THE ENTRY INTO THE WORLD OF CORD

INTRODUCTION TO THE WORLD OF CORDThere are several schools of learning modeller-certovica. But, unfortunately, they are all designed for conditions when the novice comes to a specialized circle of modeling and there goes all the degrees of perfection of the athlete.
Much harder for Amateur enthusiasts of aircraft modeling. The lack of skill of pilotage is often (almost always!) leads to continuous chain of accidents, which completely fighting off the desire to engage in this kind of technical creativity.
 
Pass with minimal “losses,” the initial stage in the modeling, and drafted a complex of two cord machines, created by S. Panfilov from Georgia. Simple, easy to manufacture appliances, with its good flight characteristics, and that is what is needed for beginners. I hope the publication will be of interest to club members. After all, the microplane with a similar combination of technical properties are useful to them.
 

“Bouzouki”, submitted to the attention of young modelers, and despite its small size, has some good pilot data and may be used not only as a training technique, but also to bring good luck in the competition “juniors”, where used engines 1.5 cm3 and the length of the cord is limited to 10 m. the model design is very simple; for its realization does not require scarce materials.

 

The details of the frame — beam flange and the edge — made of pine. Longitudinal use of the rail cross-section 4X7 mm, the cross section of the front edge 4X4 mm, rear — 4X10 mm. of the Rib (like the Elevator) cut out the fake plates. However, ribs can successfully apply and great “blanks” — student line. The total mass of the model will increase only slightly. Winglets — lip thickness 4…5 mm.

Fig. 1. Simplified model for air combat under the engine MARZ-2.5 million.

Fig. 1. Simplified model for air combat under the engine MARZ-2.5 to

1 — copper tube 2 — ending (Linden or pine of thickness 4…5 mm), 3 — the front edge (pine section 4X4 mm) 4 — shelf side member (pine cross-section 4X7 mm), 5 — wires 6 — rib (lip thickness: 2 mm), 7 — Polonnaruwa (Linden thickness of 2 mm or disciplic line), 8 — wire bracket rocking 9 — rocking, 10 — motor mount (aluminum profile), 11 — power rib beam (pine thickness 4…5 mm), 12 — headscarf 13 — trailing edge (pine cross-section of 4X10 mm), 14 — Elevator (Linden), 15 — center of the rear edge (pine section 5X11 mm) 16 — pylon (plastic), 17 — thrust (steel wire Ø 2 mm), 18 — pad for wiring traction (plywood 1 mm), 19 — wall of the side member (plywood 1 mm), 20 — casing the power unit (1 mm plywood).

 

The Central rib as such on this “bouzouki” no: it is replaced by two spaced wing (rib beams). When you build about halfway between the glued parts under engine boss mounted in it with a threaded tube; the external wing models put the fuel tank, then the whole neutral area is sheathed with plywood with a thickness of 1 mm. of the same material is done and the spar web in the Central part, a reinforcing cycle of main parts. The fuel tank’s volume is about 40 cm3.
 
Right about the ending between the shelves of the spar is glued a piece of lead weighing 15-20 g (pre-fat), and in the left flap — the two copper tubes to the cables of the control system. The last twist of the usual three cords according to the known technology. Plastic rocking chair is placed on the wire bracket, strapped to the rails of the spar thread with glue.
 
The whole Assembly “bouzouki” is epoxy resin. To increase the reliability of the most loaded joints in the corners of the glued corners-kerchiefs. Engine MARZ-2,5 fitted with dural profiles-corners. The tight – Mylar film of medium thickness. The center of gravity of fully equipped models should be 55 mm from the leading edge of the wing.
 

The flight model is most likely a purely training nature and is designed for the conditions of unavailability of such engines, as KMD. Main design option is based on plant MARZ-2,5 with a specially made propeller birch size 220Х150 mm. When installing the modified engine MARZ and the mass of the model is about 450 grams, this small “pilotage” can “twist” almost full aerobatic complex.

 

The basis of the fuselage of the model is the part of the power represented by the plate, is glued from three layers of plywood construction chetyrehkilometrovoy. Back to her podklyuchaetsya foam tail section, top and bottom — power stringers made of pine strips section mm. 3X12 saujanya After harvesting of the fuselage (this operation is carried out in the area from the trailing edge of the wing: the tail thickness should be reduced from 12 to 5 mm) the bow of doosselaere plywood with a thickness of 1 mm, which is partially neglective and foam, and the tail of the fuselage is closed by the boss of lime or sheathed with small pieces of thin plywood.
 
Fig. 2. Training and flight model engine MARZ-2.5 million.
Fig. 2. Training and flight model engine MARZ-2.5 to
1 — foam tip (inside hollowed out to facilitate), 2 — front edge (two rails with a section of 2X10 mm), 3 — the second rail of the T-shaped edge 4 — rib (1 mm plywood), 5 — wires 6 — shelf side member (pine cross-section 4X7 mm), 7 rocking control, 8 — fuel tank (located between the hard skin of the forehead of the wing), 9 — side panel (plywood 1 mm), 10 — power part of the fuselage (plywood 12 mm), 11 — an imitation of a lantern, 12 — stringers (pine section 4Х12 mm) 13 — the foam part of the fuselage, 14 — tail boss or the lining (basswood or thin plywood with two sides), 15 — keel (plywood 1…2 mm), 16 — loop linkage steering, 17 — Elevator (Linden or pine with a thickness of 5 mm), 18 — stabilizer (lime thickness 5 to 6 mm), 19 — flap (plywood thickness of 3 mm, mounting — thread on presence to the trailing edge of the wing), 20 — the Central rib (lip thickness 22 mm) 21 — the trailing edge (pine section 5X7 mm) 22 copper tube for the output wires.
Wing complexity does not exceed the fuselage. Ribs are cut from plywood and millimeter after final profiling easier. Ending foam; Central rib that provides connection to the fuselage, made of Linden wood with a thickness of 22 mm and also lightweight. A longitudinal set of fully pine: leading edge, T, of the two rails 2 X 10 mm, beam flange cross-section 4X7 mm (to the ends of the cross section reduced up to 4X4 mm), rear edge — 5X7 mm. Having some experience in the manufacture of aircraft models can be recommended due to the different lengths of the ribs to set the sweep on the leading edge of the wing in the range of 15 mm. the Entire Assembly is maintained in a plasticized epoxy resin in critical areas are established corners-kerchiefs, their thickness is about 2 mm, material — lime. The flaps are cut from plywood of 3 mm thickness, after machining of the contour they are facilitated. The tight wing — Mylar film.
 
Scheme of control and chassis aerobatic model.
The control circuit and chassis aerobatic models.
 
Stabilizer hewed out of the lime sections with the thickness 5…6 mm as the wheel height, which is further facilitated. After covering Mylar film, these parts are assembled by means of three hinges type “concatenated pin”. Control system, the main geometric parameters of which are indicated on the drawings, includes a rocking chair (material — aluminum), cables (twisted threefold cord), control horns rudder and flaps (plastic) and pull (wire Ø 2 mm). The ease of movement of all parts of the control system must be provided with no backlash in the joints. At the ends of the wing for a single column schema of the chassis still need to mount a protective crutches wire, and in the area of the right wing tip to accommodate a weight of 20 g.
 
S. PANFILOV, G. Marneuli, Georgia

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