IN FLIGHT THE GLIDER! | MODEL CONSTRUCTION

“Silver” the world championship of 1981, the same year the first place among the strongest athletes of the USSR — it is the best feature of the scheme boat built by the master of sports of the international class, the repeated champion and the champion of the USSR and the world by A. Tupikina. A similar model was helped by his colleague Vladimir Dovzhenko to be among the winners of the USSR championship in 1982 and set a new record in class-1.

In the design of a boat focused on not so much hydro-how much aerodynamics. The fact that modern microglossary really fly! Enough to climb a small ripple on the water surface, as a model, overclocked to truly aircraft speed, goes to the mode in which it counts only occasionally touches the tops of the highest waves. The rest of the time speed overcomes the distance through the air! Maybe raise the camera higher still, to tear it from hindering the rapid running liquid “bumps”? But… the Rules require sudomodel at least twice in a circle to come into contact with water, otherwise the result will not be counted by the judges.

Try to understand what can be done to reduce air resistance. First is to design the device with the minimum external surface (called the wetted aerodynamics).

That should be “compressed” to Refine? With hood will do nothing, as the size set by the size of the engine and the requirements of the smoothness of the contours. However, it makes sense to remove from the surface any protruding elements such as heads of mounting screws (use hidden), and aerodynamically to properly draw the outlines of the transition of the hood to mount. Here’s a completely unacceptable no ledges or large cracks.

The surface of the pylon can be reduced, of course, not at the expense of strength and stiffness. To solve this problem will help the use of perekleiv thin plywood or light alloy.

Speed sudomodel class b-1:

1 — housing (Linden), 2 — hood (fiberglass), 3 — engine mount (MA-8), 4 — pole (plywood), 5 — resonance exhaust pipe, 6 — the rear wing redan (ДІ6Т), 7 — pipe mounting bracket, 8 — float (balsa), 9 — stabilizer (lime), 10 — headstock frenulum (the second point: of attachment of the frenulum is located in the center of the float).

Fuel tank:

1 — supply pipe, 2 — drain pipe, 3 — tin case.

Templates for the manufacture of a propeller.

Housing cheaper to make highly elongated, needle-shaped. The main purpose of such elongation is the maximum attribute from the model’s center of gravity its stabilizer. The longer the leverage, the smaller the area of the “tail” and in turn, less resistance with excellent longitudinal stability. Significantly and relieved at the same tail. It promotes rapid clearing occurring longitudinal vibrations. A small tail mass will allow not only to shorten the bow of the hull at the same position of the center of gravity, but also “compress” the entire body. After all, the lighter the model, the smaller the volume (and hence surface) casing will be required for the necessary rules for competitions maintaining a fixed machine afloat. This condition limits the reduction of the length of the bow, although her shortening and also leads to increase in longitudinal dynamic stability of the glider. The outlines of the same retannage front of the ledge in any case, change is not necessary. Many years of ship modeling experience has shown that, although this part has poor aerodynamics, hydrodynamics for her even more important. A redan is a good start and great planing.

Area and cross section of the floats drop” prominent forms should be minimal, only allowing the buoyancy of the model.

Important the exterior and interior of the apparatus. Any work aimed at improving the cleanliness of the outer surface will not be excessive. Don’t forget about fairings at all transitions from one subassembly to another. They not only improve the flow but also increase the reliability of the butt joints.

MANUFACTURER MODEL

HOUSING dugout, from symmetrical halves. After the processing of their internal volume adjusted and are Packed frames of the bulkhead and the mounting lugs of the pylon and stabilizer. Docked half, you need to fit the outside hull fiberglass thickness is 0.04 mm, pre-impregnated with epoxy resin ED-5 and ED-6.

HOOD wikiepedia matrix of three layers of glass, of a thickness of 0.1 mm on the same pitch. In the finished “shell” sealed with threaded collets mounts engine mounts engine and a fake boss, securely connecting the pylon with the hood.

Engine mount — magnesium alloy MA-8. After the turning process, the workpiece is almost completely frezeruyutsya one of her rug and the resulting trough details being finalized the seat under the engine.

PILON wood harvesting is a plywood of five layers mm of plywood on epoxy resin, and between individual sheets of a set are laid thin fiberglass. After curing of the adhesive plate is attached to the aerodynamically shaped, symmetrical profile, then finish the pylon is set in the corresponding lugs of the casing and bonnet.

STABILIZER removable, mounted with two screws. It allows you to adjust the installation angle of attack and also facilitates transport of the model. Billet stabilizer planed from Linden, she given a symmetric cross-sectional profile with a maximum thickness of 5 mm, and then the entire part is covered with fiberglass with a thickness of 0,04 mm. In the case of the use of aluminum stabilizer needs to be thinner and 2.5… 3 mm.

Balsa FLOATS are glued to the ends of the stabilizer on the resin ED-5 and ED-6. Small wing-like sponsons, located under the floats cut of aluminum T-shaped profile. They help the tail of the model is not to dig even in relatively high wave with random fluctuations of the housing.

After assembling the glider is painted enamels do not dissolve methyl alcohol. Not preclude the application of paints, nitrocellulose enamels, in this case, it is applied a layer or two of synthetic clear varnish. After viskazivaniya the surface (at nitrobarite this operation complete before varnishing) it is polished. The weight of the finished apparatus is not more than 0.55 kg.

POWERPLANT is the glow engine, both homemade and serial (CSTOM-2,5; “Talca is 2.5”). Good results are obtained with foreign engine “Rossi-15”.

Installation of silencer required. Resonant exhaust single chamber pipe not only helps increase power, but also limits the noise level within 80 dB with orifice diameter of 5 mm.

High speed is achieved using glass fibre laminate two-bladed propeller 0 step 145 and 170 mm; the templates are given on the drawings. The propeller is manufactured by a process previously proposed by the journal (see No. 4, 1979). The blades can be cut and manually controlling the installation angle of their cross sections with the help of some simple devices. But, despite the apparent simplicity and accessibility, the latter method does not provide sufficient accuracy. Proven propellers use as a reference for the manufacture of a form that vyklevyvajutsja steklovoloknistye composite propellers.

POWER SYSTEM means a lot in the fight for high speed. Recently widely used fuel tanks with a supercharger, which will take the pressure from the crankcase of the engine, the resonance tube, or both “sources” at the same time. But this model is applied to the conventional single-chamber “drinker”, which ensures the stable operation of the motor during the race. Tank tinplate or sheet metal “stainless steel” thickness of 0,2—0,3 mm. Drainage and feeding tubes, copper Ø 2.5 and 2 mm, respectively. In the hood the tank is positioned so that the cut of the drain tube is located at the same distance from the plane of symmetry of the model, as the outlet of the nozzle. The exact position is determined during the test of the passing distance, so we need to consider the possibility to move the tank along the transverse axis of the hood.

Commissioning of the system power need with “easy” air screw that will correctly identify the need to tuning the engine or move the tank.

Before the first start check the position of the center of gravity n the correctness of the choice of the parameters of the bridle. The center of gravity of the complete microglitter should be approximately on the leading edge of the pylon. Length shoulder bridle (its total length is 1222 mm) is chosen depending on many factors, the goal is the selection of the one — force model, which was released on mode, move parallel to the surface of the water exactly at a tangent to the circumference of the race. In this case, note that the height of the Central pillar, which is mounted suspended on a rope, Ø 0.5 mm high-speed, set within a 450… 900 mm. and indeed the cord, as it may be thin, still blown back the oncoming flow of air. Therefore, the vanishing point of the shoulders of the bridle (it’s a suspension point on a rope) should be shifted relative to the center of gravity of the machine up and back. Only then can the resistance of water and air movement velocity model will be minimal.

A. TUPIKIN, master of sports of international class, Izmail, Odessa region

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