Top Flite RC-38 User Manual

RC-38 PHASOAR 035 INSTRUCTION MANUAL

I. INTRODUCTION

The PHASOAR 035 from Top Flite Models,
Inc., utilizes its unique looks and design
to deliver electric-powered performance at
the flying field! All of the latest
technology has been employed in designing
this model, starting with the silent, but
powerful, ASTRO FLIGHT Cobalt 035 Electric
Motor. This motor, with a GRAUPNER 7x3
folding propeller unit and a SR 1000 or
"Magnum" 1250 mAh battery pack (6-cell),
has rocketed our prototype PHASOARS to 700
feet in 55 seconds! This was done up to
five times on a single charge!

Aerodynamically, your PHASOAR has a light,
straight-forward and strong airframe.
There's no need to disassemble the model to
get at the batteries because its single­screw release allows quick access to the
battery pack. This allows you to charge
batteries while still in the pod or remove

them for charging while a second pack is
being used. The full-flying stabilator
allows the model to be quickly and
dynamically trimmed for power-on/power-off
flight. The PHASOAR"s airfoil allows
flying in wind conditions that would ground
most of the flat-bottom types and, yet,
provides a great thermal-hunting glide.
The generous rudder area and the
appropriate polyhedral of the wing panels
allow quick detection of the core of the
smallest thermals for long unpowered
flights.

Finally, the PHASOAR is perfectly sized to let you
take it most anywhere and enjoy true, high­performance electric flight.

IMPORTANT NOTE:

If you are a beginner to the sport of R/C flying,
we would urge you to seek and use experienced
assistance in constructing and- flying this
airplane. All model airplane hobbyists should
remember that:

Flying this or an other radio-controlled model
aircraft is a PRIVILEGE and not a RIGHT and this
privilege begins with the utmost safety
considerations to others and yourself as well. An

TOP FLITE MODELS INC.

2635 S. WABASH AVENUE • CHICAGO, ILLINOIS 60616

R/C model airplane in inexperienced hands has the
potential of doing serious personal or property
damage. These safety considerations start at the
building board by following instructions, seeking
competent help when you are confused and avoiding
short-cuts. These considerations have to be
carried over to the flying field where safety must
come first.

done so, to:

1. Send for and obtain your Academy of Model

We

urge you, if you have not already

Aeronautics (AMA) membership which provides

insurance for your R/C activities'-DO NOT

RELY ON HOMEOUNERS INSURANCE.

2. Join an AMA-sanctioned R/C flying club in
your area where you can obtain experienced
guidance and instruction in trimming and

learning how to fly this model.

Many local hobby shops have the required AMA forms
or can advise how/where they can be obtained.

WARNING!!!

A radio controlled model is NOT a "toy." Care and
caution must be taken in properly building the
model, as well as in the installation and use of
the radio control device. It is important to

follow all directions as to the construction of
this kit as well as installation and use of the
engine and radio gear. The advice and assistance
of a well-experienced builder and pilot is highly
recommended. Don't take chances! Improper
building, operation, or flying of this model could
result in serious property damage and/or in serious
bodily injury to yourself or others.

II. PRE-CONSTRUCTION NOTES

The PHASOAR, like other Top Flite kits, employs the
use of die-cut wood to ease the task of
construction, part fit and identification. Die-cut
parts may be removed from their sheets by first

lightly sanding the back of each sheet before
carefully removing each part. Use a light garnet
paper for the sanding and keep a sharp hobby knife
with a #11 blade handy for assistance in removing
any parts that might not have been completely cut­through by the dies. Parts which oppose one
another must be precisely uniform (such a ribs,
etc.) and should be carefully "matched" after their
removal from the part sheets. Matching is the
process of holding the pieces together with either
pins or tape, or by spot gluing and lightly sanding
the edges of the parts until they are identical. A
sanding block with light garnet paper is most
useful for this.

* Straight-edge, preferably metal, at least 36"

long

* 90" triangle
* Soldering iron, flux (such as HARRIS' Stay-

Clean) and solder (silver)
* Carbide cut-off wheel for wire cutting
* Small power jig-saw, such as a Moto-Saw
* Razor plane
* Tapes, such as masking and cellophane

Our PHASOARS were constructed using a variety of
common hobby adhesives including 5-minute epoxy and
cyanoacrylate (CA). Type of glue used may vary
according to individual preference. However,
during the construction there will be call outs for
certain types of adhesives, and we urge you not to
substitute since doing so could possibly cause
structural problems.

Your flat building surface should be at least large
enough to accommodate the wing, yet be able to
accept pins easily. A product such as Celotex
fiber board works well. Another good surface is a
2' x 4' fiber board ceiling tile.

As with most R/C kits that are constructed from
wood, a selection of tools and accessories greatly
help do the job correctly:

Hobby knife with sharp #11 blades
Single-edge razor blades
T-pins
Sanding blocks in assorted sizes
Sandpaper in various grits
Hand-held hobby saw, such as an X-Acto

* Dremel tool or power drill and assorted drill

bits

Left to right:

*Good quality 2-part 5-minute epoxy
*Good quality, sandable filler
*CA accelerator for CA glue
*Good quality, slow-set CA glue

Lastly, the sequence in which the PHASOAR is
assembled has proven to be the most straight­forward and provides finished components in the
order in which you will need them to progress to

2

the next assembly phase. Maintain the building
order presented here to avoid mistakes.

Spread the plans out on your work surface, cover
them with a clear plastic material, such as the
backing from a roll of MonoKote or plastic wrap,
and commence construction.

III. RADIO SYSTEMS

Our prototype PHASOARS have been tested and flown
using two radio types from different manufacturers.

The first of these radio systems is the one
depicted on the plans. The system consists of a
standard-sized 6-channel receiver (AIRTRONICS
#92262), three micro-servos (AIRTRONICS #94501) and
a standard-sized, internally-mounted switch harness
(AIRTRONICS
system by a 4-cell SR 300 mAh battery pack, fitted
with an AIRTRONICS connector. The servos have been
fitted with the 4-arm servo output arms, with three
of these arms cut-off and the remaining arm trimmed
as shown on the plans.

These three servos drive the rudder, stabilator and
the ON/OFF micro motor switch.

#97001).

Power

is

supplied to

this

fully-proportional, motor controller. Secondly,
the receiver and servos are powered by the motor
battery pack, thus, eliminating the need for a
separate, on-board battery supply for these
components! This means that there is no need for
a micro-switch, the wood mounts, the hardware to
mount these parts and no need for the arming switch
because the FUTABA system has all of these
components built-in. This system is available with
FUTABA's #S-133 servo included. The S-133 servo
has almost the same dimensions as the AIRTRONICS
#501 servo, thus no adjustment to the plans in the
servo area is required. Lastly, this system
includes FUTABA's Attack-4 transmitter which is
equipped with servo-reversing.

The radio system just described is very acceptable
in terms of weight and reliability!

The transmitters we've used in conjunction with the
above system were the AIRTRONICS Championship
Series 6-channel and the AIRTRONICS SR Series 4­channel. Both of these worked well. whatever
system you choose, we suggest that the minimum
requirement is servo-reversing ability.

The second radio system that we've used is made by
FUTABA. This radio system has sophisticated
features that work well in the PHASOAR. First,
when using this system, your servo count goes from
three to two. because the receiver also houses a

FUTABA's System #4NBL 133MN 72 designates the radio
which

will

mentioned.

provide

For comparison, the airborne weight of the FUTABA

system is 3.25 ounces. The AIRTRONICS system
described earlier, with the micro-switch, mounts,
hardware and arming switch weighs or 5.93 ounces.
The difference amounts to 2.68 ounces, or nearly a

10% loss of weight for the model which uses the

FUTABA system!

There are other systems that would also work in the
PHASOAR.

Have whichever radio system selected available for
sizing and fitting purposes during construction.

all

of the

components

IV. MOTOR AND PROPELLER CHOICES

The PHASOAR has been designed and engineered to be
powered by the ASTRO FLIGHT 035 Cobalt motor, using
direct drive. This motor is relatively small,

light-weight (about 130 grams), very powerful for

3

just

its size and quite easy to mount/install. It
swings a 7-3 or 7-4 propeller and accepts a wide

variety of battery packs.

The photograph shows the five (5) battery-pack
types and capacities that we've used to power the
PHASOAR.

There are other motors that will fit into the
PHASOAR's nose, e.g.. the KYOSHO LEMANS 360, the

MABUCHI RS-380SH, and the ASTRO FLIGHT 020 Cobalt,
etc. We must, however, forewarn that these motors

are not going to yield the kind of high-performance
climb-to-altitude that the PHASOAR has been
designed for. Decide now which motor you want to
use

because

during construction.

The propeller choice always tends to be a function
of experience in flying the model. Therefore,
propeller sizes and diameters can and should be
"played with" to determine which one works best.
Our first recommendation is to seriously consider
a folding propeller. Since the PHASOAR is. in non­powered flight, a sailplane, it derives a certain
amount of efficiency by being quite aerodynamically
"clean." while fixed-blade propellers work well,
the folding units tested performed better after
cutting power.

you

will

be

fitting

it

to the fuselage

V. BATTERIES

Your PHASOAR's battery pod has been designed to
carry six (6) AA-sized batteries, or four, possibly
five (if configured appropriately), "Sub C" type
batteries. The capacities of these two battery
types can and do vary and it is important for you
to know at least some of the differences. It is
also important to know that the current drain, when
using the ASTRO FLIGHT 035 Cobalt motor. Is higher
than that of a ferrite-type "can motor." Because
of this, it is appropriate to provide your model
with the best possible set of batteries, both in
terms of capacity and certainly in terms of weight.

Why worry about weight? The single heaviest, FIXED
WEIGHT item that your PHASOAR must carry aloft is
the battery pack. This weight directly influences
the wing loading of the model which dictates how
the model behaves when the power is OFF.

First, on the left in the pod, is the SR 1250 mAh
"Magnum" 6-cell pack. Moving from left to right in
the row of five packs, is another SR 1250 "Magnum"
pack. The next pack shown is the SR 1000 pack,
then the SR 1000 pack in a 5-cell format. Next is
the 4-cell, Sub-C SR 1000 pack, and at the far
right is a 5-cell pack made-up from Sanyo 800
cells. The weights for these units (all with
connectors) are as follows:

These numbers are revealing, especially when tied
into the capacities (potential amount of power) of
each of the packs and their effects on the model's
wing loading. All five of these packs have been
used in testing the PHASOAR and all five have
worked well. The best all-around battery pack has
been the SR 1250 (mAh) 6-cell pack, since it
provides the amount of power that the 035 Cobalt
thrives on. At the same time, it has an acceptable
weight for thermal hunting with the PHASOAR's wing
area (335 sq. inches) and resultant wing loading
(with this pack in place) of 11 ounces/sq. ft.
using the AIRTRONICS equipment or 10 ounces/sq. ft.
when using the FUTABA system.

To get the most out of your PHASOAR, in terms of
flying time, consider obtaining three (3) battery
packs. In this way you can be flying almost
constantly because one pack will be in the model,

one pack will be cooling and the third will be on
charge. With only a single flight pack you could
conceivably have to wait 35 to 40 minutes between
flights.. Be sure to follow manufacturer's
recommendations for recharging the batteries.

SR 1250 6-cell "Magnum" pack. . 7.43 oz.
SR

1000

6-cell

pack

SR

1000

5-cell
SR 1000 4-cell Sub-C pack . . . 6.09 oz.
Sanyo

800

(mAh)

pack

5-cell

......

......

pack . .

7.60

oz.

6.43

oz.

6.52.oz.

VI. BATTERY CHARGERS

There are a great many chargers available for re­charging Nickel-Cadmium batteries (Ni-Cads); too
many to test them all. We have had success with
the two we use and, therefore, recommend these to
you knowing that many others may work out just as
well.

For fast charging (15 to 20 minutes) the LEISURE
#107 AC/DC model works well and can be either used
on your auto's 12-volt battery or plugged into a
110 volt wall socket. Great for quick charges at
the flying field.

For slow charging ACE R/C's DUAL-METERED VARI­CHARGER (#34K32) is available in both kit form and
pre-assembled. It allows two battery packs to be
charged simultaneously. Super when you have the
time at home to top-off the charge in each pack.

4

VII. WING CONSTRUCTION

Be sure and protect your plans by covering them
with backing from a roll of MonoKote or a material
such as clear food wrapping. Take a minute to
study the plans and understand them. We suggest
building a right and left wing panel, starting with
the inboard sections, we'll start with the left
wing first.

1. From the 1/16" x 3" x 30" sheeting
provided, cut, fit and locate over the
plans, the bottom leading edge sheet (use
a long straight edge to develop the correct
width and to true-up the edges). From the
1/8" x 3/16" spruce spar stock provided,
measure and cut the required 15" length for
the bottom spar, set this aside . Now cut
and locate over the plans, the 1/4" x 1"

length of shaped trailing edge stock. Next
cut and glue the bottom center section
sheeting in place to the trailing edge
stock and the forward bottom wing sheet.
Cut, fit and glue in place the six bottom
1/16" x 3/16" cap strips from the stock
provided. Using one of the die-cut W-2
wing ribs as a location guide, the bottom
spruce spar (cut earlier) can now be glued
in place. Lastly, note in the cross
sections that the leading edge of the
bottom wing sheeting needs to be lifted up
and supported in order to match the bottom
contours of the wing ribs, forward of the
spar. This is best done with a length of
trailing edge stock.

2. Note the "tick" marks just in front of and
just behind the wing panel drawings. These
correspond to the rib locations. Use a
straight edge and a soft lead pencil to

mark the rib locations directly on the

leading edge and center section sheeting.

The first wing rib to be installed is the
first W-2 rib, inboard from the polyhedral
break (the inboard end of polyhedral brace
W-10 will butt against this rib when it is

installed). Continuing to work inboard,

toward the center, install the next three
U-2 ribs. From their die-cut sheets,
remove ply dihedral braces W-8 and W-9 and
polyhedral braces w-10 (balsa). The two
remaining inboard w-2 ribs must now be cut
to compensate for the installation of the
W-8 and W-9 dihedral braces; use these
braces as a thickness guide and trim the
ribs as shown on the plans. Finally, root
rib W-1 must also be trimmed into two
pieces to fit in front of and behind the

dihedral braces. Once this is done,

holding W-8 in place again as a guide, glue
all of the remaining forward rib ends in

place to the bottom leading edge sheeting;

remove W-8 from the structure. Using W-9
as a guide, glue all remaining rear rib
ends in place and remove W-9 from the

structure. The remaining outboard W-2 rib
must be trimmed in a similar manner. Using
the same procedure as described, trim this
rib into a front and rear piece and glue in
place using W-10 as a spacer; remove W-10
from the structure.

3. Cut. fit and glue the 1/4" sq. leading edge

in place.

4. Carefully remove this structure from your
work surface. Use a sanding block to
lightly sand the outboard edges (the
polyhedral break) smooth. Place the
structure back on the plans and block up
the center 2-1/2." Using the same
construction as described earlier, the
outer wing panel is now built directly over
the plans and directly to the inner panel.
Take pains to bevel the trailing edge butt
joint for a good fit. Be sure to install

w-10 first before the front and rear
segments of U-2, followed by W-3, W-4, etc.

5. With all of the ribs in place, cut, fit and

glue the top spruce spar in place from W-7
to the W-2 at the polyhedral break. From
your parts bag, locate the bundle of ten
vertical grain shear webs. Carefully trim
one of these to fit between W-3 and W-2 and
against the spars and W-10 with the top
flush with the top of the spar. Once
satisfied, glue this web in place.

6. As shown on the plans, the 1/4" sq. leading

edge must now be sanded down to match the
top contours of the ribs. The razor plane
then sanding block work great here. Once
satisfied, cut, fit and glue in place the
top 1/16" leading edge sheeting (note that
this top sheeting is placed slightly
forward on the top spar thus creating a bit
of a "shelf"). Lastly, cut, fit and glue

in place all of the top 1/16" x 3/16" cap

strips with the exception of the one which
will cover the W-2 ribs at the polyhedral
break. Remove the left wing panel from
your work surface. Use your sanding block
to smooth the outboard face of W-7 in
preparation for the wing tip. Inspect the
bottom polyhedral joint and lightly sand as
needed.

7. The right wing structure is now built using

the same procedures just described.

8. Next, the right and left wing halves will
be joined together. Preparation for this
requires that the two inboard ends of the
wing halves be sanded smooth and beveled
to create a good, straight fit. Do this
now. Pin or weight one of the wing halves
(let's use the left) flat to your work
surface. Next, make sure the rib curve in
the bottom leading edge sheeting is

5

supported with a length of trailing edge
Stock. With everything secure, trial-fit
the right wing half in place with its
polyhedral break supported 2-5/8" off of
the work surface. The resulting butt joint
should be as flush fitting as possible and
the leading and trailing edges of both
inner panels should be straight; take your
time here and ensure that the fit is the
best you can produce, with all parts
lining-up correctly. Once satisfied, apply
a thin, even coat of glue (5-minute epoxy)
to the inboard end of the right wing panel
and carefully fit it to the pinned down

left panel, again making sure the right
panel is raised 2-5/8" at the polyhedral
break. Carefully wipe off any oozing
adhesive. Now, fit W-8 dihedral brace in
place, trimming if needed for a good fit.
Glue w-8 in place. Cut, fit and glue the
left panel's spruce spar in place. Rear
dihedral brace w-9 can now be glued in
place.

below, cut a few scraps of 1/8" balsa to
fill in the leading edge of the wing tip
and glue these in place. From the
remaining 1/16" balsa sheet provided in
your kit, cut. fit and glue in place the
wing tip braces as shown on the plans. On
our prototypes we added these braces top
and bottom.

9. With the left wing still down flat to your
work surface, locate the vertical grain
shear webs (1/16" balsa). Cut, fit and
glue these in place between the remaining

w-2 ribs. out to the polyhedral break.

10. Remove the joined wing structure from the
bench. Pin or weight the right panel in
place to the bench and glue the remaining
top spruce spar in place followed by the
remaining vertical grain shear webs.

11. As you did with the wingtip panels,
carefully shave and sand the inner panel's

leading edges to conform with the top
contours of the wing ribs. Use your
sanding block to lightly sand any high
points on the panel's top surfaces. When
done. the inner panels are ready to sheet.
Pin or weight one side or the other in
place on your work surface. Cut, fit and
glue the leading edge sheeting in place
(again leaving a bit of a "shelf" at the
rear edge of the top spar). Cut, fit and
glue the center section sheeting in place
using the patterns shown on the plans.
Finally, install all of the remaining 1/16"
x 3/16" cap strips out to and including the
polyhedral break. Repeat this procedure
on the opposite wing panel.

12. Locate and remove wing tip parts W-11 from
their die-cut sheets. Sand their inner

edges lightly to render them flat and
straight. Note the tip reinforcement
option shown on the plans. This addition
of a length of 1/8" x 3/16" spar stock
really "beefs-up" an area prone to stress

in an accident. Glue the W-11 wing tips in

place as shown on the plans ("End View of
Wing tip" left panel). Also as shown

The completed wing structure should be carefully
sanded to final shape including the leading edges.

At this point your PHASOAR's wing structure is
nearly complete. Later, after the FUSELAGE
ASSEMBLY, we will insert the forward 3/16" dia. x
1-1/2" hold-down dowel, drill the center section
trailing edge for the hold-down screw and add the
front and rear balsa wing/fuselage fairings.

VIII. STABILATOR CONSTRUCTION

Studying the plans you'll note that the entire tail
group (stabilator, fin and rudder) for your PHASOAR
consists of flat "plate" structures, which have
die-cut "core" parts and die-cut "cap" parts.
These structures are sanded to airfoil shape (shown
on plans) after assembly. Although these
structures are quite straight-forward in design, it
remains important that care be taken in cutting and
gluing the required parts together.

1. From the small parts bag, locate and remove
the single 3" length of 1/16" I.D. aluminum
tubing and two of the four 1/16" dia. x 1­1/2" lengths of music wire (M.W.).
Carefully measure and cut-off four(4) 5/8"
lengths of the aluminum tubing, using a
single-edge razor blade with a rolling
motion on a hard surface. Be sure to save
the remaining 1/2" length of this tubing
for later use.

6