoxy cures. Set
the work aside while the glue dries.
ARF Models
This procedure is slightly different
from the one used on other planes be-
cause the stabs on the ARFs covered
here fit into slots rather than on top of
platforms.
If necessary, cut out the slot, then
slip the stab into it and measure to be
sure the length is the same on each
side. If it's not, adjust until it is. Then
measure to be sure both tips are the
same distance from the workbench (see
Fig. 6-10). Sanding or cutting the high
side of the stab to even it will leave a
gap at the top side of the slot that you'll
later have to fill with epoxy and balsa.
Make a mark with a ballpoint pen
dead center on the top of the fuselage
behind the wing saddle (see Fig. 6-5).
You can erase the mark later with a
tissue soaked in alcohol. Measure from
the mark to each rear corner of the
stab; the measurements should be the
same (see Fig., 6-7). If they aren't, ad-
just until they are. When you've done
this, pin the stab securely in place and
draw lines on the top and bottom on
both sides of the stab where it meets
the fuselage.
Remove the stab and draw a second
set of lines párallel to and 7" inside the
first sets. Cut the covering along the
inner lines without cutting the wood
beneath, then peel off the center cover-
ing section to expose the wood.
Smear 30-minute epoxy into the slot,
being sure to cover every bit of wood,
then smear epoxy over both the top and
bottom of the exposed wood on the stab.
Slip the stab into position and repeat
your measurements to be sure it's level
and lined up with the mark behind the
wing saddle. If it's not, adjust, then pin
it in place, wipe off excess epoxy with
an alcohol-soaked tissue, and check
your measurements one more time. Al-
low the epoxy to cure, then fill any gap
between the stabilizer and fuselage
with epoxy, or if it's a large gap, with
wood and epoxy.
FIN INSTALLATION
The critical part of installing the fin
is getting it lined up perfectly with the
fuselage center line. If you miss, the
37
lane may be impossible to trim for
straight and level flight under varying
speed conditions, so extra effort is in or-
der. It’s also important that the fin rest
upright on top of the fuselage, though
not as important as getting it lined up
on the center.
Before you start, make sure you can
locate any fin braces and that you've
already covered the parts of the braces
that will be exposed after the braces
are installed. Most trainers have a pre-
cut slot for the fin, but it's not always
accurately aligned. If yours is off a lit-
tle, you'll have to trim it to allow the
fin to line up properly. If your plane
has a slot, insert the fin and pin it in
place. If it doesn’t have a slot, just pin
the fin over the stab center line.
With the fin in position, use a draft-
ing triangle or a carpenter’s square
(see Fig. 6-11) to set it at a 90° angle to
the stab (see Fig. 6-12). On some planes
‘the fuselage sides prevent you from
holding the triangle against the fin and
stab at the same time. In such cases,
set the triangle on the stab as close to
the fin as you can and make sure the
distance between triangle and fin is the
same on both sides of the airplane.
Once the fin is vertical, place your
long straightedge flat along the left
side of the fin. The straightedge should
then fall slightly to the left of the align-
ment mark behind the wing saddle.
Mark the point as shown in Fig. 6-13,
then repeat the procedure on the right
side. You should now have a mark on
either side of the alignment mark and
the distance between the alignment
mark and each other mark should be
the same. If it’s not, adjust the fin and
repeat the measurements until it is,
trimming the slot if necessary to ac-
complish this.
PREPARING TO GLUE
THE FIN IN PLACE
Once the fin is aligned and pinned in
place, you need to draw lines to guide
you in removing covering so you'll get a
good wood-to-wood glue joint (see Fig.
6-14). If your fin fits into a slot and
doesn’t have a brace, mark the fin and
dorsal fin, if any, where they meet the
fuselage and/or stab. Now mark the fu-
selage where it meets the fin and dor-
sal fin. If your fin has no slot, just mark
the stab and fuselage top where they
meet the fin. If your fin has braces, pin
them in place and outline them on the
stab and fin.
Remove the fin and cut the covering
material on the fin, stab, and airplane
fuselage top about Ye" inside the outer-
- most line you drew. Don't cut the wood
below. Now strip off the covering mate-
rial inside the cuts.
- Cover all exposed wood parts on the
fin, dorsal fin, slot, stab, and braces
with 30-minute epoxy, pin the fin back
into position, and add the braces. Then
get your straightedge and triangle (or
38
Fig. 6-14. Mark areas of wood-to-wood
contact and strip off enough covering to
allow good glue joints.
`.. a
. ALT RON YORQUE ROD ue . Lo
Fig. 6-16. For conventional kits, mark
hinge locations over the plans.
Fig. 6-18. Here is how to insert the hinges
into the slots.
carpenter's square) and adjust until the
fin is perfectly aligned with the center
mark behind the wing saddle and sits
perpendicular to the stab. Once you've
got it right, leave the assembly alone
overnight until the epoxy's cured.
INSTALLING HINGES ON
FIN, STAB, AND WING
Start by drawing center lines on the
trailing edges of the wing, stab, and
fin, preferably using a Goldberg scriber
(see Fig. 6-15). Next, mark the location
of each hinge with a ballpoint pen. You
can erase the marks after the hinges
have been installed. Take the hinge lo-
cations from the full-size plans if your
kit supplies them (see Fig. 6-16). It's
important to get the hinges in just the
right places, especially if your plane’s
wing contains filler blocks designed to
give the hinge more wood to hang on to.
If your plane is an ARF with precut
slots or holes, don’t use them. Instead,
make new slots a little to one side of
them.
Fig. 6-15. A Goldberg scriber helps you
draw good center lines. | used a bare
piece of wood to demonstrate the tech-
nique because the camera didn't see it
well on covering material, but the tech-
nigue's the same.
Fig. 6-17. The hinge slot should be a little
deeper than half the hinge length and half
again as long as the hinge is wide.
Fig. 6-19. Here are the hinges glued in
place. Use only the thinnest, most irritat-
ing kind of CA glue.
Having located a hinge position, sim-
ply cut a slot with your modeling knife
as shown in Fig. 6-17. When you've cut
all the slots, insert a hinge halfway
into each one as shown in Fig. 6-18,
and put a drop or two of thin CA glue
on each side of the hinge at the slot. Do
not use thick CA or thin User Friendly
Odorless “Hot Stuff” for this job. They
don’t penetrate deep enough (see Fig.
6-19).
Make sure none of the CA leaks out
Fig. 6-21. Gluing the hinges. Be caretul not to let the CA run out
onto the covering.
Fig. 6-20. Slide the control surface over
the hinges. On this plane | glued the rud-
der in place first. On some planes, If you
do this, you won't be able to get the eleva-
tor on. Test fit the surfaces on your plane
betore you start gluing.
onto the main surface. The stuff loves
to run across a wing or tail and make a
permanent mess. Sop up any excess
with a dry facial tissue. Use capillary
action; don’t rub the tissue around, and
don’t let it get glued to the plane.
HINGING THE CONTROL
SURFACES
Cut slots in the rudder, elevator, and
ailerons. These slots should be about
twice as wide as the hinges so you can
move the control surface back and forth
to line it up properly. Install the eleva-
tor first. (On some planes if you do the
rudder first, you can’t get the elevator
on.) Do the ailerons last after you have
experience because they're a bit more
complicated.
HINGING ELEVATOR
AND RUDDER
Slip the control surface over the
hinges you've already glued in place
and align everything (see Fig. 6-20).
Fig. 6-22. Sop up extra glue with a dry tissue.
NA LS E A Ta
2A Dri alloron torque rod hole. В gs ns
— B. Then rockdrill along leading Tu: >
| edge center ing to elongate hı ole.
Move the control surface 45° in both di-
rections to check the hinge gap. You
want only enough gap to allow this
plus or minus 45° movement.
Hold the surface at the 45° position
and apply a drop of thin CA to the ex-
posed side of each hinge as shown in
Fig. 6-21. Remove the excess with a tis-
sue as shown in Fig. 6-22. Finally, turn
the work over, bend the control surface
45° the other way, and repeat the CA
application on the second side. That's
all there is to hinging the elevator and
rudder.
HINGING THE AILERON
The complication with ailerons is
that while you're hinging them, you
also have to epoxy the torque rods in
place. Before you do any gluing, en-
large the aileron torque rod holes as
shown in Fig. 6-23, then test fit the ai-
leron over its hinges and torque rod to
be sure everything slips easily into
place. Mix a batch of 30-minute epoxy.
Do only one aileron at a time, and
DON’T USE FASTER EPOXY!
Use a pin to drive epoxy into the
torque rod hole. You'll probably have to
do this two or three times to get all the
bubbles out and fill the hole com-
pletely. Once you've done that, slip the
aileron over the hinges and torque rod.
Use an alcohol-soaked tissue to clean
off excess epoxy.
Make sure you can move the aileron
45° in either direction, then glue the
hinges as you did with the elevator and
rudder. When you've done this, again
clean up any epoxy, then set the wing
aside while the epoxy cures completely.
Finally, check the control surface to be
sure you can still obtain 45° movement
either way. While you're at it, tug hard
on the control surface, just to be sure
you can’t pull anything loose.
PREPARING THE
WING SADDLE
Widening the saddle: Some planes’
wing saddles aren't wide enough to ac-
cept seating tape. If yours is narrower
than Y4", glue Y4"-square balsa to the
inside of the saddle on each side of the
fuselage (see Fig. 6-24).
Leveling the wing: Place the wing
on the saddle and hold it down with a
couple of rubber bands. Make sure it's
centered, then measure from each wing
tip to the workbench. If the measure-
ments differ by more than 44”, sand the
high side of the saddle and check again.
Be careful not to take off too much
wood on the first try. If the saddle is
way off, you may have to shim the low
side with 3%” balsa, then sand until the
wing is level.
Installing the wheels: This step is
often more of a nuisance than you'd ex-
pect because the wheels sometimes
don't fit over their axles. If you have
this problem, file any burrs off the ax-
les. After that the wheels probably will
go on but still won't turn freely, so the
next step is to drill out the hubs. If your
landing gear is %/2" wire, use a %/s” drill,
nota larger one, Ifit'sa 7” wire, asit is
on most smaller planes, use a Vs” drill.
You can work out your own tech-
nique for drilling the holes, but here’s
mine, which can be a little risky. I in-
sert the drill through the hub, then
while holding the wheel, I turn on the
drill and rock the wheel a couple of
39
Fig. 6-24. Widening the wing saddle to accept seating tape. You'll have to shape the
square balsa to make it fit on some airplanes.
times while I drill, then give the wheel
a quarter turn and drill and rock again.
I repeat this for a full revolution of the
wheel, then check to see if it fits. If it
doesn’t, I repeat the procedure until it
does.
Once the wheel fits the axle and
turns freely, take it off, install a wheel
collar on the inside of the axle, replace
the wheel, and install the outside
40
wheel collar. Tighten the collars as
much as you can with your hex wrench
(see Fig. 6-25). One of the most com-
mon flying mishaps is a wheel that
comes off in flight. Chances are your
plane will land without serious dam-
age, but if you can’t find the wheel and
its collar in 40 acres of woods or tall
grass, you can’t fly until you buy new
ones.
Fig. 6-25. Wherever possible put a wheel
collar on both sides of the wheel.
One minor problem: At least one of
the planes covered here has main gear
axles too short to accept the wheel and
two collars, so you'll have to make do
with one collar on each of these. How-
ever, even on that plane, you need two
collars on the nose gear.
That completes the post-covering as-
sembly. You can now begin to install
the radio system for keeps.
7. Final radio installation
The plane looks like a plane now and
the main thing keeping it from flying is
that radio still sitting on the bench. A
few hours of work will take care of that,
but don't rush it. ;
AILERON SERVO
INSTALLATION
Start by installing the aileron servo.
THE MANUAL shows you how everybody
else does it, but I'll describe a quicker
way that’s more secure and provides
better vibration protection.
Cut a hole in the bottom of the wing
just aft of the main spar as shown in
Fig. 7-1. Dont forget to leave Ye” of the
rib to support the top sheeting, or on
planes with no top sheeting, to support
the covering material.
The easiest way to cut out the center
rib is brutal. Figure 7-2 shows how.
You'll shortly have a. jagged hole.
Clean it up with your modeling knife,
and test fit the servo to be sure it
doesn’t touch wood at any point except
the bottom, where it will be cushioned
by foam rubber.
Fig. 7-1. The hole in the bottom of the wing
should be wide enough to clear the servo
by YA” on each side, long enough to allow
the servo lead at least %" clearance, and
deep enough that it leaves 14" of the cen-
ter rib under the top.
Now cut Y4"- or %"-square balsa rails
to support the bottom sheeting on three
sides as shown in Fig. 7-3. Glue the
rails to the sheeting and sand them
flat. Next, attach a square of Y4"-thick
foam rubber to the bottom of the servo
with silicone glue. Smear silicone glue
over the tops and insides of the rails,
but not on the end without a rail be-
cause that's where the servo lead exits.
If you glue the lead, it will be difficult
to remove the servo without damaging
it. Now smear silicone glue over three
sides of the servo case at the level
where it will meet the rails as shown in
Fig. 7-4. Also put a dab of glue on the
foam rubber underneath, then insert
the servo into the wing. Smooth out the
glue around the servo, then check to
see that the servo case doesn’t touch
the wing, and set the assembly aside to
cure (see Fig. 7-5). If you ever need to
remove the servo, cut it out with your
modeling knife.
IN-FUSELAGE SERVO AND
PUSHROD INSTALLATION
Fig. 7-2. Grab the rib with needlenose pli-
ers and twist it.
While the glue cures on the aileron
servo, you can work on the fuselage.
Re-install the three servos in the fuse-
lage, then slip the elevator and rudder
pushrods into position and install the
clevises on their threaded ends. Tempo-
rarily hook up the Rx, servos, switch
harness, and battery. Turn on the Rx
and Tx and center the rudder, elevator,
and aileron trim tabs. Set the throttle
stick and trim tab to the half-open
position.
If the elevator pushrod exits through
the open end of the fuselage, remove
the clevis, slip a clevis keeper over the
metal rod, then screw the clevis back in
place (see Figs. 7-6 and 7-7). If the
pushrod exits through a slot, omit this
step. If a keeper were to come loose and
lodge in a slot, it could interfere with
control movement.
- With the clevis in, fasten the eleva-
tor pushrod, rudder pushrod, steering
cable, and throttle cable to their servo
arms and put the rudder and elevator
arms on the servos in their neutral po-
sitions. Install the throttle arm on its
Fig. 7-3: The supporting rails should be
Ya"- or %s"-square balsa.
Fig. 7-4. Do not smear any silicone glue on the end of the servo
case where the lead is.
’
Fig. 7-5. The aileron servo in place.
41
Figs. 7-6 and 7-7. The clevis keeper is just
a slice of silicone fuel line that helps pre-
vent the clevis from popping open.
Fig. 7-8. A pin stuck in the trailing edge of
the control surface allows you to measure
control throw accurately.
Fig. 7-9. Cut cable braces from scrap ply-
wood or balsa.
servo in the position that's halfway.
Temporarily connect the rudder and
elevator clevises to their control horns
to see how close to neutral those sur-
faces are. Adjust the clevises until both
are exactly neutral.
Loosen the steering cable setscrew at
the servo and set the nosewheel to its
neutral position, then tighten the set-
screw. Adjust the throttle cable the
same as you did in the preliminary ra-
dio installation.
Consult the chapter on your kit for
the control throws recommended for
your airplane. Measure the throw first
on the rudder, then on the elevator (see
Fig. 7-8). Adjust by moving the clevis
42
Fig. 7-10. The completed installatia. should look something like this.
FIG. 7-11 THROTTLE ADJUSTMENTS AT THE SERVO END
A. Adjustment at the cable connector
Cable brace Elevator servo
L 1 à
fy
4
Loosen
this setscrew
to adjust
cable
1 x i
J 7 ] q
7 7
Throttle servo Rudder servo
With the servo pushing the cable as far forward as
possible (stick and trim tab in fully open position),
the carburetor barrel should be wide open and the
servo shouldn't be stalled. To achieve this condi-
tion, loosen the pushrod connector setscrew and
aliow the cable to seek its own position. Be sure
the carburetor barrel stays open while you do this.
Once you've got the right arrangement, re-tighten
the setscrew.
8. Ad:ustment of servo arm length
Cable brace Elevator servo
Lo : 1 à
=== -
L ld
7 7 3
Throttie servo Rudder servo
\ -Nith the throttie stick and trim tab in the fully
closed positions, the carburetor barre! should be
sompletely, but just barely, closed. If the barrel is
"ll open, you need to increase the length of the
at justable servo arm, then repeat the adjustment
a ‘the cable connector with the throttle stick and
kar tab fully open. Then close both stick and trim
(4) again to see if the carburetor barrel closes
эгорейу. If the barrel closes before you com-
pist:y close the stick and trim tab, you need to
s:ter'en the arm, readjust at the cable connector.
a uw! ty again. It takes some fiddling, but be sure to
gt! i right.
from one hole in the horn to another. In
general, it's best to be as far out as pos-
sible on both the servo arm and the
control horn. This minimizes slop, re-
ducing the likelihood of control surface
flutter. The elevator throw should be at
least the specified value.
If you have to be off a hair, be sure
you have slightly more throw than
called for. If you have too little throw,
you may not be able to flare the plane
for landing. Rudder throw isn’t as criti-
cal, but should be approximately the
amount specified.
If you're using an elevator clevis
keeper, now is the time to slip it over
the clevis. To provide yourself with a
little working room, give a full elevator
command to push the clevis out of the
fuselage, then turn off the Rx and slide
the keeper in place. Turn the Rx back
on to neutralize the control surface,
ther switch off both the Rx and Tx.
Th: next step is to install throttle
and steering cable braces. Usually I
just cut pieces of plywood or balsa scrap
as shov-n in Fig. 7-9 and epoxy them in
place n:ar the servo ends of the nylon
cable tuings. Be careful not to get ep-
oxy o:, the servos, servo leads, servo
tray, ox |" x (see Fig. 7-10).
Most 0° the time one brace per cable
is enou zh, but test the control after the
epoxy cayv::. If the cable bends a lot un-
der presgut 2, glue a second brace to it
just before .t disappears into the fuel
tank compartment.
With the cables braced, you can
make fina.g« justments to the steering
and throttig controls. This is easy for
the steering: ble. Loosen the setscrew
on the stee-i1g servo arm (rudder
servo). Turn cn the Rx and Tx and
make sure t.- the rudder trim tab is
= =
e Ema
BE 1
TEO
Fig. 7-15. Switch and charge jack as
viewed from the outside.
Fig. 7-16. Glue balsa braces over the re-
ceiver and battery to prevent moving.
Fig. 7-13. Tape the switch plate to the side
- of the fuselage, drifl two %«" screw holes,
— install the screws, then mark the switch
cutout with your modeling knife.
Fig. 7-14. The installation of the switch
should be made from the inside.
FIG. 7-17 ROUTING THE ANTENNA
B. Larger planes (.40 or larger engine)
with spacious radio compartments.
A. Small planes (.20-.25 engine) with
cramped radio compartments.
Rear wing hold-down dowel
Silicone tuel line guide tubes.
Glue these to the fuselage with
silicone rubber glue before
running antenna.
* ‘Antenna exits through silicone
“fuel line. Tape antenna to the
‚top of the fin.
Battery Receiver Th rottle servo Elevator servo M ; Battery Receiver Throttle servo Elevator servo
[ | | 1 1 L
| Y | ] /
ГО | |
. O | |
‘ani | 1 9 |
|
a e Rudder |
servo
|
\ Antenna |
wo er — I 1 ]
| q ] Г \ ] AS
Fuel tank Fuel tank e!
Antenna
compartment Lo compartment Tape end of antenna
E | to top of fin
running antenna.
Silicone fuel line guide tubes.
Glue these to the fuselage side
with silicone rubber glue before
Silicone fuel line inside exit
hoie to insulate antenna. Place
the exit hole iow in the fuselage
side so the antenna wil not come
close to the hold-down dowels. You
don’t want to accidentally rip it
out when installing rubber bands
on the dowel.
centered. Adjust the nosewheel so it
points straight ahead, then tighten the
setscrew. With the radio still on, set
the plane down on a flat surface (I use a
road in front of my house) and give it a
shove. If it turns right or left, make the
necessary adjustment at the servo ca-
ble connector and try again. When
you've got it right, tighten the setscrew
firmly, take the plane inside, and start
on the throttle adjustment.
Loosen the setscrew on the pushrod
connector on the adjustable arm, then
manually pull the throttle arm on the
carburetor to the fully open position.
The cable should slide through the con-
nector without resistance. Now move
both the throttle stick and trim tab to
the fully open positions and tighten the
setscrew. Gently move the throttle
stick toward the closed position, back-
ing off if you encounter resistance. If
you do, shorten the adjustable arm and
start over. If you don’t get any resist-
ance, close the stick all the way, then
close the trim all the way. If the barrel
is still open, lengthen the adjustable
arm slightly and try again. Keep fid-
dling until the barrel is slightly open
with the trim tab open and the stick
closed and the barre] is completely, but
Just barely, closed when you close both
stick and trim tab. Then check to be
sure that when you open the stick and
trim tab all the way the barrel is wide
open. Make sure the setscrew is tight-
43
ened firmly, then turn off the Rx and
Tx (see Fig. 7-11).
SWITCH AND CHARGE JACK
INSTALLATION
The switch and charge jack (see Fig.
7-12) go on the side of the fuselage op-
posite the muffler where exhaust oil
won't get on them. Put them out of the
way of the servo arms and cable braces
and where they won't interfere with in-
stalling the Rx and battery.
Having chosen the location, mark
the outline of the charge jack on the
outside of the fuselage. If your system
uses Futaba connectors, orient the jack
so the side with the raised line faces
the rear of the plane. This will make it
easier to fit the charge plug into the
jack. Now cut the hole for the jack,
making it a tad too small. You'll en-
large it later.
Tape the switch's on/off plate to the
outside of the fuselage and use it as a
guide to drill two holes. Slip the hold-
down screws through the plate and
holes and mark the cutout for the
switch itself on the covering with the
point of your modeling knife (see Fig.
7.13). Remove the switch plate and cut
out the switch hole, making it slightly
oversize in every direction. If the switch
is not free to move to its limits, engine
vibration could shut it off in flight! Test
fit the switch from the inside of the fu-
selage, and if all is well, replace the
plate and screw the switch in place (see
Fig. 7-14). Tighten the screws firmly,
but not enough to crush the wood.
Cautiously enlarge the hole you made
for the charge jack until you can just in-
- sert the jack. It should protrude Ys" to Ya"
outside the fuselage. Glue the jack in
“place from the inside with slow CA and
‘accelerator. Then glue the outside,
making sure you don’t get glue into the
jack. If you do, you'll have to replace
the switch harness (see Fig. 7-15).
BATTERY AND RX
INSTALLATION
With the switch harness in, you can
permanently install the battery and
Rx. Place them so you can get at the Rx
because you'll need to check the servo
leads before each flying session.
On the planes built for this book 1
glued the Rx and battery in place with
silicone glue, then braced them with
pieces of Y4" balsa as shown in Fig. 7-16.
After the last plane was done, a club
member showed me what looks like a
better way. Glue Velero, business-side
down, to the fuselage floor where you
want the Rx or battery to be. Place the
Rx or battery over the Velcro, then se-
cure it with a second strip of Velcro.
This installation is lighter and allows
you to remove components on a whim. Î
haven't tried it vet, but it worked well
in his plane.
44
Fig. 7-19. Slip the aileron servo arms over the Z-bends of both pushrods.
er E ve .
FE.
я
NT pad
LE
aa NE:
Е q
> В
E" +
Fig. 7-20. Attach the arm to its servo, adjust the clevises, then slip the clevis keepers
into their positions.
ANTENNA INSTALLATION
You'll want the antenna to exit with-
out touching anything solid, so dont
jam it against the battery or a piece of
wood.
Now you have to decide how to run
the antenna out of the plane. Figure 7-
17 shows a couple of options. On small-
er planes I usually run it out the left
side (away from the exhaust) well be-
low the rear wing hold-down dowel,
and attach it to the top of the fin. On
larger planes, I run it out the top of the
fuselage just behind the wing saddle.
The antenna must follow as straight
a course as possible and be guided
through pieces of fuel tubing glued to
the side with silicone rubber glue.
Choose your path to keep the antenna
LEFT AILERON
(Rear view)
Г-З
OLS
7
Left aileron is up; right aileron is down
O&A
FIG. 7-21 TRANSMITTER COMMANDS AND AILERON RESPONSES
This is the most important hookup on the airplane. Get it reversed and anybody can take it off, but nobody
can fly it. Planes with reversed aileron throw never fly for more than a couple of seconds.
RIGHT AILERON
{Rear view)
Right aileron is up; left aileron is down
as far as possible from other electronic
components.
Although there are several common
ways to attach the antenna to the fin,
all put the tension of a rubber band on
the antenna, which could conceivably
pull something loose. To minimize that
possibility, I just use a piece of cello-
phane tape to attach the antenna to the
fin, making sure not to quite pull it
tight when I stick it down. No matter
how you attach the antenna, there’ll be
a bit of “excess” hanging down. LET IT
DANGLE. If you cut it, you’ll detune
the receiver!
INSTALLING THE AILERON
PUSHRODS
Tape the ailerons in their neutral po-
sitions, then connect the aileron servo
lead to the Rx and turn on the Rx and
Tx. Center the aileron trim tab and
check to see that the servo arms are po-
sitioned as shown in the plans or THE
MANUAL.
Install a clevis on a threaded pushrod
and connect it to the torque rod horn.
Run the rod over the spot where it will
attach to the servo arm and mark it at
the servo arm hole with a fine-tip felt
pen (see Fig. 7-18). Make a Z-bend at
the mark. (See Fig. 4-57.) Duplicate
this procedure for the other aileron
pushrod, then remove the tape from the
ailerons.
Remove the servo arm, ream it out to
accept the rods, slip pushrod keepers
over both pushrods (see Fig. 7-19), in-
stall the rods in the arm, and replace
the arm on the servo (see Fig. 7-20). If
the ailerons are not in their neutral po-
sitions, adjust them at the clevises.
Position the wing on its saddle and
move the aileron stick on the Tx to the
right. The right aileron should rise and
the left one should go down. If it works
the other way, flip the servo reverser
switch and try again (see Fig. 7-21).
Now check the chapter on your plane
for the correct aileron throws and move
the torque rod horns up or down to get
the throw you need. If necessary, read-
just the ailerons to their neutral posi-
tions with the clevises.
The radio installation is now com-
plete and only a few important odds
and ends remain before flight.
45
8. Final touches
With the radio installed, there are
just a few operations to take care of be-
fore heading to the flying field.
WING SEATING TAPE
Cut two pieces of seating tape to fit
the wing saddle and set them aside. I
drill a series of 7” holes in the balsa
part of the saddle (see Fig. 8-1). If your
plane has see-through windows, make
sure you do not inadvertently drill
them. Apply a film of silicone glue over
the entire saddle and use a pin to work
glue into the holes (see Fig. 8-2). Re-
move the backing from one piece of
seating tape and place it sticky side
down on the saddle. Smooth it out and,
if necessary, pin it in place. Repeat the
procedure for the second piece of tape,
and let the glue cure for a few hours. If
your tape has two sticky sides, leave
the protective covering on the second
one for now. When you're about done
working for the night, remove the cov-
ering to expose the second sticky side.
Smear a thin layer of silicone glue over
the tape and let it cure overnight. Next
work session you can trim excess glue
or tape with a razor blade.
COWL INSTALLATION
If your plane has a plastic cowl
Fig. 8-2. Put silicone glue over the saddle and drive it into the holes with a pin. Then
and/or fuel tank cover, install them
now according to instructions in the
chapter on your plane and in THE
MANUAL. |
MUFFLER INSTALLATION
If you just bolt the muffler in place, it
will leak grease all over the engine
compartment, so seal it with silicone
rubber glue as shown in Figs. 8-3, 8-4,
and 8-5. I used red glue because it's
more photogenic, but most people use
clear. When you've finished installing
the muffler, connect the vent line from
the fuel tank to the pressure fitting.
INSTALLING THE PROP
AND SPINNER
If you're using a glass-filled nylon
prop, sand off the sharp flashing before
attempting to install it. Otherwise you
could get a bad cut when you grip the
prop to tighten the nut. You should
also paint the tips white or yellow so
you can see them when the engine’s
running. Many people have taken that
ride to the hospital emergency room af-
ter putting their hand where they
didn’t see a prop.
The spinner backplate goes on the
prop shaft first, followed by the prop,
the washer, the nut, and the spinner.
smooth the glue layer with your finger before laying the seating tape over it.
46
You may have to ream out the spinner
backplate to get it on. I use needlenose
pliers for this job (see Fig. 8-6). You
also may have to ream out the prop (a
Fox reamer is handy for this), and with
some spinner/prop combinations you'll
have to trim the spinner to clear the
prop. Use your modeling knife and a
measure of caution. (I've been known to
stab myself.) Try to do all your trim-
ming on the side opposite the pegs that
snap the spinner in place.
If you ever intend to start the engine
by hand (and by that I mean with a
chicken stick, not a finger) you'll want
Fig. 8-3. Make a gasket by spreading sili-
cone glue over the mating surfaces on the
exhaust and mutfier. Be careful that glue
does not get into the engine and do not
use $0 much that it squeezes in when you
tighten the muffler.
Fig. 8-4. Clean off excess glue from the
mating surfaces.
Fig. 8-5. Attach the tank's vent line to the
muffler pressure tap. |
to tighten the prop so that it is parallel
to the ground at the beginning of the
compression stroke. This gives you the
best angle for flipping. If you plan to
use an electric starter exclusively (not
a bad idea) don’t worry about prop posi-
tion. Just snap the spinner in place and
go on to the next task.
BALANCING THE PLANE
Find the recommended balance point
in the chapter on your airplane and
mark it in ballpoint pen on the under-
side of both wings.
Note: This is not necessarily the bal-
ance point given in THE MANUAL, but it
is the one I've had the best luck with in
test flights of the model. If you use a
more forward balance point, you'll need
more elevator throw and the plane
won't fly as well. If you use a more
rearward balance point you may need a
bigger insurance policy. Tail-heavy
planes can be unflyable, but they get
into the air before you find that out.
Place your fingers on the balance
lines you drew and hold the plane. If it
sits level, it’s already balanced. If the
nose drops below the horizon, add
weight to the tail. If the tail drops, add
weight to the nose as far forward as you
can get it. Don’t fly before you get the
balance right.
Anything dense that you can glue to
the plane will serve as a balance
weight. I've been known to epoxy quar-
ters to the tail. Expensive? Not really.
When the plane crashes or wears out, I
spend the quarters. Most people use the
stick-on weights .available at hobby
shops. When I use these, I slice off the
sticky tape and epoxy the weights to
the plane. Maybe I'm a worry wart. I've
never seen a stick-on weight come off,
but they make me nervous. If you ep-
oxy a weight in place, cut away the cov-
ering where you intend to place it so
the epoxy will have some wood to stick
to, then dip the weight in epoxy to en-
capsulate it in the stuff before position-
ing it on the plane.
WING WARPS
If your plane is intended to have
washout, skip this section and refer to
THE MANUAL on how to do the washing.
If you're building an ARF with a sym-
metrical airfoil, you can also skip this
section. It's difficult to check symmetri-
cal wings for warps, and ARFs are no-
toriously free of them. But if the wing
is flat, check it out. A warped wing
won't handle well in the air. A badly
warped one won't even stay in the air.
If you have a flat bottom wing with-
out washout, lay one panel on the
building surface. It should lie flush at
all points. If it's off by more than Ya"
Fig. 8-6. Reaming the spinner backplate.
Be careful not to overdo it.
Fig. 8-8. Now that you are finished build-
ing the plane, this book can assist you in
learning how to fly it.
anywhere, you have to straighten it. To
do this, twist the wing panel opposite
the warp (it helps to have an assistant)
and use your trim iron to heat the cov-
ering on both sides as you hold the
twist. Remove the heat and hold the
twist until the covering cools, then
check to see if you've gotten rid of the
warp. If not, repeat the heating and
twisting until you have.
WING CENTER MARKINGS
On most trainers it's possible to place
the wing a bit off-center and mess up
the flight characteristics. To prevent
this, all you have to do is iron align-
ment marks to the center of the wing's
leading and trailing edges (measure;
don't eyeball the centers) and to the
center of the fuselage just ahead of and
(LEARNING TO FLY)
RADIO CONTROL
MODEL AIRPLANES
BY JOHN CARROLL
just behind the wing (see Fig. 8-7).
Congratulations! You've finished the
plane. However, the engine needs a lit-
tle tweaking and the prospective pilot
needs a thorough understanding of
What is required to fly these models.
Most hobby shops stock LEARNING
TO FLY RADIO CONTROL MODEL
AIRPLANES (see Fig. 8-8), the book
which covers those subjects in detail.
Im biased, having written that book,
but tens of thousands of new RC pilots
have cut their teeth on it and it seems
to have helped.
Don’t try to fly the plane on your
own. You've put too much work into
the plane to bust it up the first time
out. Get help from a competent instruc-
tor for the first flight, and your plane
should give you hours of enjoyment.
Fig. 8-7. Anexpert at the field shows how to balance a plane — just for show in this case
because ttis Eagle has nearly 400 flights on it. When you balance your plane, do it in-
doors whee wind won't interfere.
47
le и Ce CREE JANE os EM
E. FRE pan ML A ;
i a E“ UD eE SEL
“ra LE a A ka > À 1 ‘re ВЫ Ш A Y 2 A,
LTS ZONE A
' re Po PA x . Me Ры
A % О LA
LA
,; ВЕ . Lo Ш
ВЫ EE | “1 CF. . a +
BF vr а РОС Ш re Ко A ES N
> had ai en y St ae ie e. Дачи
4, riba
“- >
ra ела =
more rare
rE EE sana В pre .
Ea ptet La
hela
КЕ La per “ye
2 и od en Xen
MON PF fy hg,
en FOP +
В ; a. ES
aL ñ A
e
ca Sil debo А: ся, EA
A « TT a EA) E
gd N tt r'
A
NN e NU N ue Lu
PA IY The RELI ” у
^
г
=
PES
FIG. 9-1
LUBRICATING TORQUE RODS
A. Torque rod with tubes
Torque rod tube Torque rod
Globs of petroleum jelly applied
only at these points, but grease
torque rods wherever they may
encounter glue.
AIN
O
O,
B. Torque rods with tabs
Torque rod tab. Don't get petroleum
jelly on this area.
9. Building the Goldberg Eagle
2, Eagle 63, and Eaglet 50
— The remaining chapters provide spe-
cific instructions for building ten RC
planes. The ones included are some of
the best, and they're ideal for someone
building his first RC plane. This chap-
ter covers the Goldberg Eagle planes.
FRAMING THE MODEL
With the following exceptions, build
the framework for the Goldberg Eagle
planes as instructed in THE MANUAL.
The Wing and Tail
1) Be sure to sand all burrs from die-
cut parts before gluing them. This
gives you a better fit, which means a
lighter, straighter, stronger model.
2) Wherever THE MANUAL says to
mark or cut hinge slots, ignore it.
You'll be using CA hinges, rather than
kit hinges, and will do all marking and
cutting after the model is covered, not
now.
3) Dihedral joiners: Use epoxy rather
than CA glue to attach dihedral joiners
to the spars, and use C-clamps, rather
than the plywood joiner clamps sup-
plied with the kit, to hold these parts
together while the glue dries. A sheet
of waxed paper between clamp and
wood will help you avoid gluing the di-
hedral joiners to the clamp.
4) Torque rods: The torque rods are
those funny-shaped pieces of wire that
connect the ailerons to the aileron
pushrods. On the Eagle 2 they are held
to the wing by a nylon tab. On the
other Eagle planes they are held in
48
place by a plastic tua. If you get glue |
between the torque :2d and whatever
holds it to the wing, the ailerons will
never work smoothly. iTo avoid this
possibility, smear a little petroleum
jelly at the junctures ¢f rod and tab (or
rod and tube) before gung anything in
place (see Fig. 9-1). Ze careful not to
use more lubricant thin necessary be-
cause it will prevent getting a good
glue joint. THE MANUAL says to glue
these parts with CA, ';1t I suggest you
use epoxy because C*1 glue can cut
through the petroleurr jelly and gum
things up.
5) Connecting вого: + rods to aile-
rons: At some point yo..11 have to drill
a hole in each ailero:: to accept the
torque rod. First drill :a hole as THE
MANUAL says to, then: tk the drill to
elongate the hole as sho xn in Fig. 6-23,
page 39. When you insta | the aileron,
you'll fill this long ‘ho.# with epoxy,
providing a large bearing surface that
will reduce the likelihocà of vibration
working the rod loose: *
6) Aileron clearance: “HE MANUAL
suggests that you leave enough clear-
ance at each end of the ail ion to pass a
matchbook cover. These nips have a
way of disappearing, 80 Lanve a little
extra — about Ув.
7) Mounting the aileron servo: Ig-
nore THE MANUAL's instrustions and
don't cut holes or mount the servo until
after the wing is covered. Then see
Chapter Seven (Final Radic Installa-
tion) for the procedure. :
Fig. 9-2. Notice the gap between the fuse-
lage bottom and the fire wall. You'll have
to seal it with epoxy to prevent oil from
getting into the fuselage.
The Fuselage
1) Deburring: Before beginning as-
sembly, lightly sand all die-cut parts to
remove burrs. If you don’t, you can get
weak joints and a crooked airplane that
flies crooked. Don’t glue anything until
it fits perfectly.
2) Warped fuselage sides: In most
Eagle and Eaglet kits I've seen, the
light ply fuselage sides have been
SPECIFICATIONS FOR THE GOLDBERG “
EAGLE 2 AND EAGLE 63
Test Plane Specifications
Wingspan: 63" : oo tes пес Зо. :
Wing area: 715 square inches | e a 8
Weight:
Eagle 2: 84 ounces (5 pounds, 4 ounces)
Eagle 63: 87 ounces (5 pounds, 7 ounces)
Wing loading:
Eagle 2: 16.9 ounces per square foot
Eagle 63: 17.5 ounces per square foot
Engine:
Eagle 2: Royal .40 two-stroke
Eagle 63: Royal .40 two-stroke
Radio:
Eagle 2: Futaba Conquest e-channel (4 used)
Eagle 63: Futaba Conquest 4-channel
Propeller:
Eagle 2: 10/6 Master Alrscrew
Eagle 63: 10/6 Zinger o = 2
Setup Recommendations
Controls: 4 channels — elevator, rudder, throttle, and alle-
rons. DO NOT OMIT AILERONS. |
Dihedral angle: Build the “aerobatic” wing (the one With’
the least dihedral). This wing will fly more cleanly than the _—,
others, and because you'll have aileron control, you won't ;
need a lot of dihedral to turn the airplane.
Balance point: Balance as shown on the plans.
On-board electronics and pushrod arrangements: See -
THE MANUAL and the plans. — A
Elevator and rudder pushrod type: Wood |
Control throws: Set these up as recommended in THE MAN- a
UAL. The ailerons will probably be touchy at first. If so, re-
duce throw a little at a time with the advice and assistance _
of your instructor. If your Tx has rate switches and you fy У
on low rate, you can dial in throw changes as needed.
General Hardware and Materials Sizes
Fuel tank: 8 to 10 ounces
Wheel collars: %." o
Engine: .40 two-stroke .
Propeller: 10/6
Spinner: 2%"
Wheels:
Main Wheels: зу"
Nosewheel: 2%"
Fire Wail Hardware
Quantity Нет
8 4-40 machine screws s with washers
8 4-40 blind nuts
4 6-32 machine screws with washers
4 6-32 blind nuts
(Note: Many of these items are supplied In your kit. Count
what you find and buy only what isn't provided.)
a A Epoxy these pieces
> al in place
Fig. 9-3. Use epoxy to glue the windshield top former in place.
— Wing loading: 19.2 ounces per square foot
— Controls: 4 channels — elevator, rudder, th
diria 7
i Others, and because you have aileron contro
- need à iot of dihedral to turn the airplane. 4
Le й Ve TASTE
— the throw a little at a time with the advice and help ot.yoú
SPECIFICATIONS FOR THE GOLDBERG
EAGLET 50 ое
Test Plane Specifications ре
Wingspan: 50 E.
Wing area: 450 square inches | a
Weight: 60 ounces (3 pounds, 12 Co Ee
ounces) |
Radio: Futaba Conquest 4-channel
Engine: Fox .19 BBRC, 2-stroke
Propeller: 9/5 Top Flite
Setup Recommendations ;.
rons. DO NOT OMIT AILERONS. TA
Dihedral angle: Build the “aerobatic” wing (t
the least dihedral). This wing will fly more cleanly.
Balance point: Balance as shown on the pi
On-board electronics and pushrod
arrangements: See THE MANUAL, and the р! ns:
Elevator and rudder pushrod type: Wood ~~
Control throws: Set these up as recommended in THE M;
UAL. Ailerons will probably be touchy at first. if so, redt
instructor. If your Tx has rate switches and you: Лу от y
rate, you can dial in throw changes as needed. 2 эй
- General Hardware and Materials 8 ps
Fuel tank: 4 ounces |
Wheel collars: A”
Engine: .19 to .25. Don't use an engine smaller than
bic inch. a
Propeller: 9.5 or 9.6 CAE Le
. Spinner: 2” | uE
Wheels: LEE
Main Wheels: 2%" TRE
Nosewheel: 2%" A
Fire Wail Hardware . a
Quantity item | В
12 - 4-40 machine screws with washers 1e
12 4-40 blind nuts a
(Note: Many of these items are supplied in your kit County;
what you find there and purchase only what isn't provided.) ; *
uk
. ad
FIG. 9-4 CARVING THE REAR HOLD-DOWN DOWEL
Fuel tank compartment Radio compartment
—; — ‚
/ ’
X d N oN
| |
Carve away the front half To tail — >
of the rear dowel to allow —b
|
}
the aileron torque rods
— |
—] '
full movement.
RL
49
warped. A slight warp is okay, but if
you hold the tail on the workbench and
the nose rises more than three inches,
you'll need to flatten it out. To do this,
throw the warped side into the bathtub
and cover it with hot water. After it has
soaked an hour or so, place it on your
building surface and weight it down
flat. I use bricks for this job, but any-
thing that won't dent or color the wocd
is okay. Allow the side to dry at least
overnight. When it's bone dry, check to
see if it's still warped. If it is, you'll
have to resoak it, prop it up in the cen-
ter, and weight the two high ends.
Keep at it until you've reduced the
warp to an acceptable amount.
3) Fire wall preparation: Don't drill
holes for the throttle and steering
pushrods until you begin preliminary
radio installation (Chapter Four in THE
BOOK). The model will be completely
framed by then.
4) Fire wall/fuselage gap: After you've
glued the fuselage together, check to see
if there is a gap between the fire wall
and the bottom sheeting (see Fig. 9-2).
If there is, fill it with epoxy to prevent
oil from leaking in when you run the
engine.
5) Dashboard (Eaglet only): Before
installing the dashboard in the Eaglet
50, cut it along the curved mark. This
will give you needed room for the fuel
tank.
6) Trimming the forward cabin for-
mer: If you use even a moderately large
tank, you'll have to trim this former so
it not only clears the tank, but leaves
room for the foam rubber padding that
protects the tank.
7) Gluing the windshield top former:
Glue this part in place with epoxy (see
Fig. 9-3). It's hard to make a secure
joint with CA.
8) Rear hold-down dowel: Cut away
half the thickness of the rear hold-
50
FIG. 9-5 SLIDE CHECK BLOCKS
A. Cutaway Side view
is in place.
8, View from beneath wing
Slide check blocks made from scrap el
plywood (not balsa) are glued to the
underside of the wing and butt against
the rear cabin former when the wing
TT
~~ Rear cabin
former
Slide check blocks В
down dowel inside the fuselage as
shown in Fig. 9-4. This will give the ai-
leron torque rods room for complete
movement.
9) Servo rail installation: Complete
this operation according to THE MAN.
UAL's instructions, but brace the rails
as shown in Fig. 4-13 (page 17). Then
turn to Chapter Four in THE BOOK and
begin preliminary radio installation.
POST FRAMING ASSEMBLY
1) Slide check blocks: The wing on
this airplane tends to slide to the rear,
so the original design called for slide
check blocks. If you're building an Ea-
gle 63 or Eaglet 50, the plans should
show you where to put them. I couldn't
find them on the plans for my Eagle 2,
but they should be installed anyway.
Figure 9-5 shows how to make and in-
stall them. Don't do this until after cov-
ering the wing.
2) Post-covering assembly: Turn to
Chapter Six for such operations as
hinging control surfaces, installing the
horizontal stabilizer, and so on.
3) Final radio installation: Ignore
THE MANUAL on this subject except to
get the proper size and shape for the
pushrods and the positions of the servo
rails and tray. Turn to Chapter Seven
for all other final radio installation
procedures.
4) Final touches: Once you've fin-
ished the radio installation, turn to
Chapter Eight for final adjustments,
balance, and assorted odds and ends.
REE OT
E a
+. os es = vs » o 2 ” am. + E
. + e? RE LE . .
“e ry ‚ . + , ; ‚mw. 5 Rad . = A CLL
"e v . ER NS E @
и iv . ce , e +. > né : € |
= Se
E Эа Te x
un a. . ok Er: Ma
/ Fo хм Taig To hs,
ei
hed
+
— 10. Building the Great Planes
; PT-20 and PT-40
This plane requires Gold-N-Rods
With the following exceptions, frame
the Great Planes PT-20 and 40 accord-
ing to the instructions in THE MANUAL.
One caution: If you're installing a
K & B engine with a radial mount, fol-
low the installation instructions in THE
MANUAL. However, install throttle and
nose gear cables as instructed in Chap-
ter Four of THE BOOK. Don’t use the
solid pushrod wires that come with the
it.
HINGE INSTALLATION
No matter what THE MANUAL says,
don’t cut hinge slots or install hinges
until after the model has been covered.
Then follow the instructions in Chap-
ter Six of THE BOOK. Throw out the
hinge material that comes with the kit
and use CA hinges.
FUSELAGE CONSTRUCTION
1) Before gluing anything, use your
razor saw to cut the Y" lower triplers
(called doublers in some MANUALS)
down to Ye”; this will give you needed
room for engine and nose gear installa-
tion. Later, you'll add braces to more
than compensate for any forfeiture of
strength caused by thinning the triplers.
2) Because of the tail design in this
airplane, it is difficult to install wooden
pushrods so they can’t hang up (see
Fig. 10-1). Use Sullivan Gold-N-Rods
instead of the wood pushrods shown in
THE MANUAL. Because you'll use a dif-
ferent pushrod system, you'll need to
cut the pushrod openings not as shown
in THE MANUAL, but as shown in Fig.
10-2. Don't cut any openings until you
get to Chapter Four (Preliminary Ra-
dio Installation).
3) Before you begin rubber banding
the fuselage sides over formers, sand
off any burrs on the wood that could in-
terfere with a perfect fit.
4) Don't plank the top of the fuselage
until after you've completed prelimi-
nary radio installation (Chapter Four).
5) Don't drill the holes for the throt-
tle or steering “pushrods” until you
commence preliminary radio installa-
Fig. 10-1. This tight fit is why | recommend substituting Gold-N-Rods. Wood pushrods
could easily hang up if you didn’t install them perfectly.
51
FIG. 10-2 LOCATIONS OF GOLD-N-ROD EXIT HOLES
A. PT-20 В, РТ-40
Elevator (right side) Elongate hole to accommodate outer rod.
LD
Elevator (right side) Elongate hole to accommodate outer rod.
7
| DP
Y” To front of plane ——=
Y
To front of plane ———-
ги
Elongate hole to accommodate
outer rod.
——#——— To front of plane
Rudder (left side)
Elongate hole to accommodate
outer rod.
«—— ——— To front of plane у"
Rudder (left side)
UT
М 4%" -
- - 2. A . E. | o
ия = В © Ч 3 bi Fu FE
EC | 9. Mu | of
A -—
- у
Fig. 10-3. Add braces under the engine
bearers. Note that there are only three
braces. The fourth, if installed, would in-
terfere with the steering arm.
tion. Then follow the instructions in
THE BOOK.
6) THE MANUAL says to screw the
breakaway plates in place, but for secu-
rity you should bolt them with 4-40
machine screws and blind nuts.
7) Because you cut the triplers down,
it’s a good idea to install braces under
the engine bearers, as shown in Fig.
10-3.
8) Don’t mount the stab and fin on
the fuselage until after the plane has
been covered. See Chapter Six (Post-
Covering Assembly) for details.
FRAMING THE WING
1) Setting the dihedral: Build the ai-
leron wing (the one with less dihedral).
Take pains to fit the spars together per-
52
Fig. 10-4. After covering the wing, glue the wing plates in place. Strip away the wing cov.
ering to provide a solid wood-to-wood joint.
fectly. This is more important on PT
models than on most planes because
the PT planes have no balsa sheeting
on top of the wing.
2) Joining the wing panels: Use
thirty-minute epoxy for this job. Don’t
even consider using faster epoxy!
3) Aileron torque rods:
a. When you cut the groove for the
torque rod bearing, be sure to make it
deep enough to accept the whole bear-
ing. Otherwise the trailing edge piece
won't fit, which means the wing won't
quite fit the saddle and the plane won't
fly right.
b. Use epoxy glue, not CA, to install
the torque rods. CA can easily get into
the bearings and restrict movement.
Epoxy is less of a problem, but to be
sure, use petroleum jelly to keep glue
out of the bearings (see Fig. 9-1, page
48).
c. Drill torque rod holes in the aile-
rons, then elongate them by rocking
the drill. See Chapter Six for details.
d. Wing plates: Don’t install these
until after they and the wing have been
covered (see Fig. 10-4).
e. Wing hold-down dowels: Replace
the He" dowels in your kit with longer
ones. Dowels should protrude 7%" to 1”
from each side of the fuselage.
f. Test fitting the wing: Make four
sets of knotted rubber bands and use
two on each side to test fit the wing (see
Fig. 10-5). These will provide enough
tension to hold the wing in place but
not enough to damage the trailing
edge. You'll strap the wing tighter
when flying, but by then you’ll have in-
- stalled the wing plates.
NEEDLE VALVE CUTOUT
~ IN FUSELAGE
Cut out enough of the fuselage front
to allow easy access to the needle valve
SPECIFICATIONS FOR THE PT-20
Test Plane Specifications
Wingspan: 52%"
E Wing area: Approximately 525 square inches
; Weight: 62 ounces (3 pounds, 14 ounces)
= Wing loading: Approximately 17 ounces per square toot
E. Radio: Futaba Conquest 4-channel
lent engine, but too small for this plane. Use a.19to 25. )
Propeller: 8/4 Top Flite -
Setup Recommendations
| 4 Controls: 4 channels — elevator, rudder, throttle, and alle-
F : rons. DO NOT OMIT AILERONS. ©
Г - Dihedral angle: THE MANUAL gives you two dihedral op-
E. tions. Build the wing with the lesser dihedral.
: Balance point: Balance as shown on the plans. Also see
| - THE MANUAL for lateral balancing.
… On-board electronics and pushrod arrangements: See the
£. accompanying drawing.
.- Elevator and rudder pushrod type: Goid-N-Rods
© Control throws: Set these up as recommended in THE MAN-
© UAL. Allerons will probably be touchy at first. If so, decrease
.. alleron throw a little at a time with the assistance of your in-
> - structor. If your Tx has rate switches, you can dial in these
-- changes as needed,
General Hardware and Materials Sizes
- Fuel tank: 4 ounces
; Wheel collars: %:" |
- Engine: .19 to .25 two-stroke
— Propeller: 9/5 to 9/6
Spinner: 2”
Wheels:
Main Wheels: оу"
Nosewheel: 27”
1 3
5
=
i
e
i
Fo
i
Es.
7
Fire Wall Hardware
Quantity Item
12 4-40 machine screws with washers
12 . 4-40 blind nuts
. - | -Pushrods В
:- Quantity Item JRE
a 4 Metal with 2-56 thread at one end
«- 1set Gold-N-Rods, semi-flexible
- (Note: Many of these items come > with your kit. Buy only
- what isn't provided. » |
Radio component arrangement recommended for Royal 40T, Royal
20T, and Great Planes PT-40.
Throttle cable Receiver Throttle Elevator
Fuel tank Battery Steering cable Rudder
compartment
NOTE: While all four planes can use this arrangement, the Roya-Air
20T and 40T use wooden pushrods while the Great planes PT-20 and
PT-40 should be built with Gold-N-Rods.
Engine: Fox .15 BBRC two-stroke (Note: This is an excel- -
' what isn’t provided).
SPECIFICATIONS FOR THE PT-40_..
Test Plane Specifications
Wingspan: 60”
Wing area: 675 square inches
Welght: 87 ounces (5 pounds, 7 ounces)
Wing loading: 18.6 ounces per square foot
Radio: ACE Silver Seven
Engine: Royal .40 two-stroke
Propeller: 10/6 Top Flite
Setup Recommendations
Controls: 4 channels — elevator, rudder, throttle, and aller;
rons. DO NOT OMIT AILERONS. Жо
Dihedral angle: THE MANUAL gives you two dihedral opa
tions. Build the wing with the least dihedral. AA
Balance point: Balance as shown on the plans. Also see. -
THE MANUAL for lateral balancing. О
On-board electronics and pushrod arrangements: See the &
accompanying drawing. EE +
Elevator and rudder pushrod type: Gold-N-Rods es
Control throws: Set these up as recommended in THE MAN- ;
UAL. Ailerons will probably be touchy at first. If so, reduce
throw a little at a time with the advice and assistance of
your instructor. If your Tx has rate switches and you fly on -
low rate, you can dial in control throw changes as needed. 4
General Hardware and Materials Sizes ВЕ “= ©
Fuel tank: 8 to 10 ounces E
Wheel collars: %:” oo
Engine: .40 two-stroke
Propeller: 10/6 A
Spinner: 27” | ES
Wheels: AE.
Main Wheels: 3" bo,
- Nosewheel: 2%" e ES
| Fire Wall Hardware en a
Quantity item Ds
4-40 machine screws with washers
4-40 blind nuts
6-32 machine screws with washers TE
6-32 blind nuts
~ Pushrods
+ > © ©
Quantity — ltem 3
4 | Meta! with 2.56 thread at one en ,
1 set Gold-N-Rods, semi-flexible
(Note: Many of these items come with your kit. Buy® An
Radio component arrangement recommended for Royai 40T, Royal I...
20T, and Great Planes PT-40.
Throttie cable Receiver Throttle Elevator
Steering cable Rudder
Fuel tank Battery
compartment
NOTE: While all four planes can use this arrangement, the Roya-Air . 5
20T and 40T use wooden pushrods while the Great planes PT-20 and : 5
PT-40 should be built with Gold-N-Rods. о”
le
53
a e
Fig. 10-5. Before the wing plates are in place you have to be
gentle with the wing. To test fit the wing, tie rubber bands to-
gether as shown so that they're twice as long as normal. They'll
hold the wing well enough for now and won't exert enough pres-
sure to damage the trailing edge.
к
Sa
"EE
A Ei
A
si
Fig. 10-6. Cut away enough of the cowl
block to allow easy access to the needie
valve with the engine running.
54
— Aierons ———
FIG. 10-7 DIFFERENTIAL AILERON THROW
65°
Use large
servo wheel
À
On the PT-20 and PT-40 you must get much
more up aileron movement than down aileron
movement. To do this drill holes-in a large
servo wheel as shown. The angle A 8 C made
by the pushrod holes A and C and the servo
shaft B should be 65 degrees.
(see Fig. 10-6). If you try to turn the
needle valve with the engine running
and the cutout is too small, you could
stick a finger into the prop (which I can
tell you from experience is not what
you want).
BALANCING THE PLANE
LATERALLY
Be sure the muffler is in place when
you do this.
SERVOS, PUSHRODS, AND
OTHER RADIO-RELATED
INSTALLATIONS
Ignore THE MANUAL and work from
Chapter Four (Preliminary Radio In-
stallation) and Chapter Seven (Final
Radio Installation).
DIFFERENTIAL AILERON
THROW
Because of the large dihedral angle,
these planes wont respond well to aile-
ron commands unless the aileron that
moves up travels farther than the aile-
ron that moves down. To achieve this
differential throw you have to use a
large servo wheel and connect the
pushrods to it as shown in Fig. 10-7.
COMPLETING THE AIRPLANE
See Chapters Five, Six, Seven, and
Eight of THE BOOK.
ADDING WASHOUT
This is a difficult job and the plane
flies well without washout. You can
skip it and still have a good, gentle
trainer. If you decide to use washout,
follow THE MANUAL's instructions.
11. Building the Midwest Aero-
Star 20 and Aero-Star 40
With the f¢Wing exceptions, frame
the Aero-Stnodels according to the
instructions THE MANUAL.
THE TAIL
¿ MANUAL:s directions with
OY Yowll be using CA hinges,
which arnstalled after the plane is
covered? Not mark hinge positions
or cut Ве slots until after covering
the ple See Chapter Six for hinging
detail
~~ THE FUSELAGE
1 fore gluing any parts together,
en; all burrs with your modeling
knand sanding block. If you don't,
ус get weak joints and a crooked
age.
When gluing the balsa triangle
:es that will later support the fire
il to the fuselage sides, position the
t brace so that it covers the line you
ew for it. Position the right brace
ver the rear edge of the line that you
drew for it. This will build in a little
right engine thrust, which is preferable
to left thrust.
3) Don’t get too attached to the pre-
drilled throttle and steering pushrod
holes. Fill them in with five-minute ep-
oxy as Fig. 4-15, page 18, shows. Later
you'll redrill them in slightly different
positions to take the cable pushrods
that replace the solid rods supplied
with the kit.
4) Nose gear bracket: You may have
to sand a bit off the top of the bracket so
it will line up with the pre-drilled
mounting holes. I had to do this on the
Aero-Star 20, but not on the Aero-Star
40.
5) Gluing the fire wall in place:
a. Before you start gluing, check to
be sure that the engine will not have
left thrust when installed. If necessary
add a thin shim to the left side of the
fire wall brace to overcome any left
thrust. If anything, the fire wall should
be canted a degree or less to the right.
109222849
b. Use 30-minute epoxy for this job so
you don’t have to rush it.
c. Once the fire wall’s secured in
place with two pieces of tape, wipe off
excess epoxy with a tissue soaked in
rubbing alcohol. The idea is to keep the
fire wall smooth so that later you can
glue the cowl blocks squarely to it.
6) Anti-slide block: Nowhere in THE
MANUAL does it tell you to install this
item, but you should. Make the block of
Ys" plywood scrap and glue it just be-
hind the wing saddle as shown in Fig.
11-1.
WING CONSTRUCTION
Caution: THE MANUAL suggests that
you may want to fly with the ailerons
disconnected. You just might get away
with it, but it’s not a good idea. Don’t do
it.
FRAMING THE WING
1) Applying the top leading edge
sheeting: Use slow CA for this job, as
55
РА “о
wr es
a E
E
MARA
Tel.
E -
a
* Wingspan: 52%"
x.. Wing area: approximately 472 square inches
a a SPECIFICATIONS FOR THE AERO-STAR 20
Test Plane Specifications
Weight: 65 ounces (4 pounds, 1 ounce)
Wing loading: approximately 19.8 ounces per square foot
Radio: Futaba Conquest 4 channels
Engine: Fox .19 BBRC
-. Propelier: 9/6 Top Flite
Setup Recommendations
Controls: 4 channels — elevator, rudder, throttle, and aile-
ww =
we
Ea -
a
fe
+ your Tx has rate switches and you fly on low rate, you can
Lu dial in control throw changes as needed.
о General Hardware and Materials Sizes
_ Fuel tank: 4 ounces | LC
Wheel collars: %:." a.
_ Engine: .19 t0 .25 two-stroke. Don't use any engine smaller
.. than .19 cubic inch.
,.. Propeller: 9/5 to 9/6
… Spinner: 2"
“ Wheels:
Main Wheels, 2%”
Nosewheel, 2%"
es Fire Wall Hardware
“Quantity Item
#92 4-40 machine screws with washers
“ag 4-40 blind nuts
4 | 4-40 lock nuts with nylon inserts
- (Needed only if you don't tap the engine mount.)
Ds Pushrods
* Quantity item |
6 metal pushrod with 2-56 thread at one end :
(Note: Many of these items are supplied in your kit. Buy
only what isn't provided.) |
| Special Tools
— 4-40 tap and handle (needed only if you tap the engine
- mount)
Fig. 11-1. Install the anti-slide block just behind the wing saddle.
56
”. Control throws: Set these up as suggested in THE Е
+“ ~The ailerons will probably be touchy at first. If so, decrease = '
rons. DO NOT OMIT AILERONS.
Dihedral angle: Set up as directed in THE MANUAL.
On-board electronics and pushrod arrangements: Put the
| y hardware specified in THE BOOK.
Elevator and rudder pushrod type: Wood o
the throw a little at a time with the help of your instructor. If
components in the order THE MANUAL shows but employ
NUAL, |
— Control throws: Set
— Instructor. If your Tx h
Engine: .40 two-stroke
- Propeller: 10/6 o
-— Spinner: 2%"
- Wheels: В
‘ Quantity
8
ci
SPECIFICATIONS FOR THE AERO-STAR 40
° Test Plane Specifications |
ng area: 67£ square inches — o
Weight: 84 OUF.588 (5 pounds, 4 Ounces)
Wing loading; 78 ounces per s“iuare foot
: 31h 3r Seven, 5-
Епо!пе: О. 5. 40 channel (4 used)
Propeller: 10/3 Master Airscrew
Setup Recommendations
rons. DO NOT OMIT AILERONS, = "ote, and aile-
Dihedral angle: tet up as directed in THE MANUAL.
On-board electrizies and pushrod arrangements: Ar-
range componentsas shown in T+ rd-
ware specified in.Tig 800K. THE MANUAL, but use hard-
Elevator and Sa pushrod type: Wood Во
+ rate switches ánd you fly on
rate you can dial in con i throw changes 28 ence low
General Hardwre and Materials Sizes
Fuel tank: 8to 19 ounces” To
Wheel collars: %:" ©
an EEL
Le Fée
ER .
OE a
Main Wheels, 3
Nosewheel, 244" |
| Fire Wall Hayyarg ——
item | Е
4-40 machine says wit |
8 4-40 blind nuts > With Washers
4 6-32 machine scris with washers
4 6-32 lock nuts witaylon inserts (needed
only if you don't tap the engine mow
~~ Pushrods
Quantity a.
6 metal pushrod with 2. thread at one end
— (Note: Many of these items are supph in your kit. Buy
only what isn’ t provided.)
Special Tools
6-32 tap and handle (needed only if you, the engine
mount) |
THE MANUAL says, but à use accel-
erator to be sure the glue gpg » Oth.
erwise you may stand th, all night
waiting. Ш
2) Torque rod installation sta ing
torque rods is a critical st ¿q the
trick is to glue the torque box in
place without getting glue he rods
themselves. THE MANUAL sug. you
apply light oil to the rods befü ing
with CA. I suggest you use Fileum
jelly and do the gluing wit xy,
‘which is less adept at gluing “gur-
faces than CA is. |
Before either gluing anything, np.
plying petroleum jelly on the rod: al
fit each assembly. On my Aero.
the torque rod box was thinner
the trailing edge of the wing. Ton,
=
at
the planes look better, I aligned the top
of the wing with the top of the box and
glued the assembly in that position (see
Fige11-2). That left a bit of an undercut
on the underside of the wing, but at
least it was out of sight.
Once the torque rods have been in-
stalled, check the degree of movement.
The rods should be able to move 45° in |
either direction. If the ‘range is less
than this, lengthen the notches in the
torque rod box or wing trailing edge, or
both, as needed. a.
3) Aileron preparation: You'll have
to drill a hole in each aileron to accept
the torque rod. THE MANUAL tells you to, —
use a %:" drill. That's fine, but once
you've drilled the hole, rock the drill
back and forth to elongate the hole as
shown in the drawing in Chapter Six
(Fig. 6-23, page 39). When you install
the aileron, you'll fill this hole with ep-
oxy, creating a large bearing surface
and decreasing the likelihood that vi-
bration will work the rod loose.
4) Aileron hinges: Don’t mark or cut
any hinge slots until after the plane is
covered. Then use CA hinges and fol-
low the procedure in Chapter Six (Post-
Covering Assembly).
5) Wing hold-down dowels: Replace
the He’ kit dowels with longer ones of
the same diameter. These must project
7" to 1” from each fuselage side.
6) Shaping the wing fairing: Because
you'll be using a wing seating tape
which wasn’t contemplated by THE
MANUAL's authors, you'll need to raise:
the wing slightly while shaping the
fairing. To do this, place a couple of
strips of *%/=" balsa across the wing sad-
dle and tack them in place with a few
drops of thin CA glue before placing
the wing on the saddle. After you've
shaped the fairing, remove the wing
and cut the balsa shims from the
saddle.
ENGINE INSTALLATION
1) Install the engine mount as shown
in THE MANUAL but don't install the ny-
lon tubes for the throttle and steering
pushrods yet.
2) If you intend to tap the engine
mount to take the mounting bolts, heed
THE MANUAL's instructions on mounting
the engine with the following excep-
tion: If youre using an engine larger
than .25 cubic inch, use 6-32 mounting
bolts, not 4-40 bolts. If you plan to se-
cure the engine without tapping the
mount (see Fig. 11-3), follow the in-
structions in Chapter Four (Prelimi-
nary Radio Installation).
COWL INSTALLATION
1) Replace the thick cowl blocks sup-
plied in the kit. Cut your own to the
same shape from Y4"-thick balsa. This
will allow you to use a longer steering
arm, which will make for smoother
ground handling and safer takeoffs.
2) After gluing the cowl blocks in
FIG. 11-2 ALIGNING TORQUE ROD BOX WITH WING TRAILING EDGE
—
if the torque rod box is thinner than the wing trailing edge, align
the torque rod box with the top, not the bottom, of the trailing edge.
f
Fig. 11-3. If you do not tap the engine mount, you will need to retain the mounting bolts
with nylon-insert lock nuts,
place, temporarily install the engine
and muffler. If necessary, trim the cowl
to clear the muffler to allow easy access
to the needle valve when the engine is
running.
NOSE GEAR
One of the few problems with this de-
sign is the short steering arm, which
makes for overly sensitive steering. It
was to make room for a longer steering
arm that I had you install thinner cowl
blocks. Make the arm as long as you
can, and use the outermost available
hole for your steering cable connector.
You'll have to relocate the steering
arm hole in the fire wall to do this,
which is why you filled in the pre-
drilled steering cable hole with epoxy.
See Chapter Four (Preliminary Radio
Installation) for instructions on how to
install the nose gear strut and drill the
cable holes.
BRACING THE STAB PLATFORM
THE MANUAL provides you two options
for gluing the stab to the fuselage.
Choose the stronger option and glue 4"
balsa fillet pieces inside the saddle as
shown in THE MANUAL.
INSTALLING THE STAB
Don’t do this yet. The model is now
framed, so turn to Chapter Four (Pre-
liminary Radio Installation). From this
point on, you'll work almost exclu-
sively from THE BOOK, which explains
stab installation in Chapter Six (Post-
Covering Assembly).
FUEL TANK INSTALLATION
Follow the instructions in THE MAN-
UAL for this procedure.
LANDING GEAR INSTALLATION
See Chapter Six (Post-Covering As-
sembly) for most details on landing
gear installation. However, the Aero-
Star landing gear installation is un-
usual and is potentially susceptible to
problem vibration, so I recommend you
pack the gear struts in silicone glue.
When you're ready to install the gear
for the last time, here's what to do.
First, smear glue over the exposed part
of the landing gear block, then insert
the landing gear legs and coat them
with silicone glue. Finally, with the
glue still wet, screw the cover plate in
place.
DECALS
The Aero-Stars come with nice de-
cals, but they won’t last unless you
fuelproof them. After applying them,
seal the edges with clear polyurethane
paint. Allow at least 24 hours’ drying
time before operating the engine.
57
12. Building the Royal-Air 20T
and 40T
Build the Royal-Air models accord-
ing to the instructions in THE MANUAL
with the following clarifications, addi-
tions, and exceptions.
(No matter what you read in THE
MANUAL, don’t hinge any control sur-
faces until you get to Chapter Six [Post-
Covering Assembly] in THE BOOK.)
JOINING THE WING PANELS
1) Before beginning work on the
wing panels, check them for warps by
laying them out on your flat working
surface. If they hug the bench, all is
well. If one part of a panel is raised by
more ‘than Ув”, you'll need to correct it
w
A
hod
LE
Ye
Le
a y
LE | La
as described in Chapter Eight (Final
Touches). Caution: The covering mate-
rial on these models is extremely heat-
sensitive. Keep the trim iron tempera-
ture as low as possible and try to avoid
heating the covering where it touches
wood.
2) Preparing the spar joiners: When
gluing the spar joiners together, use
epoxy rather than CA glue, and clamp
the pieces with C-clamps or a vise as
shown in Fig. 12-1. Use waxed paper to
separate the parts being glued from the
clamps. Make sure the parts are per-
fectly aligned. If they aren't, you may
not be able to insert the joiner into the
- pe A re »
¥, у й
E
Y a ES |
e ,
Ш | В *
*, } cow y
+ “
43 ba
о Г
LE м
=
6 и
„о °о*® Pa
LA й
Г
В = Li 4 a
+ MOS:
9° 0e... " й no AT
В E и e PEZ A . Ne
“7 ой LEAR ) a
de у a.
КЛАЙ ЕДЫ
РЕД E | a ы Temo
wing panels. Before the glue sets, wipe
off any excess with an alcohol-soaked
tissue. A glob of cured epoxy can also
keep the joiner from fitting.
3) Dry-fitting the spar joiner: Once
the joiner is glued together, mark one
side “front” and draw a vertical center
line on it. Mark one half left and the
other halfright, as in Fig. 12-2. Test fit
the joiner. It should go in all the way to
the center line. If it doesn't, trim the
end until it does. Repeat the procedure
for the other wing panel. Now dry-fit
the two wing panels together over the
joiner. The center ribs should fit flat to-
gether and the leading and trailing
edges of one wing should line up per-
fectly with the leading and trailing
edges of the other wing. If necessary,
trim the joiner to-obtain this fit.
4) Gluing the wing panels together:
This is a two-step operation. First you
glue the joiner into one wing panel and
allow the epoxy to cure. Then you mix
more epoxy and glue the two panels to-
gether over the joiner. Read this sec-
tion from start to finish before starting.
Few feelings are as hopeless as being
slower than your epoxy and ruining
your airplane.
When you've got the procedure down
perfectly and know that everything
you need is within easy reach, mix the
first batch of 30-minute epoxy (don't
use a faster epoxy!). Smear it all over
one half of the joiner and inside the slot
that will accept the joiner. Insert the
joiner into the slot at least to the center
line and jiggle it around a few times to
~ spread the epoxy inside the slot. This is
the most important glue joint in the
~ aircraft, so make sure the epoxy wets
the wood completely, both on the joiner
and in the slot. Remove the joiner, slob-
ber more epoxy into the slot, and smear -
more onto the joiner. Now insert the
joiner into the slot, lining up the center
line with the center rib. Finally, clean
excess epoxy from rib, joiner, wing sur-
face, etc., with alcohol-soaked tissues
and set the assembly aside to cure.
When the glue has completely cured,
mix a second batch of epoxy and glue
the second wing panel over the joiner
protruding from the first panel, using
the same techniques you used for the
first, except that this time you'll smear
epoxy over both center ribs before slid-
ing the free panel over the joiner.
When you're done, clean off all excess
——.
x
®
Ч Do я
чёто 2 PEE
e A———]————————
| a. 2 AE
Led tte 5. ОНО
ee de io ct a Big! m
e De esto) er re ae
и На 1 2 de
Fig. 12-1. Make sure that the parts are lined up, then clamp the spar joiner tightly while
the epoxy cures.
epoxy with alcohol-soaked tissues, then
apply the tape supplied in the kit to the
center joint. Check to be sure the lead-
ing and trailing edges of the two wing
panels are aligned with one another. If
they're not, fix them now. Once the
alignment is right, set the wing aside
and let the glue cure undisturbed.
Fig. 12-3. Strip the center covering from the wing's underside.
5) Reinforcing the wing center sec-
tion: Now and then at any flying field
you'll see a plane start to pull out of a
steep dive only to have the wings fold
from too much g force. The fuselage,
unencumbered by wings, makes like a
powered arrow and buries itself in the
ground as the helpless pilot watches.
FIG. 12-2
\
If the brace doesn’t go in all the way to the
center line in both wing panels, trim the
ends till it does.
To guard against this depressing event,
reinforce the wing center section with
fiberglass cloth. Figures 12-3-12-6 show
you how to do this.
6) Fitting the wing to its saddle: Test
fit the wing on its saddle. It should sit
level with the center trailing edge
butted against the rear of the saddle
and the leading edge against the front -
of the saddle. On my 40T the wing"
didn’t quite fit. If you have that prob-
lem, trim the rear of the trailing edge
center section. This leaves exposed
wood, which you will later need to
fuelproof, along with the dowels and
engine compartment.
7) Shortening the ailerons: The wings
are held in place with rubber bands at-
tached to dowels. As designed, the aile-
rons come perilously close to the dowels
and just might lead to control hangup if
your wing isn’t centered. To be on the
Fig. 12-4. Then cut a strip of lightweight fiberglass to size,
59
Fig. 12-5... .
and glue it in place with thin CA.
FIG. 12-7 SHORTENING AILERONS
„”
ROYAL 20T AILERON 448 ПООНОО
LJ
Cut line — ?
[= 20%"
Remove this section
ROYAL 40T AILERON i TT
Cut line
~
FR 26%" af
Remove this section
safe side, shorten each aileron before
installing it. Be sure to cut the end that
will be closest to the fuselage, not the
tip end! On my 20T I cut the ailerons
down to 20%”, and on the 40T to 2634".
Don’t cut too much off or the torque
rods won't reach the ailerons (see Fig.
12-7).
8) Hinging the ailerons: The leaf
hinges that come with the kit work
fine, but since it takes skill and time to
install them properly (it takes me
about six hours) replace them with CA
60
lage bottom.
hinges, which are hard to ruin and
which can be installed quickly. See
Chapter Six (Post-Covering Assembly)
for hinging procedures, but before you
do, here's one caution about the precut
hinge slots on the wing and tail parts of
your plane. Don't use them! They re too
big for CA hinges. Cut your own slots
to one side of each precut one. Place one
hinge as near as possible to each end of
the control surface and space the others
as evenly as you can between them.
9) Installing the aileron servo: The
EN
añ -
|
+
ve
+
| Et; +
a
Er
1
Fig. 12-6. The rei. forced section should look like this and will be
stronger than be{are you fiberglassed it.
Fig. 12-8. On the 20T the stesring cable goes through the fuse-
procedure in THE MANUAL will work,
but use the method shown in Chapter
Seven (Final Radio Installation). It's
quicker and provides better security
and vibration protection.
THE FUSELAGE (PROBLEM
AREAS UP FRONT)
Fuelproof the fuel tank compartment
and hatch cover with epoxy as shown in
THE MANUAL. Or, if you prefer, you can
use CA glue. While you're at it, check
the fire wall. On both the 20T and 40T
nade
В on ab me pe En, ey йо окт, Марло ко 121 A a CDS ee 7
Be. GENE MBE 2 Soe LT Cato DRA 5
7
WE
SPECIFICATIONS FOR THE ROYAL-AIR 20T
pes — Test Plane Specifications
— Wingspan: 50%”
go Wing area: 437 square inches
Weight: 84 ounces (4 pounds)
Wing loading: 21.1 ounces per square foot
ngine: Royal .25
ropeller: 9/6 Top Flite
Setup Recommendations
ons. DO NOT OMIT AILERONS.
ihedral angle: Set up as directed in THE MANUAL.
alance forward or aft of this point. : x
accompanying illustration.
on't use the pushrods supplied with the kit.
dde
‘find any control overly sensitive, reduce the throw a littie at
E switches, you can just dial in any changes as needed.
vo General Hardware and Materials Sizes —
4 Fuel tank: Use the tank supplied with the kit.
> Wheel collars: %"
~ Engine: .25 two-stroke
- Propeller: 9/6
. Spinner: Use the spinner supplied with the Kit.
… Wheels: You can get by with the wheels supplied inthe kit, -
- but! recommend e ones for the mains.
| Main Wheels: 27”.
Nosewheel: 27"
- Fire Wall Hardware
Use the fire wall hardware supplied in the kit.
Pushrods
Metal with 2-56 thread at one end. Six required.
Note: Many of these items are supplied in the kit. Buy only |
what isn't provided.
Additional Materials
Fiberglass cloth strip for reinforcing wing c center section
Radio component arrangement recommended for Royal 40T, Royal
20T, and Great Planes PT-40. ,
i
Battery Throttle cable Throttle Elevator
Fuel tank Rudder
tf
Recejver
compartment ">
This is how to arrange the radio gear in the 20T fuselage.
itis a tight fit.
adio: Futaba Conquest 6-channels (only 4 4 channels used) "
| ontrols: 4 channels — elevator, rudder, throttle, and aile- |
alance point: 3%" aft of leading edge of the wing. Do not .
n-board electronics and pushrod arrangements: See the =“
levator and rudder pushrod type: Wood. Make your own. -
ontrol throws: Elevator should be 74" to %" in either direc- 6
ion. This is more than THE MANUAL recommends, but you
# - may need it to hold the nose up on landings. Set up the aile- -
<. ron and rudder throws as directed in THE MANUAL. If you
time with your instructor's help. If your Tx has rate |
SPECIFICATIONS FOR THE ROYAL-AIR 40T
Test Plane Specifications
Wingspan: 64”
Wing area: 736 square inches
Welght: 87.5 ounces (5 pounds, 7.5 ounces)
Wing loading: 17.1 ounces per square foot —
Radio: Futaba Conquest 6-channel (use only 4 channels) Se
Engine: Royal 40 E BR
Propeller: 10/6 Top Flite
Setup Recommendations
: Controls: 4 channels — elevator, rudder, throttle, and alle-
+ ! A A
… exactly at this point. .-
- On-board electronics and pushrod arrangements: See! the:
drawing for the 20T. LEE
;” Elevator and rudder pushrod type: Wood. Make your OWN.
— Don't use the pushrods supplied with the kit. я
‘Control throws: Use the throws recommended in THE MAN-. y
reduce them a little at a time with your instructor's help. if x
rons. DO NOT OMIT AILERONS.
— Dihedral angle: Set up as directed in THE MANUAL. Е
Balance point: 4%" aft of the wing leading edge. Balance %
wide Зе E AD 5
UAL. If you find yourself overcontrolling with these throws, - 44
your Tx has rate switches and you fly on low rate, you can 4
— just dial in changes In throw as you need them. - Es: A
o . .General Hardware and Materials Sizes ape С
| Fuel tank: Use the tank supplied with the kit. В
„ Wheel collars: %:" a ed
- Engine: .40 two-stroke A
Propeller: 10/6 A
_ Spinner: Use the spinner supplied with the kit.
Wheels:
with the kit.
Main Wheels: = diameter — not the wheels supplied ;
— Nosewheel: Use one of the wheels supplied in the i
E Fire Wall Hardware
Use the hardware supplied in the kit.
Pushrods
Metal rods with 2-56 thread at one end (6 required).
Note: Many of these items are supplied in the kit. оон; 3
what isn’t provided. ST
Additional Materials a ad
Fiberglass cloth strip for reinforcing center section. Stan- 45
dard steering arm to replace bell crank supplied in К + ==
od
Setscrew goes in front
Bell crank
— i — je —
——Ll
Steering cabie will
go here
|
—
Fuselage bottom
Ya” —-
FIG. 12-9
LOCATION OF STEERING CABLE HOLE ON ROYAL-AIR 20T
61
OA
ped
— a
5 Oe
nuts.
SE rt E E A A of A | A a wr wr am a ww
e——t — Fire wall
7 Engine mount
|_— rätely. it replaces the beil crank supplied.
~~ Pre-drilled pushrod hole. Fill it with epoxy and
Nose gear bracket. May have to relocate. if so, use new blind
+#— Nose gear strut
FIG. 12-10 FIREWALL ATTACHMENTS,
ROYAL-AIR 40T
Steering arm. This item must be purchased sepa-
drill new hole later.
you'll find a pre-drilled hole for the
throttle pushrod. Plug it with five-
minute epoxy. You'll drill a new hole
later in a slightly different position.
The 40T also has a hole for the steering
pushrod. Plug that, too.
At this point THE MANUAL covers fuel
tank installation, but before you worry
about that, install the main landing
gear, which is easy, and the nose gear,
which is more complicated. Install the
main gear first, following the sketches
in THE MANUAL. You might have to ra-
dius the holes in the landing gear block
to get the gear legs to fit properly, but
you shouldn’t have a problem beyond
that. The nose gear and steering arm
assemblies are done differently on the
20T and 40T.
Steering setup on the 20T: On the
20T the steering arm is a bell crank
which fits below the nose gear bracket
and poses no special problems. How-
ever, this plane is unusual in that the
steering cable doesn’t go through the
fire wall, but enters the fuel tank com-
partment through the bottom of the fu-
selage (see Fig. 12-8). Figure 12.9
shows where to drill the cable hole in
the fuselage. Note in Fig. 12-8 that the
cable connector on the bell crank is in-
stalled upside down so it can’t hang up
on the fuselage. Install the nose gear
and bell crank now. You'll connect the
steering cable when you get to Chapter
Four (Preliminary Radio Installation).
Steering setup on the 40T: On my
40T there were a couple of problems.
First, the engine mount and nose gear
mounting bracket were too close to al-
low installation of the steering arm, so
I had to remove the bracket and the
blind nuts behind it, plug the mounting
holes with epoxy, drill new holes just
below the first set, then reinstal: the
mounting bracket using new blind
nuts. Now there was room to get the
steering arm in place, but the arm pro-
vided with the kit was a bell crank
which wouldn't line up with the steer-
Fig. 12-11. You may have to ream the tank opening slightly to fit the clunk through it.
62
ing cable I had to install later. I re-
placed the bell crank with a standard
steering arm, after which all went
smoothly (see Fig. 12-10).
Don’t move the nose gear mounting
bracket on your 40T unless you have
to. However, you will have to replace
the bell crank with a standard steering
arm if you plan to use the cable steer-
ing pushrod I recommend, rather than
the solid rod provided in the kit.
FUEL TANK ASSEMBLY
Reaming the opening: Slip a piece
of fuel line over the end of the tank’s
clunk and see if the clunk will fit easily
into the tank. Don’t force it. You could
get it in and not be able to retrieve it. If
the fit is tight, ream the opening a bit
with one blade of your needlenose pli-
ers, then try again (see Fig. 12-11).
Keep reaming until the clunk will just
slip in without resistance.
Adjusting fuel line length: The sili-
cone fuel line should be long enough
that when you hold the tank with the
front end up, the clunk nearly, but not
quite, touches the bottom of the tank at
the center (see Fig. 3-5, page 14). The
sketches in THE MANUAL that came
with my kit show the clunk too far back
in the tank. It could cause engine prob-
lems in that position, so make sure the
clunk can never quite touch the back of
the tank.
Isolating the tank from vibration:
The fuel tank sketches that came with
my kits show the front end of the tank
pressed against the plywood fire wall.
This is asking for engine trouble. In-
FIG. 12-12 20T RUDDER PUSHROD SLOT
р —
Rudder
pushrod slot Stabilizer
07
Finrudder
Because of an awkardly placed former in the
20T tail, the piacement of the rudder pushrod
slot and the shape of the pushrod are critical.
Cut the slot as shown here. It should be 4”
wide.
stall the tank as shown in Chapters
Four (Preliminary Radio Installation)
and Six (Post-Covering Assembly).
Hold-down dowels: Use longer dow-
els than supplied with the kit. Cut your
own from Ne" stock. They should project
%" to 1” from each fuselage side. See
Chapter Six (Post-Covering Assembly)
on this subject. a |
Engine installations: I didn't believe
the engine installation shown in THE
MANUAL would work, but on the 40T it
did, and just fine. On the 20T the in-
stallation was the same; however, the
mounting screws had a tendency to
loosen up every few flights. I suggest
you apply LocTite to the mounting
screws when you install them for the
last time. The engine-mounting proce-
“dure itself is clearly explained in THE
MANUAL.
Wheel installation: If the wheels fit
their axles too tightly, ream out the
hubs as described in Chapter Six (Post-
Covering Assembly).
THE MANUAL shows only one wheel
collar per wheel. Unfortunately, the
20T main gear axles are so short this is
the best you can do. However, you
should use two collars per wheel on the
20T nose gear and on all wheels on the
40T.
TAIL INSTALLATION
Before installing the tail, complete
the work in Chapter Four (Preliminary
Radio Installation). Then see Chapter
Six (Post-Covering Assembly) for in-
structions on how to do it. You can skip
everything THE MANUAL says on the
subject and follow the procedures in
Chapter Six with this addition: The el-
evator pushrod exits through a small
hole in the rear of the fuselage, which
raises the possibility of control failure
if the clevis should hang up in that
hole. To avoid any problem, cut away
enough of the rear of the fuselage to al-
low the clevis to operate outside the
airplane at all times. On the 20T this
surgery will weaken the fuse sides un-
der the stab, so reinforce those areas
with balsa sheet.
RUDDER PUSHRODS
If you're building a 20T, cut the slot
for the rudder exactly as shown in Fig.
12-12. Otherwise the rudder throw will
be limited by the pushrod hitting a rear
former inside the fuselage.
FINAL RADIO INSTALLATION
Follow the instructions in Chapter
Seven (Final Radio Installation). Ig-
nore THE MANUALS instructions on this
topic.
BALANCING THE AIRPLANE
When balanced at the forward end of
the range given in THE MANUAL, my
planes flew poorly. Balance the 20T
3%" behind the leading edge of the
wing and the 40T 414” behind the lead-
ing edge. Chapter Eight (Final Touches)
provides more on balancing.
63
13. Building the Top Flite
Headmaster
Build the Top Flite Headmaster ac-
cording to instructions in THE MANUAL
with the following exceptions, addi-
tions, and clarifications.
THE WING
Gluing the dihedral brace: THE MAN-
UAL tells you to epoxy the three pieces
of the dihedral brace together and
weight them down until the epoxy
cures, but I recommend a different
method. Clamp them together with C-
clamps or a vise, using waxed paper to
keep from gluing metal to wood. Make
sure all three pieces are aligned, then
clean off excess glue with an alcohol-
soaked tissue and allow the epoxy to
cure (see Fig. 12-1, page 59).
Fitting the dihedral brace: Once the
brace is glued together, mark one side
“front” and draw a vertical center line
on it (see Fig. 12-2, page 59). Mark one
side of the brace “right” and the other
side “left.” Test fit the brace into the
slot in the appropriate wing panel. It
should go in at least to the center line.
If it doesn't, trim the end until it does.
Repeat the procedure using the other
wing panel. Now dry-fit the two panels
together over the brace. The center ribs
should fit flat together and the leading
and trailing edges of one wing should
line up perfectly with the leading and
trailing edges of the other wing. If nec-
essary, trim the brace, slot, or both to
obtain this fit.
Joining the wing panels: This is a
two-part procedure. First you epoxy the
brace into one wing and let the epoxy
cure, then you epoxy the second wing
panel over the brace and flush against
the first panel. Read the entire proce-
dure before you glue anything and as-
semble everything you’ll need within
arm’s reach. Do at least one dry run be-
fore mixing any glue. You'll have a
limited amount of time to get it right,
and if you don't, you could end up with
a useless wing. Here's the procedure.
Mix up a batch of 30-minute epoxy
(don't use a faster epoxy!). Smear some
over the right or left half of the brace
and into the slot in the corresponding
wing. Insert the brace into the slot at
least to the center line and jiggle it
around a few times to get epoxy on ev-
‘ery bit of wood in the slot. If this joint
fails, your plane returns to kit form, so
be sure the epoxy wets all the wood.
Remove the brace, drop more epoxy
into the slot, smear more onto the
brace, then slip the brace back into the
slot, aligning the center line with the
wing center rib. Finally, clean excess
epoxy off the protruding part of the
brace, wing rib, and wing surface with
tissues soaked in alcohol, then set the
assembly aside to cure completely.
Next, using essentially the same pro-
cedure, epoxy the second wing panel
over the brace and flush against the
first panel. The major difference here is
that this time you need to smear epoxy
over both center ribs.
Once the wing halves have been
glued together, check to be sure the
leading edge and trailing edge of the
right wing line up perfectly with the
leading and trailing edges of the left
wing and that the center ribs fit flush
against one another. Cover the center
joint with the tape provided in the kit,
check the alignment one more time,
then set the wing aside to cure. The
easiest way to do this is to stand it on
end in an out-of-the-way corner. Just
da, A
+
4
Зент ен сене еее ©
SPECIFICATIONS FOR THE TOP
FLITE HEADMASTER
Test Plane Specifications
Wingspan: 59%" |
Wing area: 714 square inches
Weight: 92 ounces (5 pounds, 12 ounces) |
Wing loading: 18.6 oz. per square foot = e
Radio: Futaba Conquest 6-channel (4 channels used). -
Engine: K & B .40 two-stroke (but use larger engine)
— Propeller: 10/6 Top Flite
Setup Recommendations
Controls: 4 channels — elevator, rudder, throttle and ae.
rons. DO NOT FLY THIS PLANE WITHOUT AILERONSI - isc
Dihedral angle: Set up as described in THE MANUAL. . ° E
Balance point: Balance ЗУ aft of the leading edge of the se
0 On-board electronics and pushrod arrangements:
Fig. 13-1. It's easier to cut the cowl if you first outline the cut by range these items as shown in the accompanying drawing
drilling 7” holes. not as shown in the photo in THE MANUAL. Do not use the
pushrods provided with the kit; you can make better ones
See потере Four (Preliminary Radio Installation) for
etails. |
Control throws: Set the control throws as recommended ins :
THE MANUAL. The ailerons may be touchy for you. If you finc 0 |
yourself overcontrolling, reduce the throw a little at a time 8
with the advice and assistance of your instructor. If your Ta X
has rate switches and you fly on low rate, you € can just dia |
in throw changes as needed. г
General Hardware and Materials sizes
Fuel tank: Use the tank supplied with the kit.
Wheel collar: %:” ;
- Engine: .45 two-stroke. | used a smaller engine ¢ on mn у
Headmaster, but takeoffs from grass on hot days were dis
~ cey. The plane needs a .45 engine for best performanc
You can and should throttle back after reaching cruising
altitude. 200222
Propeller: 10/8 or 11/6 -
Spinner: Use the spinner that comes with the kit.
Wheels:
Main Wheels: 3"
Nosewheel: 2%”
Fire Wall Hardware
For attaching engine mount and nose gear bracket to fire °
wall, use the hardware provided in the kit. For mounting the
engine, you'll need four 6-32 machine screws with washers В
EN.
and four 6-32 lock nuts with nylon inserts. “+
Pushrods he
Fig. 13-2. Enlarge the hole with your modeling knife until ¡t will Metal pushrods with 2-56 thread at one end (quantity = 5. <
accommodate the engine. Additional Materials ve
Light fiberglass cloth — two small strips for reinforcing the +
tank cover/windshield
Ш — RADIO ARRANGEMENT RECOMMENDED FOR HEADMASTER #
Elevator =
Throttle cable Servo tray Elevator Throttle pushrod :
тт #
Receiver Е
Battery 5
Steering cable sk
ZZ CM
- Fuel tank compartment Former Rudder Rudder pushrod
“~*~ Rather than jam everything in the front of the radio compartment, |
- placed the servo tray behind the former. My plane balanced per-
. fectiy that way.
NOTE: Place the battery as far forward as possible.
Fig. 13-3. The finished opening should fit like this.
PROPERTY OF
PIKES PEAK LIRRARY DISTRICT
65
Fig. 13-7. A finished and ready-to-fly Top Flite Headmaster (far right) and some of the other planes discussed in this book.
be sure you don’t disturb the alignment
in doing so. |
. Preparing the ailerons: To accom-
modate the longer wing hold-down
dowels I recommend, you'll have to cut
Y" off the inner end of each aileron,
Make sure it's the inner end, not the
tip. Do not hinge the ailerons now, and
when you do, replace the hinges sup-
plied in the kit with CA hinges and in-
stall them as described in Chapter Six
(Post-Covering Assembly).
POSITIONING THE ENGINE
ON ITS MOUNT
THE MANUAL says to place the engine
so the rear of the spinner’s backplate is
4%" from the front of the fire wall. The
crankshaft on the engine I used was too
short to give that much room, so I posi-
tioned the engine as far forward as pos-
sible and installed it as described in
Chapter Four (Preliminary Radio In-
stallation). Later, I had to install the
Fig. 13-4. Cut fiberglass strips to reinforce the windshield/tank
cover.
66
plastic cowl farther back on the fuse-
‘lage than the plans called for to clear
the spinner backplate.
AGE CONSTRUCTION
TEERING ARM
NSTALLATION)
FUSE
Don’t install the steering arm and
nose gear when THE MANUAL tells you
to. Follow the instructions in Chapter
Four (Preliminary Radio Installation).
Fig. 13-5. Then, glue them in place with epoxy.
* en
“on my Headmaster kit the fin as » supplied de
‘+ Was too long. | had to trim it as shown be-::
“-fore installation to keep it from interfering
Es with t the ‘elevator pushrod.
Trim off all material
below the dotted line.
E +
COWL MOUNTING BLOCKS
Install these as described in THE
MANUAL.
CARVING THE COWL
Follow the instructions in THE MAN-
UAL and see Figs. 13-1, 13-2, and 13-3.
-— When installing the cowl, allow ¥%" be-
tween cowl and spinner, rather than
the Ys" prescribed in THE MANUAL.
INSTALLING THE
WINDSHIELD/TANK COVER
Before installing this part, reinforce
it with light fiberglass and epoxy (see
Figs. 13-4 and 13-5). Then follow the
installation instructions in THE MANUAL.
INSTALLING THE TAIL
Before installing the tail, complete
the work in Chapter Four (Preliminary
Radio Installation). Then work your
way through Chapter Six (Post-Cover-
ing Assembly) where tail installation
is covered in detail. Ignore everything
THE MANUAL says and rely on THE BOOK.
There is one special problem with the
tail on this plane. At least on the kit I
built, the fin was so long it would have
interfered with pushrod operation had
I installed it “as is.” If you find the
same problem, cut the bottom of the fin
so that when installed it will protrude
below the fuselage top planking by no
more than %" (see Fig. 13-6).
SERVO, PUSHROD, AND
STEERING INSTALLATION
Ignore THE MANUAL on these subjects.
They're covered in Chapter Four (Pre-
liminary Radio Installation) and Chap-
ter Seven (Final Radio Installation).
DON'T USE THE PUSHRODS SUP-
PLIED IN THE KIT. You can make
better ones.
HOLD-DOWN DOWEL
INSTALLATION
Replace the kit dowels with longer
ones. These should be %” in diameter
and should protrude 7" to 1” from each
fuselage side. See Chapter Six (Post-
Covering Assembly) for details.
LANDING GEAR INSTALLATION
For the main gear, follow the in-
structions in THE MANUAL. For the nose
gear installation, see the instructions
in Chapter Four (Preliminary Radio
Installation).
ALL RADIO INSTALLATION
Follow the instructions in Chapters
Four (Preliminary Radio Installation)
and Seven (Final Radio Installation).
FUEL TANK ASSEMBLY
The sketch in THE MANUAL shows the
fuel line inside the tank longer than it
should be. When you hold the tank
with the outlets on top, the clunk
should not quite touch the tank bottom.
See Chapter Three (Miscellaneous Pre-
liminaries) for more detail.
67
Useful Addresses
Academy of Model Aeronautics
1810 Samuel Morse Drive
Reston, VA 22090
Ace Radio Control, Inc.
P, O. Box 511,116 W. 19th Street
Higginsville, MO 64037
| Dave Brown Products
4560 Layhigh Road
Hamilton, OH 45013
Coverite
420 Babylon Road
Horsham, PA 19044
Cox Hobbies, Inc.
1525 East Warner Avenue
Santa Ana, CA 92705
Du Bro Products, Inc.
480 Bonner Road
Wauconda, iL 60084
Futaba Corp. of America
555 West Victoria Street
Compton, CA 90220
Carl Goldberg Models, Inc.
4732 West Chicago Avenue
Chicago, IL 60651
Great Planes Model Manufactur-
ing |
706 West Bradley Stree
P. O. Box 721
Urbana, IL 61801
Hot Stuff/Satellite City
P. O. Box 836, 659 Laguna Drive
Simi, CA 93062
Midwest Products Co.
400 South Indiana Street
P. O. Box 564
Hobart, IN 46342
Pactra Coatings, Inc.
1000 Lake Road
Medina, OH 44256
Rocket City Specialties
103 Wholesale Avenue
Huntsville, AL 35811
Royal Products Corp.
790 West Tennessee Avenue
Denver, CO 80223
Sig Manufacturing Co, Inc.
401-7 South Front Street
Montezuma, IA 50171
Sullivan Products, Inc.
P. O. Box 5166
One North Haven Street
Baltimore, MD 21224
Top Flite Models, Inc.
2635 South Wabash Avenue
Chicago, IL 60616
Windsor Propeller Co.
384 Tesconi Court
Santa Rosa, CA 95401
World Engines, Inc.
8960 Rossash Avenue
Cincinnati, OH 45236
Special thanks to Eric Clapp and the rest of the folks at Doug's Hobbies.
68

* Your assessment is very important for improving the work of artificial intelligence, which forms the content of this project