“HUMMINGBIRD” FROM CALIFORNIA

Held in the fall of 1991, sports bilateral meeting of American and Soviet missile-modelers winner in the class S4B was Robert Park, a native of the state of California. His rocket plane “Hummingbird” for all the apparent simplicity has a number of original technical solutions. One of them is separating the propulsion unit. Second — change the camber of the wing by the deflection of the flaps.

Structurally, the model consists of a rocket airframe and propulsion unit. The airframe is made by the classical scheme. The basic material for the manufacture of balsa.
 
The fuselage, stacked, glued two balsa plates (upper and lower) with a thickness of 1.2 mm and two balsa sides with a thickness of 1 mm. the Internal cavity of the forward fuselage on the sides strengthened with plywood linings. The top plate is made two cuts: one at a distance of 45 mm from the front edge (to drive the pusher), the other at a distance of 155 mm (for drive bracket flap). The pusher is made of slats with a cross section of 3X4 mm and a length of 100 mm It moves between the plywood lining the sides under the action of the actuator, mounted on the engine block.
In the rear fuselage, glued the stabilizer and fin are carved from balsa plates with thickness of 1.2 mm. Stabilizer is mounted below the fuselage, and the keel on the starboard side.
 
Model rocket R. parks (USA)
 
 
Model rocket R. parks (USA)
Model rocket R. parks (USA):
1 – the fairing 2— guide tube, 3— body, 4— container, 5— blank, 6— pin (holder) mrad and 7 mrad. 8— pole, 9— lower panel of the fuselage, wing 10, 11 flap, 12— bracket, flap, 13— elastic return, the 14— sidewall of the fuselage, the 15— Kiel, 16— upper fuselage panel, 17— the pusher 18— stabilizer, 19— clip MRD, 20— connection thread 21 — the lever of a drive of the follower 22 a spring, 23— pin, 24— brake band, 25—strip boards 26— brake flap in the folded position.

 
The outer surface of the fuselage and tail are covered with long-fibre paper (“Japanese”) and covered with nitrocellulose lacquer. To the left side front is attached to the brake shield. The role of the hinge performs a leaf spring of thin strips of aluminum.
 
The wing is made from balsa. The greatest profile thickness of 4.5 mm. at First the pattern is cut from sheet balsa two symmetrical halves which are then treated with the contour and profile. The surface of the wing hang long-fibre paper, sand and coated with nitrocellulose lacquer. Then cut off the flaps and is pivotally hung them on consoles, sticking to the lower surface of the wing with a strip of masking tape 20 mm wide. At the root edge flap mounted celluloid brackets drive system. Console glued together under the angle of the V is 160°.
 
The finished wing mounted on the top panel of the fuselage so that the brackets of flaps joined to the corresponding panel cutouts. After that you can attach rubber bands return that hold the flaps in a slightly deflected down position (making the wing profile becomes convex-concave).
The motor unit includes a housing and a container. The case is made of thick paper and has a length of 175 mm. is spiral Wrapped on the mandrel with a diameter of 13.5 mm. installed Front fairing from balsa and rear fixed sleeve length 63 mm with a recess for the brake band. With the opposite from the recess side glued blank, in the face of which is pressed a steel pin with a diameter of 1.5 mm.
 
The container (tube length 105 mm) is molded from fiberglass. One end is made a longitudinal cut with a width of 5 mm and a length of 45 mm. To the other over the neck glued to the pylon. Here is the same, but on the other side of the container, glued the retainer MRD, bent from a steel wire of 0.5 mm. 0 Pilon profiled balsa plate thickness 7 mm. In pylon mounted a spring and a notched lever pusher carved from basswood.
 
The housing and the container are connected by a strong thread length of 300 mm. In place of its attachment on the housing is glued and thread recovery system (the brake band). The guide tubes two. Their length of 15 mm and a diameter of 4.5 mm. they are Located on top, one for the body and container.
 
The launch mass of the rocket is about 30 g, and the actual planning part — 10 Model off the engine “Delta” of the Czech and Slovak designer and Modeler I. Taborskeho.
 
Preparation of the rocket for launch is as follows. In the container insert of MRD and fixed with the holder. In the recess of the sleeve body placed in a rolled tube and the brake band is worn on the sleeve of the container, thus connecting the housing with the container. The drive lever is inserted into the front cutout of the top panel of the fuselage. In the final phase of this operation, the pin lock is inserted into a corresponding hole of the forward fuselage. The pin serves as a castle that protects from the impacting force of the ejector spring.
 
Drive in the moment of connection of the parts of the model begins to push on the pushrod, which, in turn, transmits the force on the flap brackets, and they are slightly deflected upwards. Thus on takeoff the curvature of the airfoil decreases.
 
The brake plate is pressed against the side of the fuselage and tied off with thread. Then set the fuse time limit of planning. The placement of the wick in order to avoid burnout of the fuselage paste over a strip of foil.
 
After the launch and burnout of the fuel is triggered expelling charge mrad. Almost simultaneously (delay not recorded visually) occurs as the separation of body and container, and the ejection of the entire propulsion unit elasticity of an ejector spring. At the same time the flaps of the glider under the action of elastic bands are deflected to the lower position. The curvature of the airfoil increases, which is necessary for improvement of gliding properties of the model (compared to “flat” wing descending from the same height, much more). The glider continues to fly, and the motor unit disassembled lands on the brake band.
 
In the final phase of the flight triggers a forced landing: the wick burns through the locking thread, and the brake flap is deflected to the side. Model the result becomes unstable in the spiral mode of descent and safely, without damage lands.
 
V. ROZHKOV

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