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GWS Formosa ARF Author: Eric Henderson | Added: 11/16/2008 INTRODUCTION 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”). CONTENTS 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 trainer. 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 aircraft.) 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. CONSTRUCTION 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 foam. 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 correct. 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. THE WING 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 foam. 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 feathers. THE TAIL FEATHERS 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!) FITTING THE WHEELS 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. RADIO INSTALLATION 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 duration. 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. DECALS 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 decals. 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 quickly. 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. Specifications 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 airframe. 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.
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