CORD CLASS F2B | MODEL CONSTRUCTION

Beginners only pilots first, as a rule, “fly” for simple models, is designed for small “cubic capacity” of the engine. They learn to manage to work out a complex aerobatic figures. Over time, performance of simple models no longer satisfy them. There is a desire to build a more serious and heavier the aircraft under the engine more “cubing”. And this is not surprising because in such a model, the flight characteristics much better.

Presented cord pilotage (CL. Р2В) — a sample of how would the transition between simple (small mass under ice-2,5 cm3) and complex (large mass, modular design, fiberglass, engine to 10 cm3). The proposed model is not so complicated but requires a certain experience in the construction and piloting. Its production takes three to six months, depending on the experience of the athlete.

Building the model I recommend to start with the wing. In plan, this trapezoidal shape, symmetrical profile. Ribs — balsa, with a thickness of 2.3 mm, with cut-outs to facilitate and balsa reinforcements in the form of two transverse slats cross-section 2,3×2,3 mm. Longitudinal — grained pine cross-section at the root 7×5 and 7×3 mm at the end. Until the middle of the wing panels (five bays between the ribs, counting from the body) and glued the spar web with Windows of relief. The forehead of the wing balsa plates (pre-soaked in hot water and bent on the mandrel), the lining of the wing, the trailing edge and lining of the ribs have a thickness of 2 mm. the trailing edge of the and its lining to form a U-shaped profile. The law-cavka inner wing (facing the athlete) light weight, and no, she’s also in the zone of junction of the spar loaded twenty grams of lead.

Plating of bearing surfaces — Mylar film with thickness of 0.03—0.04 mm. Console cover two or three times with liquid glue BF-2 and after drying, applied the tape the painted side out. Unsewn portions of the forehead and tip trim the fiberglass with a thickness of 0.02 mm on a parquet varnish, and the joints and other flaws with putty and sanded.

The flaps and stabilizer of the symmetric profile and the keel PLANO-convex. Their design is stacked (thickness of the ribs is 1.5 mm), they covered the balsa with veneer thickness of 1.2 mm and a banded fake veneer thickness of 1 mm. Surfaces are covered with fiberglass of a thickness of 0.02 mm on a parquet varnish.

The fuselage is one of the most labor-intensive elements of the design. It is very important that it was collected without the slightest bias. I advise you to start its production with mustache engine mounts. It is made from beech or hornbeam. Choose straight grained wood, free from knots and ROE. The bars transfer the drawing of motor and process with an accuracy of 0.1 mm. the Span of the front bulkhead to the end of the whiskers easier, making the chisel the sample in the form of a groove in the side surface. After fabrication and verification of items received with the drawing mark and drill holes with a diameter of 4.2 mm for fastening of the engine. They glued the mounting fungi (threaded bushings with shoulders) of the same outer diameter with inner thread M3 and a height of 10 mm.

Control line aerobatic model aircraft

Wing:

1 – ending (balsa); 2 — wire management (cord thread d0,3×4); 3 —head (balsa s2); 4 — shelf side member (pine, root 7×5, on the end — 7×3); 5 — pad rib (balsa s2); 6 — wall of the spar (balsa x2, only to the middle of the wing with Windows of relief between the ribs); 7 toe (pine 4×4); 8 — rib wings (balsa s2,3); 9 — the lining of the wing (balsa s2); 10 — rocking chair (aluminum s3); 11 load (weight 20 g); 12 — Klondike (balsa s10); 13 — pylon flap with a yoke (wire OVS d2,5); 14,23 — end rib of the flap (balsa s2,5); 15 — sewing the back edge of the wing (balsa s2); 16 — rear edge of the wing (balsa 18×6); 17 — rib flaps (balsa s1,5); 18 — the front edge of the flap (balsa 10×6); 19 — a lining of the flap (balsa 1.2); 20 — trailing edge flaps (trim — lime veneer s1); 21 loop hinge flap (3). 22 — strengthening under the loop of the hinge flap (balsa 30x10x5); 24 — the cross rails (balsa 2,3×2,3); 25—loop UPRAVLINNYA (wire OVS d1,5); 26 — axis rocking (wire OVS d3); 27 — bushing with flange (aluminum); 28 — bar (beech 7×6)

Horizontal tail:

1 —the ending of a stabilizer (8×8 balsa); 2 — rib stabilizer (balsa s1,5); 3 — the leading edge of the stabilizer (balsa 10×10); 4 — the rear edge of the stabilizer (balsa 10×5); 5 — strengthening under the loop portion (balsa 25x8x5); 6 — hinge linkage of the Elevator; 7 — pylon rudder with a yoke (wire OVS d2,5); 8— a lining of a stabilizer (balsa s1,5); 9 — a lining of the Elevator (balsa s1,2); 10 — area (balsa s2,5); 11 — Klondike (balsa s6); 12,16 — ending rudder (balsa 6×6); 13 — front edge of the rudder (balsa 8×5); 14 — rib rudder (balsa s1,5); 15 — the trailing edge of the Elevator (Linden veneer s1)

The layout of the model:

1 — boss motor (Linden); 2 — us motor (beech or hornbeam); 3 — rear frame engine mounts (plywood s1.6 layers); 4— compartment fuel tank; 5 — rail frame motor (Linden 4×3); 6—rear frame engine mounts (plywood B1, 4 layers); 7— side panel reinforced with a plywood plate s1; 8 — side panel (balsa s2,5); 9 — the canopy (fiberglass s0,1 …0,2, 4 layers); 10 — pull the flaps (wire OVS d2,5); 11 — pylon flaps (with a yoke); 12 — pull to the steering wheel height; 13 — prosperous fairing (balsa “3); 14 — hangout of the fuselage; 15 — upper fairing (balsa s2,5); 16 Kil; 17 — rudder; 18 — endbox (balsa 9×4); 19 — steering wheel height; 20 — the horn of the Elevator (with a yoke); 21 stabilizer; 22 — bar mount Assembly tailwheel (balsa 30x20x10); 23 — tail wheel d20; 24— hour tail wheel (wire OVS d1,5); 25 — lower fairing (balsa s2,5); 26 — flaps; 27 — wing; 28 — bar mount chassis (balsa 10). 29 — spinner wheels; 30—d44 wheel; 31 —landing gear (aluminum); 32 of the air channel; 33 — hood; 34 — decorative inserts (balsa); 35 — polosamote fairing (balsa s3): 36 — vertical plate of the frame (balsa s2); 37 — the horizontal plate of the frame (balsa s3)

Keel:

1 — the leading edge (balsa 10×8); 2 — rib (balsa s1,5): 3 — vertical rake (balsa s5); 4 — the upper edge (balsa 8×8); 5 — trailing edge (balsa 10×8); 6— the bottom edge (balsa 16×5); 7 — base (balsa s3)

Chassis:

1 — tire (rubber d44); 2 — Radome (fiberglass); 3 — wheel hub (aluminum); 4—bushing (steel tube 4. 5×0. 75); 5 insert (balsa 8x4x3, 3…4 items); 6 — landing gear (aluminum s3); 7 — M3 screw (paste and epoxy); 8 — washer (brass)

Rocking chair assembled:

1 — rocking chair (aluminum s3); 2,3,4 — bushings (brass, bronze); 5 — washer (brass, 4 PC.)

Pull the flaps:

1 — pull (wire OVS s2,5); 2 — tip M2,5 (brass)

Traction Elevator:

1 — tips M2,5 (brass); 2 — limit switches (wire OVS d2,5); 3 — stem pine (d8)

The propeller:

1 — the body of the screw (birch); 2 — lining of amplification (plywood s1)

Fuel tank:

1 — boost pipe; 2 — pipe of the engine; 3 — fuel tube (shut up screw after filling); 4 — manageritalia wall

The front frame engine mounts glued six layers of plywood with a thickness of 1 mm with subsequent revision. Before making the bulkhead tracings on the plywood with all necessary holes, cutouts and studs. Rear bulkhead motor, pre-glued from three layers of plywood, as easy and it adhered to the fourth layer (without relief). Mount collect when you fixed the engine. Ready frames wear grooves on the bars of a motor and installed in accordance with the drawing. All the gluing is produced using the epoxy glue.

Then start making the compartment under the fuel tank. Its bottom and rear wall from balsa wood with a thickness of 2.5 mm. the Upper wall of 1 mm plywood, sanded to a thickness of 0.6—0.8 mm and are glued on the bottom, motor. The inside compartment hang fiberglass with a thickness of 0.02 mm on a parquet varnish. The front boss of the motor is made from basswood on a lathe.

The next stage of work — making the side panels. For this purpose, the balsa plate with a thickness of 2.5 mm and a length of the fuselage, and two plywood boards with a thickness of 1 mm with grooves (coinciding with the spikes spang of outow) and holes for relief. The length of these plates to half the chord of the wing. After gluing the balsa and plywood plates, mark the locations for the wing and stabilizer, and then make the appropriate cut-outs and adjust them to the desired profile. The finished side is glued to Motorama using clothespins, rubber medical bandage and epoxy glue, clothespins simultaneously pull their tail.

The upper and lower garrote made from balsa plates with a thickness of 2.5 mm. Their steam out in hot water and a gauze bandage strapped to a wooden frame, echoing the contours of the fuselage. In the finished gargrota glued polosamota, which are the same as the frames of the fuselage, cut from balsa wood with a thickness of 3 mm.

Then into the hole in the fuselage for the wing and stabilizer insert the control horns for the flaps and Elevator. Further the epoxy glue set the wing (without flaps), stabilizer and mount control system (a rocking chair with attached cables, the traction of the flaps and thrust of an Elevator). To not pull off the control horns on the ends of their hooks put on and soldered brass washers. Then glued the upper and lower gargrota. To customize the top and glued the keel. For the elegance of the model on both sides of the fuselage axis of symmetry of the wing is glued inlays (as a continuation of the wing profile).

On a pre-made wooden pig vyklevyvajut the canopy from fiberglass with a thickness of 0.1—0.2 mm in four layers. Skins, putty, customize the place of its installation on the fuselage and glued. The final stage in the construction of the fuselage — the manufacturer of the engine hood. He was recruited from the balsa plate, which is treated as the outer contour, and in such a way that the thickness of the walls amounted to 2-2,5 mm. the Finished fuselage covered with fiberglass with a thickness of 0.02 mm on a parquet varnish. If necessary, apply putty and sandpaper to bring the surface for painting.

Under landing gear at the bottom of the fuselage cut a groove into which is glued the balsa block with a thickness of 10 mm. landing gear ripped out of the dural plate (D16 or D16T), 3 mm thick, bent for to drawing and give a streamlined profile. Then mark out and drill three holes with a diameter of 3 mm under the mounting screws. The bottom of the fuselage in place, the chassis mark and drill three holes with a diameter of 4 mm and epoxy glue mount mounting fungi. Wheel main landing gear with a diameter of 44 mm, and the tail wheel is 20 mm. consists of three layers of glass, of a thickness of 0.1 mm on a pre-made matrix vyklevyvajut wheel pants. They are collected with the balsa inserts, epoxy glue after the installation of the wheels. The seams are sanded, glued a narrow strip of glass, of a thickness of 0.2 mm, and treated with putty before painting.

The fuel tank is made of tinplate with a thickness of 0.3 mm. His feature-the presence of a special penagaricano wall with six holes of 6 mm diameter. a wall to keep them in tanks large volume that is not foamed fuel. The tank is set up and fixed in the container by using pieces of foam rubber, following the alignment of the supply tube and the axis of the jet engine to its operating mode was identical in both normal and inverted flight. After final Assembly and prepare the surfaces of the model painted. The paint should be resistant to model fuel (aptenia, epoxy or polyurethane enamel).

Pilotage designed for engine “Talka” (single-channel with cross purge) working volume of 7 cm3. Propeller with a diameter of 280 mm and 140 mm step made of birch and covered with fiberglass with a thickness of 0.02 mm on a parquet varnish. Weight-rotor 320 g. If you use a different engine its weight with the screw should be in the range of 320-340 g. In this case, the offset of the center of gravity is minimal and has almost no effect on the flight characteristics of the model. In addition, for best centering of the model suggest the balsa for the wing to take with a density of 0.1—0.12 g/cm3 for the side plates of the fuselage 0,1—0,12, for gargrota 0.1, for the tail of 0.09—0.1 g/cm3.

In conclusion, the propeller must be chosen for the particular engine, which is desirable to boost. Resourceful and powerful motor is the key to successful flights. Fully equipped with fuel tank empty pilotage the cord has a mass of 1200 g. the Model is stable in horizontal flight and quite maneuverable.

V. NEDILKO, candidate master of sports, head of the aeromodelling circle dpsh them..P.Gaidar

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