DESK OF SPEED SPECIALIST

PARTA OF SPEED SPECIALIST“Wow, beautiful…” — that was the unanimous opinion of the participants about our high-speed cord models. After a short discussion, the boys made a “sentence” is a set of custom-making seem stamped out of plastic: “if we are…” oke We tried to explain that such models can build one that sets parcels elega/^tion speed is irrelevant and that make it much easier than any other… in Short, it ended up that I had to give details about the design, technology, construction and finishing of the new device. And then started flying again confirmed the unwritten law of aviation — a beautiful machine fly well!

So how can you make this model? What you need to do? We want to share today with the young followers of the aeromodelling sport.
 
First of all about the materials. All the details of the high-speed glider cord sawed from plywood. “Graph paper”? It will need a very small cut; basically a model made of plywood with thickness of 3 to 5 mm!
The result is a very durable design. On a championship speed repeatedly practiced by novice pilots, and thus no damage! Concerns that the model in this embodiment will peretyagina, were in vain. Glider microplane weighs only 150 g, after the installation of the engine with a propeller, a fuel tank and system management in the amount of takeoff weight from 360 to 400 g in different versions. A relatively small load on the supporting plane and causes easy control as on the rise, and in the passage of the “base”, and the excellent behavior of the speed under any weather conditions. And this is an indispensable requirement to the apparatus controlled is still not enough experienced athletes.
 
Fig. 1. Speed control line training model of the aircraft
 
Fig. 1. Speed control line training model of the aircraft:
 
1 — motor, 2 — wing, 3 — fuel tank. 4 — pull rudder, 5 — body, 6 — the stabilizer. 7 — handlebar height. 8 — wing 9 — point fixing of the sending node.

 
WING cut of three-millimeter plywood. After precision machining the elliptical path of the leading edge of the workpiece with a compass (it is used as rasmas) bounces a strip width of 10 mm and the rear about 20 mm. Then use the planer the wood is removed from these lines to half the thickness of the plywood to the edge. Finally PLANO-convex wing profile brought skins of different grits glued on a trim of thick plywood. Along the rear edge of the bottom layer of plywood should remain almost intact, the rest clearly visible glue joints only help to achieve high accuracy of machining profile. In the Central part of the wing you can leave the area with parallel lines section. Controlled by the lack of twist in the plane (of course, it procurement needs to be completely smooth), you can go to work on the next parts.
 
STABILIZER by material and processing methods completely analogous to the wing, the only difference is the profile on the horizontal tail it is symmetrical. The Elevator is cut from the stabilizer only after viskazivaniya surface.
 
The FUSELAGE is going to epoxy glue the three plates five millimeter plywood. The Central layer is directly by the fuselage, the two side plates increase the mounting area of the engine and tie the engine to the wing. Better yet before gluing to finish the processing of the edges of the lining — subsequently, this will be much more difficult. When there will be a total rejection of tar in the nose of the fuselage is cut a window under the engine, marked, drilled and cut through holes for the fastening screws of the motor. Video horizontal generatrix of the fuselage allows you to accurately lay out not only the window under Carter, but under the wing and stabilizer. After adjustment, all grooves on the resin are screwed four screws M3 flat-head and front part of the fuselage on the left is sheathed millimeter plywood. Work on the fuselage ends with a recess slit for mounting the control arms of and the set of lugs that covers the “engine compartment” in front.
 
R and p. 2. The fuselage
R and S. 2. Fuselage:
 
1 — center brace, 2, 4 — pads. 3 — the lining Board, 5 — bolt engine, 6 — bow boss, 7 — point fixing tank.

 
The CONTROL SYSTEM of a conventional circuit well-known to even novice cordovil. The only that openings through which pass the curved end of a rod of the steering wheel and carabiners, cord, reinforced by means of setting of clips from pieces stainless steel tubes. As shown, these swivels are absolutely not developed even when flying on a dusty kartodromo. Pylon rudder prikladyvaya only after the exterior of the stabilizer and linkage steering, the rocking chair is installed on the trimmed fuselage on the M3 screw. You need to pay attention to the threaded part of this “axis” would not have on the Central hinge rocking. Snap hooks after the connection of the ends of the cord are looped lengths of plastic tubing.
Interestingly solved the smart host for cords, placed on the left wing. Even before the sealing of the ends of the steel “strings” on them to put on thin cuts of the springs from the shaft of the device or the cable for the camera, and on top of a short stretch of rubber tubing tightly subsequently included in the aluminum bracket on the console. In this embodiment, it is possible to get rid of conventional control cables and carabiners, creating additional aerodynamic drag.
 
POWER SYSTEM the engine is pressure bleed from the crankcase cavity. Tank, simultaneously performing the functions of a fairing of a plant, soldered tin-plated tin thickness 0.2—0.3 mm., Its volume enables engine operation, a time quite sufficient for a confident pass “base”. The tank “hung” on the fuselage using the M3 screw (don’t forget to solder it into the wall of the tank even when it was manufactured, the mounting on the outside is completely unacceptable!). Between the tank and the side of the fuselage installed a strip of foam rubber with a thickness of 2 mm., Even after seemingly complete compression of this elastic element significantly increases the reliability of the engine by reducing vibration of the tank and foaming. Tube selection pressure sticker in the rear wall of the engine under her left rib, in the cavity of the crankcase it has to go under the cheek of the spool.
 
Fig. 3. Fuel tank
 
Fig. 3. Fuel tank:
 
1 — side panel 2 — base, 3 — front wall 4 — pipe power engine, 5 — tube for supplying pressure to the pressurization tank 6 — M3 screw mounting of the tank.

 
Fig. 4. Control system
 
Fig. 4. Control system:
 
1 aluminum rivet Ø 2 mm, 2 — strip (made of anodized aluminum 1 mm thick), 3 — hog steering (dural profile-area), 4 — plastic tube fixing end of the pull rod in the pylon with a length of 8 mm, 5 — deadlifts (OVS wire Ø 2 mm). 6 — rocking chair (made of anodized aluminum with a thickness of 2 mm). 7 — carbine (wire OVS Ø 0.8 mm).

 
Fig. 5. Smart host for Nord and its mount on the wing
 
Fig. 5. Smart host for Nord and its mount on the wing:
 
1 — wing (left console), 2 aluminum rivet Ø 2 mm, 3 — bracket (aluminum profile corner), 4 — the crutch (the wire OVS Ø 1,8 mm), 5 — thin spring with a segment of rubber tubing.
In the hole at the end of the crutch may be fitted supporting a wheel of the chassis when the bike scheme.

 
EXTERNAL FINISH of the model is probably the most interesting in the proposed Expressway. The fact that to achieve excellent quality results without visibly loading apparatus managed by conventional Mylar film! Any, the most intricate lines of colors, the most complex paint schemes are now performed high in one night. The main thing is to only use glue “Moment” applied to the wooden surface and thoroughly dry, and hot iron. The heating temperature of the soles of his feet need to pick up experimentally, so that the tape is securely glued, and bubbles under it arose.
 
So off individual elements of the construction of the model (wing, stabilizer, Elevator and aft fuselage), and then the film is cut from the butt sections and high-speed going to epoxy glue. At the seams the resin forms a smooth “fillet” (the excess removed a pin head), not only increases the reliability of connections, but also protects the film from the separation in the joints of the parts. Around the circuit, of course, the Dacron should be tucked, forming a kind of lap-lock. When multi-element sheathing, it is useful to cover the entire surface of the model a light coat of varnish parquet. It will not peel off from the substrate and the thin lines of the strips of film.
Finishing and painting the forward fuselage — normal. In addition to simplicity, this finish will provide the notched part and greater reliability to protect the structure from the impregnation with fuel.
 
The CHASSIS is intentionally not shown in the drawings. The fact that he tested various arrangements of wheels and racks, and they all gave satisfactory results at take-off and landing characteristics. Therefore, the chassis can be constructed to your liking. This can be a simple wire clip, normal wheeled chassis with a rack out of sheet aluminum or wire. The massive nose section of the fuselage allows you to mount any of them. For beginners we can recommend the two-wheeled option with racks of wire, installed on the wing. This scheme will provide the easiest and most reliable takeoff. Strength same telefonerna wing enough to withstand the impact from the stands at the rough landing. Tail skid from wire Ø 1.8 mm privertyvaetsja to the fuselage with one screw M2,5 and the junction of poured epoxy.
 
ROTOR GROUP deserves special discussion. High-speed built under KMD-2,5 and under the modern “Rhythm”. B the first embodiment, the modifications undergone only the propeller, the engine in the upper left of the tripod mount of the rear wall is mounted a fitting selection pressure sverlova inclined holes Ø 1 mm, extends under the cylinder liner.
 
Those who want to achieve high results with the “Rhythm” of the modern sample, will have to thoroughly work with this engine. The first thing to take away Carter without cracking legs and a good tight fit of the bearings of the crankshaft. If the fit loose, like on most engines “Rhythm”, we can recommend sealing the indigenous ball-resin mixed with aluminum powder. The timing greatly expanded by replacing the connecting rod shorter (and more reliable) “meteorology” and install the ring under the bottom end of the sleeve (you can use the compression ring from the piston engine “Comet”). Overlay threaded carb removed, the entrance hole in the rear wall zaproponowano, set the nozzle from the motor REGION or CSTOM. Using the files section of the window in the valve is significantly extended, fixed the benches in the intake tract are eliminated, ashleeee characteristic of series motors, overlap almost two-thirds of the lumen of the flow section of the carb that failed distribution window of the spool even at its largest opening.
 
R and p. 6. The installation of a single blade of the propeller on the engine
 
R and S. 6. The installation of a single blade of the propeller on the engine:
 
1 — Kok (hardened aluminum), 2 — blade propeller, 3 — counterweight (steel hardened, normalized), 4 — bearing bushing.

 
Fig. 7. Calculate the area of wing formed by the right quarter-ellipses.
 
Fig. 7. Calculate the area of wing formed by the right quarter-ellipses.
 
The result of this work, mssh,the thrust of the engine increased significantly. Increased heat load that is demanded to improve the cooling of the cylinder (forced “Rhythms” were prone to “zadavlivanii” at the slightest overload). Careful analysis showed that the gap between the sleeve and the cooling jacket is unacceptable high, because of this so often encountered and primary of kontrpartiya to the mirror of the cylinder. Pick parts with desired landing failed even after bulkheads dozen motors. Reduce the same thermal resistance, we have achieved due to the introduction of aluminum strip. Taken from the engine casing neatly wrapped with foil (the gap between the edges of the tape about 1 mm, the combination is unacceptable, even with a double-layer winding) and quickly injected into the heated to 130-150°, greased shirt.
 
In any case, the engine worked with single-vane propellers, modified from serial plastic, 200X200 mm. To “Rhythm”, which develops maximum power at relatively low rpm, it is enough to shorten the blade to a radius of 90 mm without changing its geometry, KMD-2,5 work better with lightweight propellers. In addition to reducing the width of the blade, a significant amount of material removed and the top side of the screw, the profile is thinner. The balancer runs only from steel having a strength of at least 100 kg/mm2, the replacement of other materials and less durable steels is strictly prohibited! In the drawings, the sizes of the workpiece; more accurately they are selected after checking the balance of the propeller. After the balancing operation, it is necessary to perform another operation. It’s… again, it would seem to unbalance the finished screw! The radius of the blade decreases by 0.5—0.7 mm at its very end. This is necessary in order to provide the perfect balance in the output of the engine at maximum rpm. The fact that the nylon screws unlike wood and fiberglass have considerable elongation from centrifugal loads, a preliminary shortening of the blade allows to compensate the influence of the elasticity of the material.
 
R and p. 8. Scheme revision serial nylon propeller 200X200 mm for engine KMD-2,5.
 
R and p. 8. Scheme revision serial nylon propeller 200X200 mm for engine KMD-2,5.
 
Fig. 9. Hinge rudder hinge (2 pieces)
 
Fig. 9. Hinge rudder hinge (2 pieces):
 
1 — loop (semi-rigid wire Ø 0,8 mm, straightened paper clip). 2 — wrapping with cotton thread. Joints which are stuck in the holes at the ends of the Elevator and stabilizer to the epoxy resin.

 
The final step is determine whether to install keel. This element is deliberately not made in advance due to selection of its mass is easy to shift the center of gravity of the entire model to the desired position. Alignment speed should be within 10-15 mm from the front edge of the ventral section of the wing.
 
Before the first flight check again the lack of twists and loose all removable items. At takeoff speed behaves perfectly. Here a positive effect of its asymmetry, the center of gravity of the device in scope is exactly on the axis of the fuselage, the large separation of centre of area and centre of gravity provides a reliable stretch cords even at low speeds.
B. SOLOVIEV, candidate of master of sports

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