AirfoilZ YAK54 User manual

YAK 54 - Full Fuselage
Assembly Manual
Specifications
Wing Span: 40 inches
Wing Area: 350 in
2
Fuselage Length: 35.5 inches
Weight (ready to fly): 19 to 23 oz.
Wing Loading: 7.8 to 9.5 oz/ft
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Designed by Jim Vigani
Version 1.0 – 3/24/08

© Copyright 2008 all rights reserved
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A Tech Hobbies,LLC Company
PO box 301
Edison, New Jersey 08817
Ph: [phone]
Fax: [phone]
Website: www.airfoilz.com
e-mail: [e-mail]
© Copyright 2008 all rights reserved
Limited Warranty
AirfoilZ takes pride in the care and attention given to the manufacture of the components in this
kit. The company warrants replacement of any materials found to be defective for their intended
use prior to their use in the construction of the model, provided the purchaser requests such
replacement within a one year period from the date of purchase, and the part is returned, if so
requested by the Company. No other warranty, expressed or implied, is made by the company
with respect to this kit. The purchaser assumes full responsibility for the risk and all liability for
personal or property damage or injury resulting from the purchaser’s use of the components of
this kit whether assembled or not.
The Company reserves the right to provide a full refund to the purchaser if the model does not
perform as advertised. Any refund is at the sole discretion of the Company.

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Introduction:
Thank you for choosing the YAK 54 airplane. We have taken great care to provide a design and kit
components that, when properly assembled, will give you a high quality model with outstanding
performance. While the assembly is not complicated, the quality and ultimate performance of your
model will depend on the care you take while building. Please read these instructions carefully
and be sure that you understand them before you start. Take care to assemble the components
as shown and in proper alignment. Please note that some of the parts shown may be different
in material from those provided in the kit. The installation of these parts is unaffected by the
material change.
Warning
This radio-controlled model is not a toy and, if operated inappropriately can cause serious
bodily injury and property damage. It is the buyer’s responsibility to assemble the kit correctly
and properly install the motor, radio and all other equipment. The model must always be flown in
accordance with the safety standards of the Academy of Model Aeronautics (AMA).
This model is designed for high performance. While it is reasonably simple to assemble, it is not
intended for the novice flier. Do not attempt to learn to fly with this model! If you are an
inexperienced modeler, we recommend that you get the assistance of an experienced modeler to
help you with the assembly and initial flights. There are many local clubs that can offer help with
assembly and flight instruction. Information on local clubs can be found through the Academy of
Model Aeronautics. The AMA has over 2500 chartered clubs throughout the country. Information
on the AMA can be found at www.modelaircraft.org.
We do not recommend the use of hot glue for mounting components such as servos, control horns,
receivers or speed controls.
Recommended Power System:
This plane has been designed to use a 175 to 250 watt power system. Recommended motors
include the Hacker A20-20L, Scorpion 2215-18, or AXI 2217-16 with a 20 to 25-amp speed
controller, and a 1320 to 2100 mAh, 3S Li-poly battery with a 10x4.7 or 10x5 propeller. Other power
systems with similar capabilities can be used. Performance will vary depending on the specific
power system selected. For information on alternate power systems please visit
http://3dxhobbies.com or your local hobby shop.

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Kit Contents:
Before you start the assembly of this model, check to make sure that there are no missing parts and
that none of the parts have been damaged during shipment. If you have any questions with the
assembly or flying of this model, please contact us and we will be happy to assist you. If you need
replacement parts please provide the model name. The parts included in the kit are shown on the
Part Sheet included with the kit.
Other items you may need that are not included with your kit:
Building Supplies:
In addition to the kit contents, we recommend having the following building supplies on hand to
complete the kit assembly in accordance with this manual.
 Foam safe (odorless) CA
 Foam safe CA “Kicker”
 Thin CA
 Gorilla glue
 5 and 15 minute epoxy
 Double back tape or spray adhesive
 Low tack masking tape (blue painter’s tape)
 Sanding block with 100 grit sandpaper
 Sanding stick or emery board (150 grit)
 Soldering iron and resin core solder

1
/
32
inch and 1/16 inch diameter drill bits
 Exacto knife with #11 blade
 Utility knife
 Small square
 36 inch ruler
 Needle nose pliers

3
/
8
inch diameter brass tubing
 Diagonal cutting pliers
Power and Control Equipment:
The following items are needed to provide power and control function to your model.
 Brushless outrunner motor with radial mount
 4 motor mounting screws
 Brushless motor speed control
 4 micro servos (Hitec HS55 or equivalent)
 3S Li-poly battery pack
 LI-poly battery charger
 4 or 6 channel micro receiver
 Y harness if a 4 channel receiver is used
 3 to 6 channel transmitter

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Making a Sanding Block:
The leading edges of the elevator, the rudder, and both ailerons need to be beveled prior to
installing the hinges. This is best performed by the use of a 2-inch wide by 12 inch long, 100 or 120
grit sanding block or sanding bar. In addition, other areas of the airframe need to be sanded as
shown in this manual to complete the assembly and enhance appearance. If you do not have a
suitable sanding block, one can be easily made by securing a piece of 100 grit sand paper to a 2
inch x 12 inch x ¾ inch wooden block. The sandpaper can be secured to the block using either
double backed tape or spray adhesive. Make sure that the block is flat! A styrofoam block is
great for general sanding of the fuselage and non-beveled edges of the control surfaces.
Figure: 1
Figure: 2
Figure: 3
General Comments on Assembly:
While not difficult to assemble, the YAK 54 kit is intended for persons with some building
experience. As such, the instructions are presented as a simple sequence that, when followed, will
help ensure that the airframe turns out straight and light. Improperly aligned surfaces and
unnecessary weight will only hinder its performance. Apply glue and epoxy in a thin uniform coat,
using only enough to achieve a strong bond. Excess glue or epoxy will only add unnecessary
weight and will not increase the strength of your model. Trial fit all components to ensure fit and
alignment before applying any glue or epoxy. Keeping joints tight fitting will minimize the amount of
glue required and will ensure a strong bond. When gluing foam to foam, or foam to wood, use

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only foam safe CA and foam safe kicker. There are two basic methods that can be used when
gluing flat pieces of foam together such as when gluing the foam doublers to the fuselage skin. The
first method involves applying CA to the smaller part, positioning it in place and then spraying a light
spray of foam safe kicker along the perimeter of the part. The second method involves applying CA
to the smaller part, and lightly spraying the mating part with foam safe kicker. The parts are then
joined.
Use a light touch while sanding. Foam cuts very quickly and excess pressure can limit your ability to
accurately shape the foam. Take extra care not to over sand. Avoid scratching the surface of the
Depron foam.
Graphics:
The YAK 54 comes with printed vinyl graphics. Extra care in cutting out and applying the vinyl
panels will result in a painted look for your plane. Some people prefer to lightly mist the surface with
“Frebreze” before applying the vinyl. This allows the vinyl to be repositioned while applying them.
Fuselage Assembly:
The fuselage assembly on the YAK 54 consists of a plywood and foam crutch assembly covered
with a depron skin.
Fuse Assembly

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Skin Assembly
Crutch Assembly
Follow the steps in the order outlined below to ensure accurate alignment of the
components.

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Step 1
Glue the wing root
doubler in place with
foam safe CA being
careful to ensure the
wing openings are in
perfect alignment.
Tip:
Apply CA to the doubler,
carefully position on the
skin, then lightly spray
kicker along the edges
of the doubler.
Step 2
Using the plywood nose
doubler as a guide, glue
the top front doubler in
place with foam safe
CA.
DO NOT GLUE THE
PLYWOOD NOSE
DOUBLER IN PLACE!
NOTE: The top front
doubler needs to be
positioned 3 mm from
the edge of the skin. An
alignment tab is
provided at the rear of
the part to help ensure
proper alignment.

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Step 3
Glue the lower rear
doubler in place with
foam safe CA.
NOTE: The lower rear
doubler needs to be
positioned 3 mm from
the edge of the skin. An
alignment tab is
provided at the rear of
the part to ensure
proper alignment.
Step 4
Glue the upper rear
doubler in place with
foam safe CA.

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Align the tab on the
upper rear double flush
with the skin surface.
Step 5
Glue the foam stab
support and ply servo
supports in place with
foam safe CA.

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Step 6
Trim off the top front
doubler alignment tab
flush with the upper rear
doubler.
Repeat Steps 1 to 3 for the other skin assembly making sure to make a
LEFT and a RIGHT side version!
Step 7
Dry assemble all the
plywood crutch pieces
and check for fit. The
pieces should snap
together and self align.
If the fit is tight, lightly
sand the notches for a
snug fit.

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Step 8
Glue the plywood crutch
parts and landing gear
mount parts together
with medium CA. Insert
foam formers and glue
in place with medium
foam safe CA. TIP: tack
glue the plywood pieces
in place with thin CA
then re-glue with
medium CA.
Landing Gear Mount
Assembly
Glue the plywood
landing gear mount in
place with medium CA.

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Glue the landing gear
wire support in place
with medium CA making
sure that the holes in
the landing gear mount
align with the opening in
the landing gear wire
support.
Glue the landing gear
wire torsion support in
place with medium CA
making sure the slot in
the support aligns with
the hole in the landing
gear mount. TIP: Insert
a piece of 3/32 wire into
the hole and use as an
alignment guide.

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Glue the landing gear
wire torsion support cap
in place with medium
CA. Repeat for the
other side.
Glue the crutch bottom
support in place with
medium CA.

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Step 9
Test fit the rudder servo
in the crutch. Trim the
opening as necessary to
match the servo.
Step 10
Test fit the skins on the
crutch and check that
the slot in the rear of the
skin mates with the
alignment tab on the
rear of the crutch.

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Step 11
Glue the crutch to one
skin assembly from the
nose to just behind the
wing opening with
medium foam safe CA.
After the glue has set,
glue the skin to the
lower crutch member
from the wing opening
to the rear tab, making
sure the rear alignment
tab is properly seated in
the slot. Make sure the
rear of the upper crutch
does not interfere with
the slot for the
horizontal stabilizer.
Repeat Steps 10 and 11 for the other skin.
Step 12
Glue the rear edges of
the fuselage together
with medium foam
safe CA .

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Step 13
Epoxy the motor mount
in place making sure it
is flush and square with
the motor mount
support. TIP: Mark the
motor mounting hole
locations before gluing
the motor mount in
place.
Step 14
Test fit the turtle deck
filler piece and glue in
place with medium
foam safe CA.

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Step 15
Test fit the canopy
filler piece and glue in
place with medium
foam safe CA.
Step 16
Glue the top cowl skin
in place with medium
foam safe CA. Tip:
Before gluing, lightly
score the backside of
the top skin with an old
ballpoint pen to allow
the foam to be bent
around the nose without
cracking. Pre-bend the
foam before gluing in
place.

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Step 17
Trim the front of the top
cowl piece and glue in a
3/8” wide scrap piece of
3 mm foam for support
with foam safe CA.

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Step 18
Glue the bottom cowl
skin in place with
medium foam safe CA.
Tip: Before gluing,
lightly score the
backside of the bottom
skin with an old
ballpoint pen to allow
the foam to be bent
around the nose without
cracking. Pre-bend the
foam before gluing in
place.
Step 19
Trim the bottom cowl
piece and glue in a 3/8”
wide scrap piece of 3
mm foam for support
with foam safe CA.