AEROBATIC, RC

AEROBATIC, RADIO-CONTROLLEDWe offer the only pilots model championship class F3A built in 1990. She passed the “test” in different Championships and helped the designer master of sports of the USSR Viktor Mandrik become the first in the championship of the RSFSR in 1990, and the national championship to win silver.
One of the features of the model is the possibility of its disassembly. All the details for transportation fit into a “suitcase” size 200X540X900 mm, where both houses the equipment and launching equipment. Weight of fully equipped “suitcase” does not exceed 10 kg.
 
It should be noted the increased flight weight of the model itself — it is equal to 4290 g. Such a large value is fully justified when flying in strong gusty wind, heavy “pilotage” responds less to gusts and atmospheric turbulence. By the way, now abroad, a trend increase in the flight weight models in their class to 4,600 g.
 
Naturally, for such apparatus is required and a more powerful engine. The solution is to use dlinnobaznaya two-stroke motor or in the transition to chetyrehkantnyj working volume of 20 cm3. The proposed model was originally established engine “Moki” Hungarian production. But then it was replaced by the long stroke TC-10 of the company “Master” from the city of Yaroslavl. Comparing both options, it is necessary to note the undoubted advantages over the past. The long stroke engine provides longer vertical in the figures, there was a marked feeling of lightness of flight. Auditory perception was pleasant, and understandably disappeared high frequency components of sound, as TK-10 runs at speeds approximately equal to 12 000 Rev/min. During the debugging of a model, particular attention is paid to the air screw. The parameters 280X250 mm (diameter X pitch), mahogany (gives good results and birch).
Motor mount is mounted on the four M5 screws to the front bulkhead of the fuselage, made of fiberglass STEF thickness 4 mm motor mount Itself is milled out of aluminum. Rubber bushes-shock absorbers made of rubber hose outer diameter 10 mm. the suspension Device of the motor provides maximum ease of adjustment: rotating the screws, it is possible to expose any corners of Vicosa axis of the propeller. For this model, empirically it was found the following optimal values of these angles: 1° down and 5° to the right. The organ pipe is located under the fuselage in an open niche and is supported by a clamp on the front of the chassis. Fitting selection pressure for pressurization of the tank is located in the place of maximum cross-section of the pipe.
 
Fuselage — celeberty. The thickness of the side panels is 5 mm, and it decreases towards the tail to 3.5 mm. the nose part is pasted inside the fiberglass with a thickness of 0.1 mm. Butt the hull is made of fiberglass brand STEF-1.5 and has the four screws that you access during the Assembly and disassembly of the fuselage is through removable lantern and niche resonant exhaust pipe. Half of the fuselage centered in special sleeves. Reliability of communication of frames with balsa elements increased due to the lining of steklodrota and strips of fiberglass.
 
RC model airplane championship class.
RC model airplane championship class.
 
Model disassembled.
The model is unassembled.
 
Central power frame is made of fiberglass STEF-3, riveted to him the attachment points of the wing (D16T) and the nodes of the chassis, a socket with four screws M3. Wing mounted with a single screw M5 steel 30KHGSA (two console — two screws) and accessory screws M4 in the area of the rear edge.
 
Node linkage engine mounts.
Node linkage motor:
1 — frame (glass fiber 3 mm), 2 — engine mount (D16T), 3 — screw M5 (30KHGSA), 4 — spacer, 5 — rubber cushioning sleeve, 6 — washer, 7 — anchor nut M5 8 — M5 lock nuts, 9 — rivet.
Node for the docking of the fuselage.
The abutment of the fuselage:
1 — half of the split frame (identical), 2 — anchor nut, 3 — flange 4 — screw 5 — rivet 6 — Board.
 
The wing is based on the matrix technology, by vacuum molding, using a plastic bag. Wing skin (or rather “panel”) formed by the foam filler (foam stamps PHV, although you can use brands such as SS-4-40 or PS-1-65) and fiberglass (0.06 mm inside and outside) epoxy resin. The thickness of foam selected in the range of 2.5—3 mm, depending on material density. Rib when the power scheme of the wing missing. The longitudinal normal — it shelf made of pine molded into the trim panel, and the entire wing Assembly is glued to the wall of the spar of balsa average density. At the same time put another wall of balsa to support covering at the rear of the profile and falshstena, which subsequently are cut from the finished wing ailerons.
 
Wing profile and a table of the coordinates of the profile.
The wing profile and a table of the coordinates of the profile.
 
Central fuselage mount the wing.
The Central fuselage attachment fitting of the wing:
1 — frame (glass fiber 4 mm), 2 — bottom bracket 3 — upper bracket, 4 — bolt, 5 — connecting plug of the wing, 6 — a wall-pad (glass fiber 1.5 mm), 7 — shelf spar, 8 — spar wall, 9 — unit rack mount chassis, 10 resonance tube, 11 — front of the chassis.
 
Forming half of a panel wing skin.
Forming half panel wing skin:
1 — matrix, 2 — falshstena, 3 — wall, 4 — filler (foam), 5 — the spar web. A — reference plane.
 
Knot hinge of the rudder.
The node of the hinge of the rudder:
1 — figure screw M5 (D16T), 2 — Bush with thread M5, 3 — plate, 4 — plate with a welded sleeve, 5 — boss (balsa), 6 — rudder.
Special attention deserves the work on the attachment points of the wing. Connecting plug priklepyvayut to glass fibre laminate covering the spar with rivets Ø 2,5 mm. the Entire Assembly is glued into the balsa wall of the spar to the pre-recess pine shelves. After curing of the binder shelf in two places shook a strand of Kevlar or nylon. The ailerons are driven by two steering servos placed in the wing volume.
 
The stabilizer and fin are made of packing foam and have the balsa covering. Siding — fiberglass thickness of 0.03 mm. Stabilizer mounted on the fuselage with one screw M2,5; in the area of the Elevator has two guide pin, taped to the side of the fuselage. The abutment of the rudder includes a plate with a welded bushings and pins, so the material for the plates is selected foil glass fiber. When removing the steering, it is sufficient to Unscrew the locking screw and lift the wheel up.
 
The front chassis is made of two titanium plates with a thickness of 2 mm. in the manufacture of the workpiece weld point method, and after profiling the stand perimeter to boil completely. This design allows for small size and weight of the chassis to use any “coarse” of a runway.
 
Vladimir MANDRIKA, master of sports of the USSR, Arsenyev Primorsky Krai

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