At the European Championship has attracted the attention of many athletes' pilotazhka ", designed and built by the Czechoslovak modeler Stanislav Cech. Unusual position of the engine, the increased elasticity in bending detachable wings, simple and effective, excellent "read" in-flight fuselage and a number of design innovations have benefited performance, debugging and flight characteristics of the new Córdoba acrobat: in combination with the high skill of the pilot, they helped win the competition in the class F2B.
Wing
The wings are made by the classical type-setting scheme. Unusual absence of rigid casing front of the console, which, combined with an extremely lightweight spar provides significant bending elasticity of the wing. According to many experienced athletes - pilotazhniki, deflection consoles when the sudden evolution helps to more clearly display the model in a direct flight through vigorous rectification wing on the output of the trajectory shape.
Spar is glued on a flat mounting plate of melkosloynoy, carefully selected pine. Longitudinal section of the shelves at the full scope permanent - 3x5 mm, combines them into one whole wall of the balsa spar constant section 5h27 mm. It uses light grades of wood with a vertical orientation of the fibers. In the central part of the wing spar strengthened bilateral plywood sheathing thickness of 0.8 mm. The responsibility of this assembly is a structural epoxy resin.
All the ribs are made of balsa thickness of 2.5 mm. Blanks stacked, and processed "tapered" to the left and right brackets. Assembling the wings - on a flat-board stocks. Ribs are put on the finished spar, and then are stuck in their grooves technological edge trim, the front section of 3X10 mm, rear - 3x5 mm. The edges are then mounted ballovye section 10x25 mm (front) and 10x4 mm (rear). After the glue has dried up they vyshkurivayutsya wing profile. Ending cut from balsa plates 7 mm thick, about the front edge on them additionally glued small wood trim, allowing to make a smooth transition from the tips to the edge.
Now it's up plywood mounting plates mount rocker control the thickness of 3 mm. They are glued to the spar between the two central ribs of the wing. Mid wing sheathed balsa wood veneer thickness 2 mm, assembly finishes installing node output cord represents a duralumin plate with an elongated hole, into which crackers with tubular holes for ropes. This design allows to select the exit point for both cord separately widely. In the outer part of the wing is set small container for bulk loading console. Method of selection is determined that for the model with this motoustanovkoy and given weight requires 20 grams of ballast.
Vyshkurivayutsya flaps made of light balsa thickness of 10 mm, are mounted on the wing just after the completion of exterior models on nylon loops, as well as elevators. Before the wing skin with paper glued central portion of the thin strip of 60 mm wide fiberglass with epoxy resin.
Fuselage
The fuselage is going to trehmillimetrovyh balsa sidewalls reinforced on the inside of the nose to the trailing edge plywood thickness of 0.8 mm, and the front four web frames cut from quality trehmillimetrovoy plywood. Motor-sawed plywood 6 mm thick on both sides sheathed polutoramillimetrovym fiberglass and glued in the grooves of the first two frames. Between the second and third frames is stitched on top of the fuselage dvuhmillimetrovoy plywood, and bottom - trehmillimetrovoy balm. This forms a compartment for the tank, which is inserted in place with a rectangular cut-out in the left side of the board. In sidewalls sawed a hole in the sand, they cut off the top part is attached to the center section. Between the front and rear mounted trehmillimetrovye rectangular plywood gussets, reinforced fiberglass and duralumin bearing mounting socket. The resulting overhangs are joined with overlays of similar design, mounted in the second and third frames. Through metal jacks are front and rear wing with two screws MOH securely fasten the wing to the fuselage. Under the wing of it is amplified between the sidewalls millimeter plywood, the top of the fuselage is cut out of balsa sticks, hollowed out to a thickness of 3 mm.
The nose is made from scraps of wood, glued to the assembled frame. Detachable part of the fuselage, located over the wing, okantovyvaetsya perimeter thin plywood fastened front pin, part of the opening above the bulkhead, behind - screw MH. Tail frames frame structure built from balsa rails section of 3 x 10 mm for the right between the rear ends of the curved ¬ sidewalls. In conclusion, the fuselage assembly is mounted to the lower part of the cut from 10 mm thick balsa and scrap wood. "Fairing" smoothly into the keel, vyshkurenny balsa thickness of 10 mm. Rudder hung on strips of sheet duralumin, which allows debugging launches pinpoint the desired angle of its deviation. After orbiting the steering wheel tightly sealed.
Horizontal tail
Tselnobalzovoe plumage. Vyshkurivaetsya stabilizer of two plates glued to the "points". After the surface treatment of the workpiece separate, carefully hollow out half and glued together again, now on the entire surface of the joint. The central part of the stabilizer before installing it in the fuselage tied up to a width of 50 mm thin fiberglass. Elevators vyshkurivayutsya NZ plates 10 mm thick. Since the regulator has collected on its trailing edge thickness of 14 mm, produced a pronounced step in the transition to the handlebars. It provides low efficiency rudders at small angles of deviation, which is beneficial to the implementation of the rounded shapes of the complex. At large angles of the same performance rudders restored, and the model performs well abrupt evolution.
Chassis
Tailwheel landing gear, racks front of the main wheels are cut from hardened duralumin 2.5 mm thick. Rack outside the fuselage, lay down on the five millimeter plywood plate between the sides and sealed bearing two sockets with thread M4. The displacement front to back rack fixed installation plates on the power plate, I rely on the subsequent frame fuselage and the additional bulkhead. Wheel fairings were fashioned out of balsa wood, upholstered thin fiberglass and mounted on racks. The diameter of the main wheels 45 mm in the rear for wire dvuhmillimetrovoy stoic installed small wheel.
Management system
The control system must provide a completely free rudder deflection even at full stretch cord, but slack in it should not be. It is also important requirements for the stiffness of individual controls.
Cables connecting the cords with rocking and going inside the wing, have a diameter of 1 mm. They are attached to a shaker with hinged lugs bent of millimeter wire OBC, the joints with cables wrapped in a thin copper wire and carefully propaivayutsya. Rocking axis diameter of 4 mm is packed in two ball bearings and has a length that allows it to be mounted on the wing of the intermediate lever. On the end of the axle diameter of 3 mm, which is worn thrust flaps. Hog the elevators and flaps are bent out of motorcycle spokes with threads on the end of the MOH, which allows the use of threaded okontsovok pick ratio deflection angles of control surfaces, changing them widely. Is well established ratio of one.
Traction flap is made of three millimeter wire; traction elevators - balsa strip round 6 mm diameter carbon fiber reinforced longitudinal carrier wire tip. Attaching carbon fibers is necessary due to the fact that in contrast to the draft adopted has no pilot holes frames, which significantly reduces the effort of friction in the control system.
The exterior finish
The exterior finish begins with gluing the front of the fuselage until the rear bulkhead extra base chassis thin fiberglass. Then the whole model covered three filler composed of talc or baby powder and nitro lacquer. After waiting for the complete drying of the coating, the surface thoroughly vyshkurivaetsya.
Wing tied up thick long-fiber paper, other elements - fine. Exterior trim model took about a hundred and ten hours, which amounted to a good third of the time, who had gone to the manufacturing unit.
Propeller croup consists of the following elements. Engine 'Super Tiger 46 ", the most popular among today spertsmenov - pilotazhnikov. Among the most valuable of its advantages should be noted low weight and the high torque at low revs. By continuous selection were the optimal parameters of the propeller, the engine and the same characteristics as the model: diameter 300 mm, pitch 170 mm, two-bladed propeller. With him on the ground the engine develops 8000 rev / min. Futorka machined new carb, with bore diameter of 6.5 mm. Fuel tank capacity of 90-100 cm3 enough for six and a half - seven minutes of flight.
According to the magazine "Modeller designer".
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