“ROGALLO” ASK THE SKY | MODEL CONSTRUCTION

Category sport model rockets with a soft wing (S10) is divided into four classes. The most common is the class Ѕ10А. Requirements for models are as follows: maximum total impulse MRD — 2,5 researcher, the starting mass of not less than 18 but not more than 60 g. the Maximum flight time in a round is 180 sec (3 min).

Competition for the duration of the flight of model rockets with a soft wing include the launching only single-stage models and their return to the ground in stable gliding flight, performed on the unit with a soft aerodynamic surfaces. The separation of the parts of the structure or the ejection of the spent casing of the engine is not allowed.

Aerodynamic surface creating a lifting force must be made of soft materials (cloth, paper, film, etc.). Details of frame models of this category (ribs, edges, etc.) can be made of any material.

To maintain the required flight path models category S10 you can use the remote control.

For the first time the rocket plane with a soft wing I saw in 1965 at the Moscow regional competition “the rocket”. Was then simplified the requirements for such models and was not dividing them into “soft” and “hard”. And those and others were one category — “raketoplana”. I must admit that the successful flights of raketoplana with a soft wing at the time was not yet.

And in 1967, also at the regional competitions, was presented already about a dozen models of raketoplana “soft” design. Moreover, different schemes like hang gliders and performed according to the scheme “duck”. But the basis and the other was the device proposed in the late 50-ies of Australian of Italian descent, Francis Rogallo in the construction of gliders. And today, all flying models with a soft covering only as “the wing of Rogallo” and do not call.

It is a similar model with soft wing, made by the scheme “duck”, let in 1968 to George Yakovlev to become a winner of all-Union competition of rocketmodeler-students in the class of raketoplana.

At first glance it may seem that “soft” rocket plane — a simple model. But the practice suggests otherwise. To make a model of this design to fly is not only good, but steadily — task with many unknowns. And only when in 1978 the competition in Czechoslovakia for the first time presented a similar raketoplana our athletes successfully made a speech — he won team and individual competition Yury Soldatov became the champion, and Oleg Belous took the second place, the interest appeared. Less than three months, and at the world Championships in Bulgaria, with “soft” raketoplana already played three teams.

With the introduction of models such as “wing, Rogallo” in a separate category (S10) major competition at them is not carried out. And tightening of additional technical requirements (the impossibility of separation of the elements) has complicated the work on such models. Because created earlier raketoplan was container. When we go to competitions, I’ve met models with “soft” wing, performed together with the body of the rocket. But to compete at a high level, these structures can not yet.

For those of rocketmodeler who are interested in rockets gliders with the “soft” wing and their construction taking into account the new requirements of the Rules of the competition, I want to note that today is the problem And its solution — “food” for the mind creative rocketmodeler-athletes. Hopefully, the experience of designing “soft” raketoplana container type will be useful in this case.

One of the first authors of the models with the “soft” wing (diagram of Rogallo) in our country is Oleg Belous — winner of many international competitions, European and world Champions in the class of raketoplana. Take a look at one of such models. Outwardly, it resembles a hang glider. Its fuselage is a pine rail with variable section (maximum 4×6 mm), to which the front thread with glue attach the notched spring (hinge), curved-steel wire with a diameter of 0.7 mm. To the two free ends tied to two rails with a section of 4×4 mm and a length of 580 mm, serving as the front edge of the wing. To the rear of Reiki of the fuselage glue a wad of lime. About the middle of the hinge is fixed the rack and the balancer with a length of 306 mm, and towards its free end adhered to the fairing.

Fig. 1. Model rocket glider wing, Rogallo Oleg Belous (Moscow oblast)

Fig. 1. Model rocket glider wing, Rogallo Oleg Belous (Moscow region):

1—container; 2—rack-fuselage (pine); 3—absorber; 4—thread-limiter; 5—rack-balancer (pine); 6—elastic return; 7—loop (thread); 8—fairing; 9—thread determinization; 10—tail wad; 11 —spring hinge (OVS Ø 0.7 mm); 12—thread-angle stop sweep; 13—edges (pine); 14—stabilizer; 15—wad (wool with talc); 16—mrad.

The dotted line shows a pattern of the workpiece film stitched.

Rail-rocker in the desired position is fixed with a thread, one end of which is pivotally fixed to the fuselage (at the front). The deviation of the rod of the balancer takes place by means of elastic return, mounted on the rail of the fuselage (in the rear).

Rocket hang Mylar film with a thickness of 0.01 mm. weight of the model approximately 15 g of a Carrier (container) formed of two layers of glass, of a thickness of 0.08 mm with epoxy resin. Once hardened, the resin housing is treated with sandpaper and cut to desired length — 775 mm. In the rear attached three stabilizer made of balsa plate with a thickness of 2 mm.

Debugging models with raketoplana “wing, Rogallo” many unknowns, so focus on it in detail.

When balancing the model to achieve that the center of gravity was located at the seat of the hinge Assembly. To achieve this we need to download or head part (attach some lead to the rail), or the rear wad. After that, launch the model with your hand a few times, and the first launches are doing smoothly. If the rocket is good (stable) plans, you can throw it up when folded. Right ambulancewoman the rocket plane will always turn in planning provision (rail-saw to the fairing and down).

Very often, when the disclosure of “soft” wing rocket plane goes into a dive. There are several reasons. The first is a large the rate at which the unraveling of the wing. In this case, it is necessary to increase the deceleration MRD or add the wads.

The second reason is the center of gravity of the airframe is close to the nose (the so-called forward center of gravity). You can move the small tilt back Reiki balance bar, strengthening the thread-lock, or a download of the wad tail.

The third reason is the model is small (insufficient) directional stability. You can increase the angle of the V, bent a little upwards the ends of the springs or increase the windage. But you have to change the cording.

There are two ways of preparing the model to run.

The first rocket plane are placed in a container without an engine, which is inserted in the opening area.

But the most common second option. At the beginning of the container is fixed mrad, then placed wads of cotton wool with baby powder with talc. Further, the front edge of the rocket stack to the fuselage, rack and balancer bends forward and carefully wrapped all the stacked slats “soft” wing. The folded rocket stacked in the container. On the head fairing along the annular grooves tie a string with a wick that holds the string-retainer.

In flight, once the wick burns through the thread in the annular groove, released the string-retainer — rod-balancer under the action of elastic return is rejected back. The model switches to kupirovaniya — worked simplest automatic forced landing.

V. ROZHKOV

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