GWS Formosa ARF by liuhongmei


									GWS Formosa ARF
Author: Eric Henderson | Added: 11/16/2008

The GWS FORMOSA ARF is a full-function foam R/C airplane. (GWS stands for “Grand Wing
Systems”). By full-function we mean that it employs four channels that use throttle, ailerons,
elevator and rudder. Its primary construction material is a strong, white molded foam.
The GWS FORMOSA meets all the aircraft requirements of the Academy of Model Aeronautics’
(AMA) Park Pilot Program. The aircraft weighs less than 2 pounds (the Program’s upper weight
limit) and has a level top speed under 60 mph (the Program’s upper speed limit). For complete
Park Pilot aircraft details, follow this link.
The AMA Park Pilot Program offers non-AMA members the opportunity to become AMA
members at a much reduced cost. Park Pilot membership includes a great magazine “Park Pilot”,
$500,000 personal liability insurance, $2.5 million liability insurance for the flying field owner (see
insurance details) and membership in the world’s largest sport aviation association – the AMA.
For complete information and details about Park Pilot membership, just click here.
GWS promotes the FORMOSA as follows: ”GWS brings the fun of precision aerobatics to the
park flying scene with the new F3A Formosa. The Formosa is modeled closely after larger scale
F3A pattern planes and offers extreme aerobatic capabilities. All parts are injection molded for
precise fit, allowing the Formosa to go together easily in about six hours. Styling is F3A design”
F3A is the world Precision Aerobatics level of FAI world-class competition. The airplanes used in
F3A aerobatics are specifically designed to perform smooth and accurate aerobatic maneuvers.
The GWS FORMOSA is a miniature version of these big cousins which usually span around 2
meters (78-5/8”).
                                        Photo 1        Photo 2
The box lid shows a very colorful and sleek-looking airplane. A bold yellow starburst clearly states
that the GWS FORMOSA is intended to be flown by an advanced pilot. The initial question was
going to be what did advanced really stand for? This is a lightweight electric-powered white-foam
airplane that looks like it should fly well and be fairly easy to manage for a pilot just out of a basic

                                        Photo 3        Photo 4

                                               Photo 5
The box also had some really good shots of the GWS FORMOSA in action.
                                      Photo 6         Photo 7

                                              Photo 8
GWS leaves you in no doubt about what you will get and the specifications of their aircraft.

                                              Photo 9
They are also very clear that you will need a transmitter, a receiver, three servos, a battery pack
for the motor and a speed controller. This GWS ARF comes without any radio or flight system.
However, GWS does supply the electric motor, gearbox and the propeller. Most Electric ARF
airplanes do not include these latter items.
                                     Photo 10        Photo 11
The manual contains clear color pictures of the parts and photo-cross-referenced to the
instructions. The photographs really help you to the match the parts.

                                     Photo 12        Photo 13
The box lid shows a really good photo of all of the parts and accurately depicts what you will get
inside the box (photo 13).

                                             Photo 14
The pre-molded fuselage comes in two separate halves. The fin is part of the molding and one
half had the rudder attached to it.

                                             Photo 15
Inside the lid was a somewhat arbitrary warning about the airplane’s being only for use by those
pilots over 14 years old. While written in “Chinese: English, the warning should be heeded as the
Formosa has a very powerful motor spinning an over-sized propeller with authority. (Ed. Note:
There are many RTF airplanes designed just for younger pilots. These are safer than higher
performance Park Pilot airplanes. Sport Aviator will soon be opening a new Section just for such
                                     Photo 16        Photo 17

                                     Photo 18        Photo 19
The wing comes in one piece. Molded into the wings are recesses for a wing spar, the forward
wing retaining pins and the rear 3-mm wing retaining bolt. Two wells are present for the main
landing gear.

                                             Photo 20
The aileron servo is on the top of the wing and the grooves are for the aileron control torque-rods.
At this stage, the ailerons are still part of the wing.
                                            Photo 21
The elevators come molded to the stabilizer and will need to be cut away during the building
process to allow them to be properly hinged.

                                    Photo 22        Photo 23
The canopy is molded separately.

                                    Photo 24        Photo 25
The electric motor comes already fitted to the gearbox. The capacitors to prevent radio-spark
interference have already been soldered into place between the bushes of the motor.

                                    Photo 26        Photo 27
You have a choice of two propellers depending upon what type of flying you prefer. A simple
single beam-mount is used to support the motor assembly.
                                             Photo 28
Hard to photograph, but essential to the construction, are the semi-clear plastic parts, which
make up the control horns and the wheel retainers, etc.

                                     Photo 29        Photo 30
The landing gear and the wire pushrods come pre-bent. The lightweight wheels almost disappear
once airborne.

                                             Photo 31
The engine cowl is made of thin white plastic and is attached to the fuselage with the small
screws provided. The cowl is lightweight (great for 3-D work) and durable (great for 3D work).
                                            Photo 32
There is a small hardware package that contains the wing bolt/retainer nut and the tiny screws for
the cowl, motor mount and landing gear.

                                            Photo 33
The black plastic “Christmas-tree” contains many parts that are not used in this model. The few
that are used are called out in the instruction booklet.
It is probably more economical for GWS to punch out all of the parts onto a common mold, but
the builder must take time and care to identify the correct parts used during construction.

                                    Photo 34        Photo 35
                                     Photo 36        Photo 37

                                     Photo 38        Photo 39
The heart of the GWS FORMOSA is the fuselage. Here are some closer looks at the molding
details. The molded spaces allotted to the servos also can be picked out.

                                     Photo 40        Photo 41
A closer look at the ducting for the cooling air and the slot for the engine’s beam mount.

                                     Photo 42        Photo 43
                                              Photo 44
You can see how the vertical fin and rudder have been molded to line up automatically.

                                              Photo 45
The decal sheet is bold and brightly colored. It should be a welcome addition to the all white foam
color of the airframe. Now that the “tour” of the airframe and kit contents is complete, it is time to
assemble the Formosa.
The Fuselage:

                                      Photo 46        Photo 47
The manual is very good at telling you in what sequence to assemble the GWS FORMOSA. The
photos are clear and the instructions are numbered with reference to the pictures.
The first thing to do is to fit the nylon pushrod guides into the fuselage as shown. Foam-safe
odorless medium CAA was used for this task. Do not use regular CAA as it will damage the foam.
                                      Photo 48         Photo 49
To allow you to put a secure bolt plate in the fuselage to hold the wing in place during flight, a nut
is pre-fitted to a hard plastic plate before the two fuselage halves are joined. The bolt was oiled
first and left in place during the gluing process.

                                      Photo 50         Photo 51
Low-tack blue masking tape was used to hold the fuselage halves together while the GWS glue
cured. Use the GWS supplied adhesive. Make sure to apply some adhesive to the internal
structures that meet internally. When applying adhesive to the outer edges, leave about 1/16 in.
of the outer edge dry to allow the adhesive to spread under pressure without oozing to the
outside and spoiling the airplane’s finish.

                                              Photo 52
Once joined, the two halves of the fuselage automatically lined up the wing bolt mount to exactly
fit the wing’s bolt hole.
                                    Photo 53         Photo 54

                                             Photo 55
The installation of the motor was very straight forward. One small/short screw is used to hold the
gearbox/motor in place on the beam. GWS glue is then used to attach the motor beam to the

                                     Photo 56       Photo 57
A small problem was noticed after the halves had been joined. There was a gap where the fin
joined to the other half. This gap was filled with scrap foam, Glued with foam-safe CAA and then
sanded smooth. The fin could then no longer flex.
                                    Photo 58        Photo 59
The canopy locating pins and plate for the retaining magnet are glued into the molded locations in
the fuselage canopy area.

                                    Photo 60        Photo 61
The bracket placements are matched to the canopy and glued in place.

                                    Photo 62        Photo 63
The magnet to metal plate grip proved to be a little too weak so a second magnet was glued
under the metal plate to improve canopy retention strength. Make sure the magnet polarities are
                                     Photo 64        Photo 65
The cowl is fitted with the motor, propeller and rubber spinner in place for alignment purposes.
Center everything and then tape the cowl in place using low-tack tape. The screw locations could
easily be determined by looking through the thin plastic cowling.
There is a fair amount of modeling work required to get the molded foam wing ready to fly. The
good news is that it only takes a sharp knife and some GWS glue. In general, an extra hinge was
added to give more insurance should one of only two hinges fail.

                                     Photo 66        Photo 67
The GWS aileron torque rod system is quite unique in how it uses tiny rubber grommets to
provide a bearing for the aileron pushrod when it is connected.

                                     Photo 68        Photo 69
The one-piece wing has grooves molded into it that will accept the torque rods for the ailerons.
One servo drives the ailerons. Slots have to be carefully cut into the ailerons’ 45-degree leading
edge to accept the aileron torque wires.
                                      Photo 70         Photo 71
Masking tape is used to hold the ailerons and torque-rod in place for a trial fit. It will be used
again later when the GWS glue has been applied to the hinges.

                                      Photo 72         Photo 73
A fiberglass spar is glued into a groove in the bottom of the wing to provide stiffness to the wing.
Then GWS cement is placed on top of the rod to hold it firmly in place and to help “hide” it.

                                      Photo 74         Photo 75
The ailerons are hinged with the supplied paper hinges. The GWS glue gives you time to position
all of the parts before the glue cures.
                                              Photo 76
A support plate is fitted to the wing. This flat plate prevents the wing bolt from pulling through the

                                      Photo 77         Photo 78
The plastic plate is used to make an accurate impression with points molded into the plastic part.
Then it is glued into the wing using those impressions. This system worked well for both the wing
and the canopy.

                                              Photo 79
The center of the wing fits accurately and snugly into the fuselage leaving no gap.
                                      Photo 80        Photo 81
As can be seen here, the wing seat is a very good fit to the wing. There is no wing rocking on the
wing seat even though only a single bolt is holding the wing in place. The trailing edge gap is the
space for the aileron torque rod.
At this stage, you have assembled the wing enough to use it with the fuselage to line up the tail

                                              Photo 82
The instruction manual was very clear in this area. Steps have to be followed in exact sequence.

                                      Photo 83        Photo 84
The stabilizer alignment could not be attempted until several steps had been followed first! The
fuselage area that is glued to the stabilizer required minor sanding to get everything to sit level
before the final gluing.
                                    Photo 85        Photo 86
To prepare for the alignment process all of the elevator control surfaces need to be cut and
hinged first. The rudder also has to be removed from the fuselage. Then make a 45-degree angle
cut in the leading edge of the rudder to allow hinge movement. The tail wheel assembly is also
fitted at this time to the rudder (Not to the fin!)

                                    Photo 87        Photo 88
Using a very sharp razor blade, the elevators were cut from the stabilizer in one piece. Care has
to be taken to not break the thin piece of foam still connecting the two elevator halves.

                                            Photo 89
Slots were cut and holes drilled to accommodate the wire elevator joiner. The original foam was
left in place as per the instructions.
                                     Photo 90        Photo 91
A small section is cut out of the stern-post to allow you to slide in the stabilizer. (Keep a small
section of foam in a safe place--you will need it later). Only at this stage is the fuselage ready
for you to align and fit the stab relative to the wing position.

                                             Photo 92
The elevators were fitted last, after the stabilizer has been pinned and glued. This was because
they tend to get in the way of the visual alignment process. Notice that the hinge was cut and
marked on the centerline. Use this mark to center the rear of the stabilizer in the fuselage.

                                             Photo 93
The foam section that was removed earlier can then be replaced
                                    Photo 94        Photo 95
The rudder can now be hinged. An extra hinge was fitted for good measure. The tail wheel wire
also provided some hinging at the bottom of the stern-post.

                                    Photo 96        Photo 97

                                            Photo 98
After hinging the rudder, it was found that the elevator halves got in the way. The rudder hit the
elevator before it could swing to the end of its movement range. This happened in both directions.
A new “angle” on the inboard ends of the elevator halves was cut with sharp razor blade to
correct the problem. (Ed. Note: You can also use a sharp razor saw for this. Eric always did like
lots of rudder throw!)
                                     Photo 99         Photo 100
Two plastic brackets are glued into the wells in the bottom of the wing to hold the main front
undercarriage legs. “Gorilla” glue was selected for this task to make it a very strong joint. A whole
night was allowed for this glue to cure before fitting the legs to the brackets.

                                     Photo 101         Photo 102
Two small screws are used to retain the main undercarriage wire leg. The supplied screws were
too small in diameter so thicker ones were substituted. A drop of GWS glue was also used to take
up the wire “slop” in the slot. This prevented unnecessary rattling during flight.

                                              Photo 103
The tail wheel assembly is fitted at the same time as the rudder is hinged. You have to make sure
that no glue gets on the pivot-point of the bracket.

                                              Photo 104
The very lightweight main wheels can be simply fitted to the pre-bent wire using the supplied
plastic retainers. A tiny drop of thin CA will help keep the retainers in place. To prevent the thin
wheels from rubbing up against the wire legs, a separate piece of plastic was fitted to act as a
spacer. This spacing of the wheel from the wire leg also stops the hubs from prematurely wearing
out on the radius of the leg bend.

                                           Photo 105
Three GWS NARO standard micro servos were used to guide the FORMOSA. A GWS 400E F
ESC with BEC was employed to provide power to the radio system and the motor/throttle-control.

                                           Photo 106
These servos were glued in place after being wrapped with clear packing tape.

                                           Photo 107
In keeping with the new spirit of non-interference by park flyer airplanes, the GWS FORMOSA
was guided by a Spektrum 6100 2.4 GHz receiver. This receiver is designed only for Park Pilot
type airplanes.
                                   Photo 108        Photo 109
The supplied 7-cell Ni-MH battery pack was replaced by an E-Flite 800 mAh 2S LIPO to provide
more power and longer flight times. The original battery would have performed well but the
Lithium polymer battery, while more expensive, improves both motor performance and flight

                                           Photo 110
The brushed-motor speed controller needed two “JST” connectors soldered in place to connect to
the battery and the motor. This is a very popular connector for Park Pilot type aircraft

                                   Photo 111        Photo 112
The aileron servo is installed in the center recess and tacked in place with GWS glue. The aileron
servo connects using two short pushrods to the rubber bushed aileron torque rods. The V-bend in
each pushrod was used to accurately adjust the centering of each aileron. (This V-bend
adjustment method is used on the elevator and rudder as well.
                                             Photo 113
Do not forget to install the small screw that attaches the servo’s control arm firmly to the servo!

                                    Photo 114         Photo 115
The radio receiver is placed in the canopy area. The Electronic Speed Control (ESC) is equipped
with a Battery Eliminator Circuit (BEC) that allows the on-board radio system to draw power from
the motor battery. This saves weight; very important in a small electric-powered airplane. The
ESC is tucked into the wing bay area with its own cooling air. Exit holes from the canopy to the
wing bay area allow the power lead for the speed controller to be put up into the cockpit and the
aileron extension lead back down into the wing bay area.

                                    Photo 116         Photo 117
Two GWS Mini servos fit snugly into the pre-molded recesses for the elevator and rudder servos
                                      Photo 118         Photo 119
The elevator and rudder pushrod exits have only a short distance from the fuselage exit to the
control horn. Because of this, care was taken to bend “V” adjustments close to the Z-bends that
go into the horns. The horns had to be flexed with pliers to get the Z-bends into the holes. An
alternative would be to fit the horns after the pushrods had been cut and fitted.

                                      Photo 120         Photo 121
The receiver is inside the wing seat area. The battery slides forward of the receiver into the
cooling duct via the cockpit. It gets air from the from firewall/cowl area. This way, it is easy to fit
and remove the battery pack with the airplane fully assembled.
Without the decals, the GWS FORMOSA is just a plain white “egg” with very little to tell you which
way is up in flight. The decals are not easy to put on, but are well worth the work because they
really do enhance the look of the airplane

                                      Photo 122         Photo 123
The manual is very helpful when it comes to applying the decals. It helps to have these really
good diagrams that not only show the decals, but also has their positions numbered to match the
decal sheet numbers.
                                              Photo 124
The canopy was brush painted grey with water soluble paint. The box showed a blue canopy, but
the kit came with one that was unpainted. Some pilots may want the canopy blue or silver. I had
some grey on hand that really set well against the multi-colored decals.

                                     Photo 125         Photo 126
The big, one-piece, wing decals line up with the leading edge of the wing. The shape of the wing
tips tells you how far out to go. The decals are applied gently/lightly at first. They are only applied
with any pressure when you are sure that they are correctly positioned. (Always stroke the
pressure on the decal from the center towards the outsides to avoid any creasing of the decals
and to eliminate trapped air bubbles.) Remember to slit the clear decal section over the aileron
hinge line.

                                              Photo 127
The stabilizer and elevators are covered in one piece and then the hinge-line released with a
sharp razor blade as on the ailerons.
                                     Photo 128          Photo 129
The decals were applied to the fin and rudder in one piece and then a sharp razor blade was
used to open up the hinge-line. This lines up the stars and stripes perfectly.

                                     Photo 130          Photo 131
The side-decals come in four parts and take quite a bit of planning before you press them down.
Scrap pieces of masking tape were used as guides and positioning points during the process.

                                              Photo 132
Two small separate pieces were provided to join the side stripe on top and the bottom of the
fuselage. This allowed you to “fudge” the join a little if you did not exactly line up the fuselage-side
                                          BUILDING SUMMARY
You only need a few simple tools--a knife and some pliers--and the glue that came in the box.
The tail, fuselage and wing alignment require a bit of modeling knowledge. It is a model that you
could build on a kitchen table. All of the parts fitted well. The center of gravity came out just right
with an 800 mAh 2S LIPO battery all of the way forward in the battery slot. You could fly this
airplane without the decals, but the personality of the bare airframe improves markedly because
of the colorful decals.
                                            READY TO FLY
                                            Photo 133
The GWS Formosa proved to be a light weight airplane. The scale shows it weighs just 14.2
ounces. This is just a bit lighter than GWS claims. The weight reduction might be due to using the
li="Poly" battery.

                                   Photo 134        Photo 135

                                   Photo 136        Photo 137
Here are four views on the grass and ready to go! The Formosa is a very attractive airplane. The
appearance is jet-like while retaining the aerobatic look of a Red Bull Racer
                                            Photo 138
Here is a little peek underneath before taking her up. Clean lines and thin wheels give low drag.

                                            Photo 139
Plenty of cooling air will go in through the cowl opening. This air cools both the battery and ESC.

                                            Photo 140
The finished product poses for the camera on the clubhouse table, ready to be taken out to the
flight-line. The extra time spent on the decals is evident at the flying field.
                                        TIME TO GO FLYING

                                            Photo 141
The GWS FORMOSA airplane will take-off from grass. It is lightweight, powerful and lifts off
                                   Photo 142        Photo 143
Initially the airplane was flown high to set the control trims. Then it was time for low passes to
show off the decals. No trim adjustment was required on the elevator. Two “beeps” of right trim on
the ailerons, and the GWS FORMOSA would fly hands-off.

                                   Photo 144        Photo 145
The GWS FORMOSA is easy to see in the air and photographs well. It was very maneuverable
and goes exactly where you point it.

                                   Photo 146        Photo 147
These flight photographs could just as easily be the ones that were taken from the side of the
box. Instead, they were shot on a calm Fall day with the sun behind the pilot and the camera.
                                               Photo 148
A shallow landing approach and the wheels handle the grass without nosing over.
                                           FLIGHT SUMMARY
A Spektrum DX7 and a 6100 2.4 GHz receiver were used to guide the airplane. The GWS servos
were just right for the job.
This airplane is very easy to fly. The GWS FORMOSA leaves the ground very quickly due to the
angle of attack created by the landing gear.
It will take off in about ten feet from short to medium length grass. The airplane can be hand
launched without any problems.
Please be alert to the potential danger of electric powered models--it is very easy to forget
that the propeller, on an electric motor, can spring to life without any warning. One unintentional
bump of the throttle stick and the propeller will immediately burst into life. It will be spinning very
fast. Keep your hands and other precious parts of your body out of the way. Avoid letting others
get near your propeller.
The GWS FORMOSA is a mini version of a precision aerobatics airplane and it soon shows its
pedigree. It will perform inverted flight. You can perform fast or very slow rolls. The rudder will let
you perform knife edge maneuvers with some aileron correction in the same direction as the
rudder. That means that the Formosa has a little bit of adverse rudder coupling. The airplane
tends to roll in the opposite direction of the rudder input during knife edge flight.
However, the airplane does have a strong rudder response which makes stall-turns and
chandelles easy to do.
The GWS FORMOSA can be flown slowly or quickly. The top speed is not that great, but that is
what you want in an aerobatic airplane. Full power flight times were around six minutes using a 2-
cell 800 mAh 2-S LIPO. A three-cell 3S 1300 mAh LIPO gave a much better vertical, but tended
to drive the propeller too fast at full throttle. You could do some experimenting in this area to get a
better balanced set-up.
                                      PARK PILOT OBSERVATIONS
This airplane will fly well and have no problem performing as a Park Flyer in tight flying spaces. It
could be a practice airplane that you always have assembled in the trunk of your car. Most expert
pilots agree that it is important to fly as often as possible to maintain proficiency. I always try to
follow that advice and you should as well. It may be a strain but try to fly as often as possible.
Despite its small size and light weight, the Formosa is an extremely capable and powerful
performer. It should not be flown indoors unless the arena is stadium sized.
There is now information about a new Formosa II version that is slightly larger (~43 in. span) and
heavier (25 oz.) The newer version is said to be powered by an outrunner brushless electric
motor. More details will follow when available.

Manufacturer: GWS                 Length:     35.9in.
Cost: Less than $100               Wingspan:    35.4 in.
Radio: JR 6200 receiver            Wing Area: 256 sq. in.
Servos: 3 x GWS                   Wing Loading: 8.1 oz. /sq. ft.
Motor: EPS 350C Geared             Weight:      14.2 oz.Airfoil: Symmetrical

Special Airframe Features: Strong molded foam fuselage; colorful decals; fully aerobatic

Notable Positives
Smooth flyer
Small wheels worked on grass
Very good looks with decals
Light flying weight
Good second airplane
Includes geared 370 size motor

Notable Negatives
Could use a little more power for stronger verticals and 3D work.

To top