RIBBON INSTEAD OF A PARACHUTE

RIBBON INSTEAD OF A PARACHUTEModel rockets category S6. Four class comprises a category S6 — model rockets for flight duration with the tape. In my opinion, this category is captivating spectators and athletes entertainment. After all, the entire flight takes place, that is, on sight. These models and the competition for them is the best suited for beginners “missile”.

 
Championship class in categories S6 and boys, and adults one — Ѕ6А. Technical requirements for sports “projectile” as follows: the engine (pulse — no more than 2.5 NS) — one, length — not less than 500 mm, case diameter — 40 mm, the starting weight should not exceed 100 g, the maximum recorded time round — 3 minutes (180 points). The main detail (the original recovery system), which provides the greatest flight time, — the brake band, which for competition is not limited.
 
They are made of homogeneous, non-perforated material with a length to width ratio of at least 10:1. In flight, the tape must fully unfold. The athlete may, depending on weather conditions to use any tape.
 
I must admit that since the “birth” of that category (S6) all design, technological developments are carried out mainly with the brake band. Here the direction of these searches: select the size and material, thickness and styling methods. Starting conditions dictate the participants and selection of the brake band. So, for wind we need “hard” tape, to calm — “soft”. The degree of “hardness” determines the thickness of the source material film. From the first it varies from 0.015 to 0.025 mm, the second is about 0.01 mm.
I must admit that the FAI code does not limit the number of bands for the competition.
 
Ways of styling the brake band — a great many, the most common — “accordion”. It resembles the bellows of the Russian musical instrument. Step (width of the pleat) from 5 to 25 mm. Many athletes after folding of the tape is subjected to the forming (heat treatment). Folded tape is clamped into the fixture and allowed to stand in this state at 55° — 60°C. This treatment is the brake band increases its stiffness, it holds the “harmonica”. The best athletes for each flight in the new round uses a different tape, allowing time for “rest” used.
 
Fig. 1. Model missiles Ѕ6В of the champion of Russia 2002, L. Tarasova (Yugorsk)
 
Fig. 1. Model missiles Ѕ6В of the champion of Russia 2002, L. Tarasova (Moscow):
 
1—fairing; 2—connecting bushing; 3—bulkhead; 4—hinge; 5—the fastening thread of the brake band; 6—thread suspension frame; 7—brake band; 8 — body; 9—wad; 10—tail cone; 11—stabilizer; 12—end retainer MRD

 
A good confirmation of this are the brake band world Champions of 2006 among adults — the Polish athletes. Their sizes are: length — 1050 mm, width 97 mm, “accordion” — 4 — 5 mm, film thickness — 0.02 mm.
 
In the program of the world Championships starts model categories with tape (S6) was incorporated in 1978. It was the third world championship and the first to debut of Soviet athletes. The only medal — a bronze won then the author of these lines. Since then the winners, but not Champions was in the past years our athletes: Oleg Belous, Viktor Kuzmin, Yuri Firsov, Sergei Ilyin and Oleg Voronov. Held in 1997, the first world Careage — a kind of Olympics for aviation sports champion in the category (S6) was Nikolai Tsygankov.
Currently, the category model with the tape the most popular. It always involved the largest number of athletes. And this category is included in the program of all the stages of the world Cup.
 
Today the story is about models-Champions in the category (S6).
 
The proposed model missiles Ѕ6В (Fig. 1) developed by designer Alexander Tarasov (Yugorsk). This class of sports models with engines up to 5 NS for many years entitled “citizenship” at the Championships.
 
The hull is molded as a single unit on a single mandrel with the largest diameter of 39.9 mm. Thickness used fiberglass — 0.03 mm, the winding is in two layers. Before forming the annealed fiberglass and the mandrel is slightly warmed and smeared with mastic separation (“Edelvika”), In order to avoid air bubbles between layers when rolling still raw billet wrap tape tape width 10 — 12 mm and placed in a drying Cabinet with a temperature of 60 — 70°C.
 
Fig. 2. A model rocket Ѕ6В class champion, 2003 S. Romaniuk (G. Uray)
 
Fig. 2. A model rocket Ѕ6В class champion, 2003 S. Romaniuk (G. Uray):
 
1—fairing; 2 — connecting bushing; 3—bulkhead; 4—thread suspension of the case; 5—brake band; 6—housing; 7—wad; 8—tail cone; 9—stabilizer; 10—container MRD

 
After drying, the obtained resin harvesting process a file. Then cut ostrozatochennym cutter to the desired length.
 
Stabilizers cut from the treated and reinforced fiberglass balsa plate thickness of 0.6 mm. In the package (for 3 PCs) brought the contour to the desired shape and attach the butt to the motor compartment of the housing. One of the stabilizers, pre-wound threads with resin bonded retainer MRD — cut the wire, allied with a diameter of 0.8 mm with bent and exposed for the slice of the body by 6 — 7 mm end. Another stabilizer is attached to the thread of the suspension.
 
Fairing with a slightly rounded top (radius is 4.5 mm) were molded analogously to the case. Coupling sleeve — cut fiberglass tube with a length of 35 mm with an outside diameter of 39.9 mm glued one end to the lower part (skirt) of the fairing. At the other end of the sleeve glued to the balsa frame with loop, attached to a thread suspension. It is tied and the thread fastening the brake band.
 
Streamer (brake band) — sizes 1550×150 m — rigid Mylar film with a thickness of 0,024 — 0,03 mm.
 
The mass of the model without MRD and the brake band — 7.
 
Sport model rocket Kassa Ѕ6В (Fig. 2) champion of Russia S. Romaniuk (G. Uray) — representative of aircraft of the so-called “Ural” scheme, the author and developer of which is a team of rocketmodeler city of Chelyabinsk under the leadership of the deserved trainer of Russia V. I. Tarasov. The model is made according to fairly well-known technology.
 
Body — fiberglass tube of variable cross section and the maximum outer diameter of 40.3 mm, the minimum is 10.4 mm. the Material is fiberglass with a thickness of 0.03 mm in two layers and epoxy resin ED-6. After resin curing, the mandrel with the billet case is treated in a lathe (at 600 — 700 rpm) and cut to length — 405 mm. mandrel is Then carefully heated and removed from her willing body.
 
The same technology is molded fairing and connecting the sleeve to a length of 30 mm. glued It to the skirt of the cone to a depth of 5 mm, pre-abasiri its inner surface. The other (butt) end of the sleeve is closed with a balsa frame with a thickness of 1,5 mm, to which is glued a loop of strong thread. To it then tie the thread suspension package and system recovery.
The stabilizers are made of balsa plate with a thickness of 0.7 mm, the side surfaces of them are covered with glass fiber epoxy resin. To the body they are glued back to back. One stabilizer attach the Kevlar thread suspension.
 
Brake band (streamer) cut from printing Mylar film with a thickness of 0.025 mm, its dimensions — 1450×110 mm.
 
The mass of the model without the streamer and MRD -10 G.
 
Universal Polish athletes (Fig.Z). This will meet not often. I must say that in my memory this is the first time. Both champion in the same class (Ѕ6А) among boys and among adults the same team — Poland. But that’s not all. They — Michal Kumar and Leshik Malaga — student and coach. This creative community can only rejoice.
 
Yes, sports and their “shells” model missiles aroused great interest among the participants and specialists of the 16th world championship at Baikonur. At first glance, it seems nothing special. Conventional, traditional design. But it is a fact that, in my opinion, deserves attention. Moreover, this sports the projectile is “armed” Polish athletes in two categories — SA and Ѕ6А. And in the category of rotochutes (Ѕ9А) base (body) is made in a similar way.
 
One of the features of the model is a long enough tail cone part 148 mm. this can be seen as the desire of the designers a little bit easier to feed through the consumption of material for the hull and stabilizers. Another feature is the original solution ejection recovery system model from the case and a very unusual use of the wad. But more on that below.
 
Fig. 3. Universal model rocket class (Ѕ3А and Ѕ6А)
 
Fig. 3. Universal model rocket class (Ѕ3А and Ѕ6А):
 
1—fairing; 2 frames; 3—loop suspension; 4—connecting sleeve; 5—thread suspension rescue system; 6—recovery system (parachute or brake band); 7—housing; 8—tail cone; 9—stabilizer; 10—MRD

 
The case is made of two layers of fiberglass trehsutochny thickness on the mandrel of variable cross section, the maximum diameter of which is of 39.9 mm, the minimum is 10.2 mm. On this part of the mandrel is rolled cylindrical part of the motor compartment of the three layers. First one with carbon fabric, and then two layers of fiberglass. The aim is to improve the thermal stability of the rear of the hull. In the process of rolling is added to the resin and the pigment.
 
Giving polimerservice the resin, the mandrel with the wound preform is clamped in a lathe and the outer surface is treated, after which a sharp cutter cut to desired length — 425 mm, Then the mandrel is heated slightly and removed from her willing body.
 
This technology is molded and fairing with a length of 85 mm. Inside of fairing attach three balsa frame (for rigidity), and then glued the bottom ring of the connecting sleeve, carved from balsa, a width of 16 mm. Width of belt inserts — 4 mm. In the bottom frame fixed loop to connect the fairing to the housing by means of thread suspension.
 
Stabilizers (three of them) cut from a balsa veneer with a thickness of 1.1 mm, the lateral surface is reinforced with “glass”. To the body butt glue them. Along the line of attaching one of the stabilizers attach to the thread of the suspension. Brake band has dimensions: 1050х 97 mm, material: printing polyester with a thickness of 0.02 mm. Styling — accordion with a pitch of 4 to 5 mm.
 
Originally produced at the Polish missile wad. Unlike other athletes, this is not a trivial piece of cotton or foam cylinder, and a paper design. The basis of it — a tube of writing paper with a length of 265 mm and a diameter of 10.2 mm. At one end of it glued to the paper disc (blank — no holes), which “planted” cylinder length 30 mm. At a distance of 100 mm from the disc on the tube wearing one disk for stable positioning of the wad in the hull of the model.
 
The advantage of this design of the wad, obviously. Its weight is 1.5 g. It is not possible to descend the recovery system of the model and in the time of the launch, and in flight. Not thereby changing the position of the center of gravity of the model.
 
Preparing the model for flight takes place in this order. First top put the wad down to the appearance of the lower end of the stern section of the hull. Into the tube of the wad insert the upper part of the engine at a width of 2 — 3mm, fix it in the engine compartment. Then the top stack recovery system (brake band or a parachute), and attach the fairing.
 
In flight, after firing the lifting charge mrad, an energy pulse (blast wave) is transmitted through the tube (small diameter — 10.2 mm) and rests on the disc wad. He moves up and throws out of the housing recovery system. It can fly itself.
 
V. ROZHKOV

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