Dynaflite DYFA2016 User Manual

• F3B-style soarer makes an ideal first aileron model.

• Strong turbulated wing allows winch launching and low-speed sink.

• Rugged, lightweight balsa/life ply construction.

READ THROUGH THIS INSTRUCTION MANUAL FIRST. IT CONTAINS
IMPORTANT INSTRUCTIONS AND WARNINGS CONCERNING THE ASSEMBLY
AND USE OF THIS MODEL.

Dynaflite guarantees this kit to be free from defects in both material and workmanship at the date of
purchase. This warranty does not cover any component parts damaged by use or modification. In no
case shall Dynaflite's liability exceed the original cost of the purchased kit. Further, Dynaflite reserves
the right to change or modify this warranty without notice. In that Dynaflite has no control over the
final assembly or material used for final assembly, no liability shall be assumed nor accepted for any
damage resulting from the use by the user of the final user-assembled product. By the act of using
the user-assembled product, the user accepts all resulting liability. If you are not prepared to accept
the liability associated with the use of this product, return this kit immediately in new and unused
condition to the place of purchase.

BCATP03 Printed in USA Entire Contents © Copyright 1996

WARRANTY

Congratulations and thank you for purchasing the
Dynaflite Bobcat. Once you have learned the basics of
thermal flying, the Bobcat is an ideal "second"
sailplane. With its "flat" wing and ailerons, the Bobcat
is more maneuverable than beginner, two-channel,
rudder-only models so you will be able to chase those
elusive thermals more aggressively. The Bobcat's
relatively thin airfoil makes it penetrate the wind for
competition flying and slope soaring, yet the flat
bottom makes it somewhat of a floater as well. You
can build the Bobcat with a steerable rudder, but only
advanced fliers will be able to take full advantage of
the additional steering capability. The instructions tell

you how to build a steerable rudder or build a fixed,

immovable rudder. You can mount micro, mini or full
size servos in the fuselage, but the ailerons require
either a mini or a micro servo. Most experts will also
use mini or micro servos in the fuselage. The generous
cabin area allows the Bobcat to accept full size,
standard configuration battery packs and receivers.
Let's get started!

2

Your Bobcat is not a toy, but a sophisticated working
model that functions like a full-size airplane. Because
of its performance, if you do not assemble and
operate the Bobcat correctly, you could possibly injure
yourself or spectators and damage property.

To make your R/C modeling experience totally
enjoyable, we recommend that you get assistance
with assembly and your first flights from an
experienced, knowledgeable modeler. You'll learn

faster and avoid risk to your model before you're
truly ready to solo. Your local hobby shop has
information about flying clubs in your area whose
membership includes qualified instructors.

You can also contact the national Academy of Model
Aeronautics (AMA), which has more than 2,300
chartered clubs across the country. We recommend
you join the AMA which will provide you with

insurance coverage at AMA club sites and events.
AMA Membership is required at chartered club
fields where qualified flight instructors are available.
Contact the AMA at the address or toll-free phone
number below.

Academy of Model Aeronautics

5151 East Memorial Drive

Muncie.lN 47302

[phone]

Fax [phone]

1. You must assemble the plane according to the

instructions. Do not alter or modify the model, as
doing so may result in an unsafe or unflyable model.
In a few cases the instructions may differ slightly
from the photos or plan. In those instances the text
should be taken as correct.

2. You must take time to build straight, true and strong.

3. You must install all R/C and other components so
that the model operates properly on the ground and
in the

air.

4. You must test the operation of the model before the
first and each successive flight to insure that all
equipment operates correctly. You must also make
certain that the model has remained structurally sound.

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

Please inventory and inspect all parts carefully
before starting to build! If any parts are missing,
broken or defective or if you have any questions
about building or flying this model, please call us at
[phone] and we'll be glad to help. If you are
calling for replacement parts, please look up the
part numbers and have them ready when calling.

3

REQUIRED SUPPLIES

AND TOOLS

REQUIRED ACCESSORIES

These are the items "not included" with your kit, that
you will need to purchase separately. Items in
parentheses (OSMG2691) are suggested part

numbers recognized by distributors and hobby
shops and are listed for your ordering convenience.
GPM is the Great Planes® brand, TOP is the Top
Flite® brand and HCA is the Hobbico® brand.

4 Channel Aircraft Radio System with 1 or 2
standard, mini or micro servos and 1 mini or
micro servo

2-Meter Hi-Start Launch System
Approximately 2 rolls Top Flite MonoKote®
covering

1 /4" Latex Foam Rubber Padding

(HCAQ1000)

1/16" Foam Wing Seating Tape
(GPMQ4422)
#64 Rubber Bands (1 /4 Ib box - HCAQ2020)

(3 sets) 36" Flexible Cable Pushrod for

Elevator and Ailerons (GPMQ3702)

36" Solid Wire Pushrod Set (optional) for

Steerable Rudder (GPMQ3716)

(1 pc.) 2-56 Nylon Clevis (optional) for

Steerable Rudder (GPMQ3800, pkg. of 2)

(3 pcs.) Standard Solder Clevises (for .074

wire/cable) (GPMQ3810, pkg. of 2)

(1 pc.) 1/16" Threaded Ball Link for Aileron

Servo (GPMQ3842)

(2 pcs.) 2-56 Screw-Lock Pushrod Connectors

(GPMQ3870, pkg. of 2)

These are the building tools and adhesives that you
will need to build your Bobcat.

We recommend Great Planes Pro™ CA and Epoxy

2 oz. Thin CA (GPMR6003)
2 oz. Medium CA+ (GPMR6009)
CA Applicator Tips (HCAR3780)
CA Accelerator (GPMR6035)
30-Minute Pro Epoxy (GPMR6047)
#1 Hobby Knife Handle (XACR4305)

#11 Blades (Qty 100. - HCAR0311) or (Qty.

5-XACR2911)

Hobbico Builders Triangle (HCAR0480) or

similar

Medium T-pins (HCAR5150)

Wax Paper

Electric Drill
Drill

Bits:

1/16",
(or 7/64"), 11/64" (or 5/32")
#1 Phillips Screwdriver
Top Flite Covering Iron (TOPR2100)

Hot Sock'" (for your covering iron, TOPR2175)
Single-edge Razor Blades (100, HCAR0312)
Denatured or IsopropyI Alcohol (for epoxy

clean-up)

HobbyLite" Balsa Filler (HCAR3401)

Bar Sander or Sanding Block and Sandpaper

3/32",

5/32",

3/16",

#36

(coarse, medium, fine grit - see next page)

4

A flat, durable, easy-to-handle sanding tool is a
necessity for building model airplanes. Great Planes
makes a complete range of Easy-Touch" Bar Sanders
and replaceable Easy-Touch adhesive-backed
sandpaper.

• When you see the term "test
instructions, it means you should first position
the part on the assembly without using any

glue. Slightly modify or "custom fit" the part as
necessary for the best fit.

• Whenever just "epoxy" is specified, you may

use either 30-minute epoxy or 6-minute epoxy.
When 30-minute epoxy is specified, it is highly
recommended that you use only 30-minute
epoxy because you will need either the working
time and/or the additional strength.

fit"

in the

For future reference, here's a list of Easy-Touch
Sanders and adhesive-backed sandpaper:

5-1/2" Bar Sander (GPMR6169)

11 "Bar Sander (GPMR6170)

22" Bar Sander (GPMR6172)

12" Roll of adhesive-backed sandpaper,

80-grit (GPMR6180)

150-grit (GPMR6183)

220-grit (GPMR6185)

Assortment pack of 5-1/2" strips (GPMR6189)

Inch Scale

Bar

• Do not throw away any leftover material

after you have completed your Bobcat. Some
small pieces of leftover balsa or plywood are
used during construction.

Balsa Basswood Plywood

until

Metric Scale

5

All the parts in the following steps are die-cut 1/8"
plywood unless otherwise noted. After you remove
die-cut parts from their die sheets, remove slivers
and die-cutting irregularities with a bar sander and

80-grit sandpaper.

1. Unroll the fuselage plan. Reroll it the opposite

way so it will lie flat. Align the side view of the

fuselage plan over a flat building board into which

you can stick T-pins.

Q 2. Lay a piece of wax paper on the fuselage plan

over the joint between the forward and aft fuselage

sides

so

glue

will

not stick

forward right fuselage side over its location on the

plan. Test fit the aft right fuselage side to it. Use
your bar sander to adjust the forward edge of the aft
fuselage side so it accurately aligns with its location
over the plan. Glue it to the forward fuselage side
with medium CA.

to

the

plan.

Pin

the

Q 5. Sand the glue joint on both sides of the
fuselage sides so it is smooth and even.

U 6. Place the fuselage sides together and
accurately align them. Drill 3/16" holes in the
dimples on the left fuselage side for the wing

hold-down dowels.

U 7. Transfer the lines you marked on the inside of
the right fuselage side to the left fuselage side by

marking them on the top and bottom of the left
fuselage side. Draw the lines with a straightedge
and your ballpoint pen.

Q 8. Use medium CA to glue the left and right
fuselage side joiners to the inside of the left and
right fuselage sides, respectively, so their top edges
are 1/16" below the top edges of the fuselage sides.

U 3. Before you remove the right fuselage side from
the plan, use a straightedge and a ballpoint pen to
accurately mark the location of the three formers
onto the fuselage side.

U 4. Remove the right fuselage side from the plan.
Glue the forward left fuselage side to the aft left

fuselage side the same way.

LJ 9. Sand the bottom edges of the joiners so they
are even with the bottoms of the fuselage sides.

CJ 1. Accurately mark the center of the bottom of the
bulkheads. Label them as shown on the plan and in

the photo.

6

D

2.

Optional: Drill a 3/16" hole near the bottom

of bulkheads A and B for an antenna guide tube (not

included). The hole in bulkhead B must be slightly off
center so the guide tube will not interfere with the
tow hook block.

LJ 3. Use medium CA to glue bulkhead A to the
right fuselage side so it is even with the fuse bottom.
Use a small 90 degree triangle to hold the bulkhead
perpendicular to the fuse side while you glue.

Q 7. Use a straightedge and a ballpoint pen
extend the centerline on the top view of the fuselage
plan an additional 9" from the rear of the fuselage

on the plan. Cover the top view of the plan with wax

paper from bulkhead A to bulkhead D.

LJ 8. Position the fuselage on the top view and
accurately align the aft end of the fuselage over the
centerline, then hold it in position with a large T-pin
on both sides. Align the centerline on bulkhead A
with the centerline on the plan. Hold the fuse in
position with a balsa block and T-pins on both sides
of the fuse.

to

Q 4. Remove the die-cut 1/16" balsa

the die sheet and sand off slivers and die-cutting

irregularities. Cut the aft end of the crutch so it
matches the length shown on the plan.

Q 5. Use thin CA to glue the crutch to the right
fuselage side so it is perpendicular and the front of the
crutch overlaps bulkhead A as shown on the plan.

LJ 6. Join the left fuselage side to the right fuselage
side. Accurately align bulkhead A with the lines you
marked on the left fuse side and align the crutch with
the left fuse side. Use medium CA to glue bulkhead
A to the left fuse side.

crutch

from

Q 9. Fit, but do not glue, the rest of the bulkheads

between the fuse sides. Use the "balsa block and
T-pin" technique to hold the fuselage in position so
the centerlines of the formers align with the
centerline on the plan. Hold the fuse sides to
bulkhead D with masking tape.

U 10. Double-check that the formers align with both
the plan and the lines you marked on the inside of
the fuse sides. Also make sure that the bottoms of the
formers align with the bottoms of the fuse sides. Glue
the formers to the fuse sides with thin CA, followed
with medium CA.

7

U 11. Remove the fuselage from your building
board. Sand the bottom so the formers and fuselage
sides are even. Sand the top of the fuselage sides

and the crutch so they are even.

Q 12. Glue the cross-grain sheeting cut from a

1/16" x 3" x 24" balsa sheet to the aft fuselage top.
The cross grain sheeting should extend from
bulkhead A aft to the end of the crutch.

U 13. Use a straightedge to accurately draw a line
with a ballpoint pen down the center of the 1/8" x

2" x 23-7/8" cross-grain plywood sheet. Cut the
sheet to a length of 12-3/4".

LJ 15. Sand the bottom ply sheet so it is even with
the fuse sides.

LI 16. Glue the 1/4" x 3/8" x 4-1/4" basswood
tow hook anchor to the inside of the forward fuse
bottom, between bulkheads A and B with medium
CA. Note that the 1 /4" side of the anchor is the side
that contacts the fuse bottom.

Note: Perform step 1 only if your are an experienced
pilot who will be able to take advantage of
a steerable rudder. Ailerons alone will allow

intermediate fliers to turn the Bobcat properly.

Q 14. Use medium CA to glue the 12-3/4"
cross-grain plywood sheet to the bottom of the
fuselage so the aft edge aligns with the middle of
bulkhead B and the centerline on the bottom sheet
aligns with the center marks on the bulkheads.

LJ 1. Make the slot for the rudder pushrod guide
tube in the rear of the left fuselage side at the
location shown in the photo and on the plan. Use a
3/16" brass tube sharpened at one end, a 3/16"
drill or a hobby knife.

Do not use CA Accelerator while you build the fin.
Residual accelerator may cure the CA you use to

glue on the fin sheeting before you have a chance

to position it.

8

Q 2. Place a sheet of wax paper over the rudder
and fin plan. Build the fin frame from the 3/16" x

1/4" x 24" balsa stick and the 3/16" x 1-3/8" x
24" balsa sheet. Build accurately because the fin
establishes the incidence of the stab.

Q 3. Cut the fin ribs from the 1 /16" x 3/16" x 24"
balsa stick. Glue them in position.

U 4. Remove the fin from your building board and
peel off the wax paper. Carefully sand both sides of

the fin flat.

tip

of the fin

to make sure the grooves are deep enough.

U 8. Glue the tube in place with medium CA. Sheet

the left side of the fin the same way as the right.

Q 9. Sand the tip of the fin so it accurately matches
the plan. Round the leading edge.

U 10. If you will be building a functioning rudder,
mark the location of the hinges on the fin and cut the
hinge slots.

and

in

the cross braces.

Test

fit

the

tube

Q 5. Use a ballpoint pen to mark the left side of the
fin where the elevator pushrod tube (not included,
GPMQ3702) intersects the braces, base and tip.

Q 6. Sheet the right side of the fin with a 1/16" x

3" x 24" balsa sheet. The bottom of the sheet should

align with the bottom of the horizontal 3/16" x 1/4"

"base" portion of the fin. The grain of the sheet

should run parallel to the LE. Use a small piece of

leftover 1/16" balsa sheet for the corner of the fin

the bottom of the

Q 7. Use a MultiPro™ or a hobby knife to cut
grooves for the elevator pushrod guide tube in the

TE.

A nice little piece of workmanship you have there,
isn't it?

at

Q 1. Test fit the fin and the guide tube in the
fuselage. If necessary, trim the aft edge of the 1/16"
balsa crutch and cross-grain sheeting so the TE of
the fin aligns with the end of the fuselage.

U 2. Place a piece of wax paper under the back of
the fuse to protect your workbench. Place weights on
top of the fuselage to keep it from moving around
while you work. Wrap masking tape 1/8" above the
bottom of the fin to keep excess epoxy off the fin.

9

d 3. Apply 30-minute epoxy to the base of the fin,

the top of the fuse sides and all other mating surfaces.

Insert the fin into the fuse. Clamp the fuse sides to the

fin TE with a clothespin. Push a T-pin through the top

sheeting into the LE to hold the front of the fin down.

Immediately proceed to the next step.

Q 4. Make a fillet of epoxy joining the base of the

fin and the fuse. Use a 90 degree triangle to make

sure the fin is perpendicular. Remove the masking
tape before the epoxy cures and do not disturb the

model until the epoxy is fully cured.

Q 4. Glue the front hatch tongue to the bottom
the hatch so half of it protrudes past the front

edge

of the hatch.

U 5. Use a ballpoint pen to mark the inside edges

of the fuse sides on the aft 2" plywood strip.

of

Q 1. Cut two 2" pieces and one 5-3/4" piece from
the remaining cross-grain 1/8" x 2" plywood strip.
Use medium CA to glue one of the 2" strips to the
front of the fuselage as shown on the plan.

Q 2. Use the 5-3/4" plywood strip (which will
become the top of the hatch) as a spacer to glue the
other 2" plywood strip to the aft portion of the
fuselage cabin. Leave a small gap at both ends of the
hatch to provide clearance for the covering material.

U 3. Use the remaining 1/8" x 2" plywood strip to
make two 3/8" wide hatch tongues. The aft hatch

tongue should be the same width as the inside of the
fuse sides at the back of the hatch. The front hatch
tongue should be the same width as the fuse sides at
the front of the hatch.

LI 6. Position the hatch on the fuselage and transfer
the marks to the hatch so you know where to glue the
aft hatch tongue. Glue the aft hatch tongue so 1 /8" of
the tongue extends past the aft edge of the hatch.

Q 7. Fit the hatch to the fuselage by first inserting

the front hatch tongue under the front fuse top. Next,

bend the hatch so you can slip the aft tongue under
the aft cabin top. Sand all the plywood pieces so
they are even with the fuse sides.

10

Skip to

step

11 if you

will

not be

building

the

functional rudder.

Q 8. Cut a 36" outer pushrod guide tube to a length
of 29". Use coarse sandpaper to roughen the
outside so glue will stick. Slide the tube through the
exit slot in the rear of the fuselage until the front of
the tube extends past bulkhead C the same amount
as the elevator guide tube (this should be about
Make sure the rudder guide tube does not interfere
with the fin LE or the elevator guide tube. If it does,
adjust the position of the exit slot until there is
no interference.

2").

LJ 11. Glue the elevator guide tube and the rudder
guide tube (if you have one) to the inside of the
fuselage sides in a few locations with epoxy.

Because of the angle at which the guide tubes enter
the fuselage at the rear, they should naturally contact
the inside of the fuselage sides in a few spots. This is
where you should glue them.

U 12. Sheet the bottom of the fuselage in a cross-grain
fashion with the remainder of the 1/16" x 3" x 24"
balsa sheet you used for the top of the fuselage.

Q 9. Glue the guide tube to the fuselage side in the exit

slot with 30-minute epoxy and microballoons or just
thin CA. If you use thin CA, fill the slot around the guide
tube with lightweight balsa filler such as Hobbylite".

Q 10. Use your bar sander and 80-grit sandpaper to
sand the exit tube and filler flush with the fuselage side.

1-1 13. Cut, but do not glue, a strip of 1/16" x 3"
balsa to fit on the bottom balsa sheeting joining the
aft edge of the bottom ply sheeting as shown on the
plan. Taper the aft edge of the sheet. Glue it
in

position. Use your bar sander and 80-grit
sandpaper to sand the bottom sheeting even with the
fuselage sides and plywood sheeting.

Q 14. Make the tail skid from a piece of leftover
1/8" plywood. You can glue it now to the bottom
sheeting in the location shown on the plan or you
can wait until after you cover the fuselage.

11