SUPERPOLITIK JUNIORS

Categories World of models

SUPERPOLITIK JUNIORSAttempts to use the competitions to openly simplified educational technology in the classroom cord aerobatic models, naturally, can not give good results even when well developed the skills of the pilot. But, oddly enough, is equally deplorable results brings and following the design methods of adult artists. The explanation is simple: the boys, even a few years dedicated solely to piloting, may not be so rich operating experience of the championship-tion equipment and motors which are required when you use a specially designed professional “pilotage”. But the latter, as a rule, is, in fact, the epitome of achievement in this sport классе1 And any drawings of modern models-“Champions” (which become the base for the construction of even the Junior vehicles with engines of large cubic capacity) absolutely exclude any discounts on “ignorance” or “inability”.

One solution is to give juniors, who gained a certain experience in the pilot class, a special technique that has, so to speak, “intermediate” characteristics. A basic set of requirements — a sufficient degree of stability for increased maneuverability; ultra-reliable as the model and its behavior in the air, and (almost first) easy operation, reliable powerful engine.
 
One of the solutions to the problems we are about to submit today to the readers. Because the publication is not intended for novice modelers can not dwell on the intricacies of technology manufacturing pilotage — at the heart of its design is well known in the modeling techniques. But on what principles are laid down in the scheme offer machines, I think that would be helpful to know everything.
 
The main question is the optimal combination of stability and maneuverability. In this case, the requirements of the compromise satisfy both developed relative shoulder stabilizer with a relatively narrow wing and use of a control scheme with flaps. Immediately it should be noted that the all-moving tail — not a tribute to the race for super-maneuverability! Although among the many athletes there is a perception of increased efficiency of such a stabilizer and its associated signs of instability, in our case it is not.
All-moving tail on pilotage solves two tasks simultaneously: a sharp decline in the weight of the tail of the model (which is the reduction of the moment of inertia about the axis of the turning maneuver) and elimination efforts in the drive system of a wheel (stabilizer fully compensated on the hinge moments and loads on the control system are only from the drive flap).
 
As you may have noticed on the model flaps installed only in megalocnus the area of the wing. And it is justified. After all, if we carefully look into the experience with a variety of flight vehicles, it becomes clear that the main function of flaps — not in creating the high lift force on the wing. In favor of this statement says to compare similar machines with different specific load; reducing it as much as it will increase wing lift, the use of flaps, you will never get an equally significant increase in maneuverability. Therefore, the purpose of the flaps is the formation of a taper of the flow behind the wing in the maneuver required for a good stabilizer. Of course, the original role of the flap as a control, the lifting force remains, but, we repeat, is secondary.
 
Another factor taken into consideration when designing the new model— the flexibility of the wing vertically with sufficient rigidity on twisting. About the need for such a wing I know not all, so “D^ it is useful to emphasize once again going into” nie sharp improvement in performance of the maneuvers associated with ‘elastic’ planes.
 
Fig. 1. Main dimensions of the pilot models
 
Fig. 1. Main dimensions of the pilot models.
 
Fig. 2. The fuselage
 
Fig. 2. Fuselage:
 
I — spinner, 2 bow frame (plywood 1.5 mm), 3 — beam engine mounts (birch section !0X 15 mm), 4 — engine KMD-2,5-ass B her wall from the “Rhythm”, 5 trim motor (plywood, 1.5 mm), 6 — prosperous (plywood, 1.5 mm), 7 — parts polycarbonate and the wall of the cabin (ele-e- crockerton), 8 — light (plexiglass thickness 0,8—1 mm; back shaded with Bor-Ter of the fuselage), 9 — tail insert (Linden or birch; the screw that secures the rear edge 7 of the wing to glue in the finished fuselage), 10 — Central / rib detachable hood (lip thickness of 3 mm), 11 — power frame (switching of the four layer-/\ EV plywood 1.5 mm), 12 — fuel tank size 30X45X50 mm, a volume of 67 cm3 (tin tin, / ‘^SjB tube drainage and nutrition — brass tube ….. 0. 3X0. 5 mm), 13 — detachable hood (lime hollow from two symmetric blanks 27Х60Х X 190 mm), !4 — bolts MZ engine mounts (to glue on the epoxy impregnated wood in billets bars engine mounts). Below shows a simplified version of the contour of the fuselage (lime plate thickness of 10 mm, sheathed after processing the outline of the fuselage on both sides with plywood to a thickness of I-1.5 mm; bed wing — plywood 1.5 mm, with a transverse direction of the fibers of the shirt, front fairing reinforced fake; an imitation of light — Plexiglas with a thickness of about 3 mm).
 

 
Fig. 3. Wing
 
Fig. 3. Wing:
1 — flexible wires findings of the control, 2 bezels for the-an ending (Linden, 2X4 mm before gluing to steam), 3 — the outline of the ending (plywood, 1.5 mm), 4 — falcinellus (Linden, 3 mm), 5 — endbox-wall of the spar, (lime, 3 mm), 6 — the leading edge (Linden or pine, 10X 15 mm; to facilitate the gouging to a thickness of about 4 mm), 7 — power forehead (lnpa or pine, 3…4H30 mm) 8 — rib (plywood, 1.5 mm, or symmetrical upper and lower arches of lime with a thickness of 3 mm), 9 — rocker, and a 10 — solitaire for mounting wooden (plywood, 3 mm), 11 — Central wall of the side member (plywood, 1.5 mm), 12 — pin fixation of the wing to the fuselage (aluminum, 0 to 5 mm), 13 — podstrekava boss (Linden), 14 — covering the Central section (plywood, 1… 1.5 mm), 15 — posterior boss (Linden), 16 — solitaire front socket fixing beams (Linden), 17 — a weight of 15 g, 18 — oblique rib (lip, 2 mm), 19 — trailing edge (Asia, ЗХ5 mm) 20 — borders the rear edge (pine or basswood, 2-5 mm), 21 — hinge hinge of the flap, 22 — plate rear fixing beam socket (Linden), 23 double — sided strengthening of the edge (pine, 2X5 mm), 24 additional edge (pine, SX 5 mm), 25 — wing flaps (foam thickness of 5 mm, a banded fake strips and covered with paper or lightweight frame with a shell made of cardboard), a 26 — tripod mount of a hog.
 

 
 
R and p. 4. Section of wing
 
R and S. 4. Cross-section of the wing:
A — the basic version of the power circuit (item numbers correspond to parts in figure 3; rib in the second, a lightweight version of lime), B — variant with “Boytsov” a forehead from lightweight foam, reinforced of pine shelves of the spar and lined paper on the glue (ribs cut from a foam thickness of 3 mm, a banded rails 2X5 mm; the joints with the flanges of the spar are reinforced with plywood gussets).
 

 
 
Fig. 5. Beam
 
Fig. 5. Beam:
1 — the front screw of the MOH mounting beam on the wing 2 — front end (lip thickness of 7 mm), 3 — cradle (lime thickness 10 mm) 4 — wall (insulation thickness 0.6 mm), 5 — rear M4 screw mounts of the beam (before you trim the sides to mount the frame beam with pre-taped the threads with epoxy glue power frame), 6 — power frame (plywood, 4 mm), 7 — stringer (pine, 2,5X2,5 mm), 8, 11 — frames (foam PVC 2 mm thick), 9 — jumper (lime, 2.5 mm), 10 — lower valance (on cardboard or thin plywood), 12 — boss (Linden, 5 mm), 13 — outline of the keel (aluminum knitting needle 0 to 3 mm, the ends of the wire before gluing the wooden parts to degrease and wrap a thin thread), a 14 — rib keel (pine, 2X6 mm), 15—sheathing of the keel (Mylar film), !6 — top stringer (pine, 3X5 mm). In a simplified embodiment, a beam made of plates of lime with a thickness of 7 mm. the tail thickness of the workpiece is reduced to 4 mm, in the areas of installation of the rear mounting screw M4 and in the place of attachment of the stabilizer beam on both sides sheathed against cracking thin plywood.
 

 
 
R and p. 6. Stabilizer
 
R and S. 6. Stabilizer:
1 — rounding (Linden, 6 mm), 2 — over-end (Linden, 3X6 mm), 3 — screw MH as the axis of rotation of stabilizer (glue in the boss), 4 — boss (Linden), 5 — power part of the edge (pine, 2X7 mm), 6 — insert edge (pine, 2X3 mm), 7 — rib (pine, 2 x2 mm), 8 — a wall edge (pine, 1X4 mm), 9 — rear flange (pine or basswood, 1,5X6 mm), 10 — washer with self-locking nut MZ. Horn mount on the left boss.

 
Fig. 7. The diagram of the control system model
 
Fig. 7. Diagram of the system management model:
1 — rocking chair (made of anodized aluminum with a thickness of 2 mm), 2 — draught flap (steel wire 0 2.5 mm), 3 — flap 4 — the axis of rotation of the flap, 5 — horn of the flap (brass thickness 1.5 mm), 6 — pull rudder (aluminum knitting needle 0 2.5 mm), 7 — hog steering (brass 1.5 mm thickness), 8 — the Elevator (all-moving stabilizer), 9 — axle steering, 10 — control cable.

 
The proposed pilotage certainly not problemchen. There is no need to look for some complicated ways, as too easy a device is not only sensitive to wind, but is poorly managed in some situations due to inaccurate passing signals from the control stick to the rudder (although part of the problem is removed by application of compensated suspension all-moving stabilizer). What really deserves attention from the point of view of saving every ounce of weight — so it’s the tail part of the model mainly determines the moment of inertia of the whole model.
 
And lastly, about the engine. Without a good motor to pitch in drinking-also not worth it; therefore, initially believe that you have a KMD enumerated with tight controls. The motor in the aerobatic mode as running in any condition would improve if you’ll be able to find the back of the spool wall from the old “Rhythm” and attornevs Carter KMD rear by about 2.5 mm, then install it instead of regular. Major modifications of the engine it is necessary to mention the following: the deviation of the axis of the cylinder back to prevent slippage of the connecting rod with crank pin (due to podgotovki top mounting end of the crankcase with the appropriate plywood screw fixing the sleeve in the head); the recess mallodonitae slit in the lower end of connecting rod by cutting “pockets” at its ends; the improvement “rimovska” spool (better and easier to make a new one from steel SOHGS wall thickness distribution in cylindrical zone about 0.5 mm). Timing adjust is not necessary; in the manufacture of the new valve, you can take the intake phase equal to 180°, with a pass to NMT 30°. A large shift of the phase of the intake is not needed, since the motor is calculated on the average speed. But, of course, in any case, the improvements makes sense only if you have a good, “tight” pair piston — cylinder. Acceptable as the means of restoration of compression not to chrome-plate the sleeve (it’s complicated as according to the method of applying chromium, and technology adaptation) and a piston are examples of such improvements already exist and give good results. Propeller for modified engine KMD is made of wood size 220ХЮ0 mm (step — up to 130 mm, depending on the status and mode of operation of the motor). The ratio of the deflection angles of the flap and rudder can be chosen in accordance with the experience of the pilot and personal wishes. Alignment of flight — about 20-25% of the SEA wing (without flaps).
 
V. KIBETS

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