IN lately small models of gliders made from EPP began to appear in toy stores, in other words, from ceiling tiles. Of course, such a toy flies beautifully, can withstand many flights and can be used anywhere, but the prices are steep - $9 apiece. But you can also make a homemade model by spending no more than 30 rubles on an airplane! So, let's start sculpting our toy.
Materials:
*ceiling tiles without relief pattern
*PVA glue
*pine slats 4x4 mm
*buttons
*clothes pegs
*pins or needles
*pens, markers, etc.
*stationery knife
*fine skin on a block
*plasticine
First you need to print and cut out the templates for the airplane.
It is advisable to glue the printout to cardboard. Then attach them to the tile, secure with buttons and draw the wing, stabilizer and keel.
Afterwards, we remove the templates and cut out the workpiece with a stationery knife (or a medical scalpel) with an allowance of 1-2 mm.
Be careful not to touch the workpiece lines.
Now you need to process the workpieces. We mark the boundary lines, take a block with sandpaper and give a profile to the wing and stabilizers using back and forth movements.
You need to process it confidently, smoothly, without jerking, otherwise you can ruin the part. Of course, you can give a profile with a heated iron, but this method does not always work.
If you have given details the required form, then you can start gluing. Never grab the Moment glue! Solvents will turn the plane into mush, so you need to use PVA glue. A rail 18-25 cm long is smeared with glue on one side and the other, and left for 5 minutes so that the glue is absorbed into the wood. The middle of the stabilizer and wing is marked and the bottom is coated with glue along midline. Next, we secure everything with clothespins, the keel is attached with pins to the wing also along the midline.
In our age of computers, the Internet, home robots and mobile gadgets, traditional modeling is not as popular as it was 20-30 years ago. But it’s unlikely that anything can compare with the feeling when a model assembled with your own hands from scrap materials successfully floats/rides/flies. In this article we will look at making a simple paper glider.
Such a glider is made only from scrap materials and requires no more than an hour to manufacture (see figure below). The hardest part is the adjustment. But if everything is done according to our recommendations, the model will fly well. Increasing the size of the wing in span and chord will not affect the strength at all. Therefore, the size of the model can be safely increased by one and a half, even twice. It has one more feature that characterizes its aerodynamic qualities. Pay attention to the wing profile. Its unusually large concavity increases lift. That is why, with a given size and weight of approximately 60 g, its flight performance is twice as good as that of a sports model of the same class. Launched using a 30-40 m long rope, the glider will remain in flight for more than a hundred seconds.
The glider model is collapsible. It consists of three parts: the wing, stabilizer and fuselage. This makes it more convenient to store and transport it in a paper or plastic bag.
Now get acquainted with the manufacturing technology. Place a sheet of Whatman paper on the table. Draw on it in life size contours of stabilizer 1 and wing 5 according to the dimensions shown in the figure. Don't forget to give allowances for step 1 folds. Then use sharp scissors to cut out the blanks. Be careful not to accidentally wrinkle them. To give the wing the necessary curvature, the workpieces should be pulled with force over the edge of the table. It's done like this. Place the workpiece on the table so that the leading edge is parallel to its edge. With your left hand, press it lightly against the table top, and with your right hand, pull it down, causing the paper to bend against the edge. Repeat this operation several times, gradually increasing the bending angle. Then outside With the tip of the scissors, lightly press the fold line onto the stabilizer and wing blanks. The wing and stabilizer are ready.
Next, cut out two paper blanks for rib 6 and one for rib 7. Shape them as shown in the picture. Lubricate them office glue or PVA glue and glue it to the wing. Adhesive connection The parts will be more durable if the gluing points around the entire perimeter are also pinned. We do not recommend permanently gluing ribs 6 if the central part of the wing is skewed. When gluing rib 7, pay attention to the lower plane of the wing - it should be perfectly flat. To prevent warping of the workpieces, insert pins only from the top after gluing. After gluing the ribs, immediately place the wing with its lower surface on the table. The wingtips should be made without bending the paper. Otherwise, they will not be strong, and then they will need to be further reinforced with paper gaskets. Stabilizer 1 is assembled from two blanks, having previously bent the edge of one of them, as shown in the figure. Glue the leading edge of the folded edge and press it with a small weight.
The fuselage is made from one wooden slats with a cross section of 8X8 mm square or round. The ends should be cut into a cone with a sharp knife. The finished fuselage must be cleaned with sandpaper. The stabilizer and wing mounted on the fuselage should not rotate. To prevent this from happening, the paper tubes should be twisted and glued onto a square piece. Best material for tubes - thin notebook paper. Previously, paper blanks 2 and 8 are molded by rolling them tightly at the ends of the rail. Then twist the tube with your fingers, turn it 2-3 turns and, after lubricating it with glue, screw it again. Wrap the workpiece with thread or rubber band until the glue dries completely. Then use sandpaper to clean the edges that are hard from the glue. The finished tubes are glued into the wing and stabilizer. The holes for these tubes are first pierced with a sharp pencil in the places shown in the figure.
To ensure the flight of the model, the following conditions must be met immediately after assembly. The plane of the stabilizer should be glued in relation to the lower plane of the wing at an angle of 3-5°. That is why gluing the tubes into the wing and stabilizer must be done as carefully as possible. If you still end up with some discrepancies, correct them by bending the fuselage rail. Of course, to fully fine-tune the model, more careful adjustment of the position of the fuselage curved relative to the wing and stabilizer will be required.
In flight, canard models (this paper glider is made according to this design) tend to pitch up, that is, lift up the nose, which leads to an increase in drag and a decrease in speed.
In such cases, they either change the angle of installation of the stabilizer relative to the wing, or reduce the area of the stabilizer by cutting it with scissors, or slightly bend the tips upward.
The center of gravity of the glider should be ahead of the leading edge of the wing. Therefore, if necessary, attach an additional weight - a piece of plasticine - to the forward part of the fuselage. Carry out the necessary centering of the model by starting it by hand. If the glider dives steeply, then you need to increase the angle of installation of the stabilizer or reduce the weight of the cargo. If the model plans well, you can start launching it on the rope. To do this, use thread and glue to install hook 4 on the fuselage. To make the model fly in circles, adjust the angle of the wing tail.
Based on materials from the book by V.A. Zavorotov "From idea to model".
In a modern aviation club, in addition to airplanes, helicopters and parachute jumps, you can also learn to fly a glider. Gliding flights instill the right attitude towards air transport piloting skills and lay a reliable foundation for the flying profession. And amateur pilots can take a fresh look at freedom of flight: there is no engine, no noise, and to increase the flight duration you need to feel air currents. What types of gliders are there: classes and types, their cost and characteristics.
For the normal organization of a glider flying club, it is necessary to have the following types of gliders in the fleet: two-seat gliders, single-seat gliders for athletes and ultra-light single-seat gliders for amateurs. Devices for training must be reliable, forgiving of errors and at an affordable cost, the rest of the groups are for those who need a high-quality product or rental service at an affordable cost.
Consumer properties of gliders
There are different types of gliders: wooden, metal, fiberglass. They can also be ultralight and regular, as well as single, double and even triple. The most suitable classification in in this case is the division of soaring ships by cost: category up to $10,000, up to $25,000 and above.
What might a glider be thinking about when making a purchase? Usually they pay attention to the aerodynamic quality, the presence and brand of the main engine, the novelty of the instrument panel and on-board computer. Connoisseurs may have higher demands: quality under 60 units, hydrocarbon spars in the wings, a fuselage made of Kevlar and a sticker on board: “The world champion flies on this glider.”
What to look for when purchasing aircraft? If you have chosen a category that is suitable for you, then here is a list of questions, the answers to which will help you choose the right model:
- Sustainability. The ability of the glider to stay in the flow, including feeling microlifts. If you want to be in a flow in which not every bird stays, come home late in the evening on tiptoe, anticipating a repeat flight the next day, then choose the appropriate glider.
- Cabin volume. American gliders are usually wider than their European counterparts, and not every glider allows you to stretch out to your full height. The determining parameter is the length of the space for the pilot: it is better to choose a narrow but long cabin.
- Maintainability. How labor-intensive is it to carry out repairs and bring the device into working condition? Many people believe that fiberglass lasts forever, but not the outer layer of the fuselage. The cost of restoring a modern airframe can be higher than the cost of a used airframe.
- Technical specifications. Aerodynamic quality, low speed stalling, no failures in technical level in addition to stability. Is it worth it to squeeze maximum performance out of your horse every day? You usually need to enjoy flying; competitions don’t happen often.
- Price. Available. Each buyer according to his needs, depending on his lifestyle and preferences.
- Equipment and facilities. Backlit monitors are at the pinnacle of progress, as are flight computers, but no computer can replace a pilot in flight. Before making an expensive investment in a gadget, read “Technique and Practice of Soaring Flights” by Goncharenko; first of all, you need to feel the flight with your fifth point.
- Ability without harm to the device land on an unprepared site. Glider with good technical characteristics A glider that can land in a field is of greater value to the glider than a glider that has a lift-to-drag ratio of 60 but suffers from landing off the runway. Therefore, when purchasing, it is also important to look at the adaptability of the airframe to your landing strip: it may be worth taking care of the presence of a retractable landing gear with a reliable shock absorber, instead of a rigid crutch in the front part of the fuselage.
- Caravan. Possibly the most underrated item when buying a glider. How much effort is required for installation and dismantling, how labor-intensive is assembly and disassembly? At the same time, the device must be safe during transportation.
TOP best two-seat gliders for learning to fly
Any training begins with communication and close contact with the instructor, the person who introduces you to the world of flight. The closer the contact, the faster the experience and understanding of the specifics of air flight in a glider comes. This problem is solved by a two-seater device: the glider must be reliable, forgive mistakes, be repaired faster and cheaper, and also have an affordable price.
1. Blanik L-13 and L-23
The most common gliders with quality 28 (32). The cost of a used one is 350,000 - 570,000 rubles depending on the year of manufacture, and a 10-year-old Blahnik L-23 can be purchased for $31,500 with 2,000 flight hours.
Blahnik is a Blahnik in Africa too: it holds steady in traffic, a fairly spacious cabin, the appearance of outdated instruments brings joy to many, maintainability is like a Soviet car, in general there are only advantages. Now about the disadvantages: rather tight controls are quite common, technical characteristics are at the level of 60 years and problems with transportation, which result in the need for a special trailer to transport the device safely.
As for flight reliability, despite the introduction of restrictions on the operation of glider flights in the world, the operation of the sports version of the Blanik L-13 AC glider among glider pilots is considered more reliable when performing aerobatic flights.
2. AC – 7. Quality 40, maximum take-off weight 700 kg, cost 55,000 €
Glider Russian manufacturer with good ones consumer properties: low cost is one of the advantages, other parameters are at the level of European analogues, there is also a clear advantage that a special trailer for transportation has been developed and sold, costing 21,000 €.
This glider has one feature that sets it apart somewhat from other gliders: the transverse position of the pilots in a spacious cockpit with a wide view. Interesting solution for those who have decided to fall in love with gliding flights for a long time: the instructor sits next to you at the same level, you can talk about the beauty and serenity of flight, but at the same time maintain internal discipline to develop the necessary piloting skills.
3. DG – 1000. Quality 47, cost about $140,000
An excellent European glider for initial flight training and consolidation of existing skills. Interestingly, it was these airframes that replaced the obsolete Blahniks at the US Air Force academies. As for consumer qualities, everything is excellent, with the exception of the somewhat overpriced and cramped cabin.
4. ASK – 21 Schleicher with motor. Cost 135,000 €. A used one 25 years old with 5,000 flight hours can be purchased for 42,000 €
Volkswagen in the world of gliders: the people's glider from the Germans.
German reliable study desk for beginner glider pilots: the glider is in great demand because it forgives many mistakes and has soft flight characteristics. In addition, the presence of a second bow auxiliary wheel together with the main one allows you to hold good stability during takeoff and landing.
5. Grob 103 Twin 2. The motor glider costs about 116,000 €, the cost of a used one for 25 years with 4200 flight hours is about 36,250 €
Fiberglass fuselage designed for training and simple aerobatics.
Compared to ASK-21, Grob makes greater demands on piloting skills, does not forgive negligent behavior and requires a more conscious approach to training. Most glider pilots on Western forums agree that the Grob's yaw and pitch controls are less well balanced than the Ask's.
The best single-seat gliders for athletes. Main evaluation criteria: cost, stability and technical characteristics
1. Amber Standard 2. Aerodynamic quality 40. Cost of a used one 25 years 18340 € with 650 flight hours
Single-seat sports apparatus of standard class. In Russian flying clubs it is considered the next step in training after Blahnik, and is widespread everywhere. The advantages of this airframe are its reliability and maintainability, but the disadvantages are its narrow cabin.
2. ASW – 19. German “hunchbacked horse”. Quality 39. Cost of a used glider from 29,000 € - 36,250 €
Frisky device from German manufacturer, you should be on guard with him, and he will also please low cost and German reliability, but this is all for experienced glider pilots. The later model of the airframe Asw - 28 has an even larger fuse, but the cost is higher.
3. Discus 2b. A 5 year old glider can be purchased for 85,000 €. Quality 46. Wingspan 12 meters
Good technical characteristics for its price category, as well as German quality and stability in flight, will give you the opportunity to experience the possibilities of flying on a modern standard-class sports glider.
4. Rolladen Schneider LS – 8. 18 meter class glider, quality 43, empty weight 240 kg and cost 58800€ for an 18 year old with 2540 flight hours
The glider became commercial successful project German company, at championships different levels won many victories over its main competitors: DG and SW gliders. It is very popular due to its flight qualities.
5. Nimbus 4. The dream of many glider pilots on the other side of borders and oceans: a song in the world of gliders with a wingspan of 26.5 meters
The flight of this glider resembles the flight of a bird with flapping wings, the quality of the glider is about 60, the cruising speed is 165 km/h. Disadvantages: the cost in the version with a retractable engine is about 200,000 € (used for 20 years, about 80,000 € - 100,000 €), as well as high requirements for the quality of service and take-off and landing within the prepared runway, otherwise repairs will cost a pretty penny.
Review of ultra-light single-seat gliders for hobbyists
Flying a glider can be a great way for teenagers to discover their way to the sky, and for hobbyists great way relax and gain strength and energy. As for teenagers, in a single seat you can get off the ground and practice the initial skills of holding a glider in roll and pitch. Amateur glider pilots, in addition to saving money, will find it useful to buy without having to undergo registration, certification and obtain a glider pilot's license. In Russia, the class of ultra-light gliders also includes devices with a weight limit of 115 kg. The qualities of a product are determined, first of all, by the ability quick assembly, cheap transportation, as well as stability in the flow.
1. AC - 4. “Ultralight”. The Russian answer to Chamberlain costs 26,500 € and weighs an empty airframe of 110 kg with a quality of 30
A high-quality Russian product on the global gliding market. Initially, the glider took second place in the competition for selecting a glider model for the “world class” championships: the idea was to hold competitions on one glider model, and the first place was given to the Polish PW-5 due to the well-established mass production at that time, although inferior in most respects. Now to the point: easy to fly, “controlled by the power of thought,” so it is recommended to have some experience in flying training gliders and an initial foundation of piloting skills. Works well in narrow streams. Tightened on a paraglider winch. And the absence of the need for registration, certification and a glider pilot certificate allows you to save money. Now for the disadvantages: low maintainability and poor stability in flows.
2. Sparrowhawk. Cost $44,500. The wingspan is 11 meters. 70 kg empty weight
Products of the American company Winward Performance based on cutting-edge expensive materials with high specific strength (carbon fiber reinforced plastics). The advantage of the glider is its reliability and good flight characteristics.
3. Archaeopteryx. Aerodynamic quality 28, cost of the basic model 75300 €, empty airframe weighs 57 kg
An interesting idea for a foot-launched glider, with good technical characteristics and soft controls. The device will allow you to enjoy your flight, provided you carefully follow technical parameters reliability and speed: loads up to +4, -2 G, maximum speed 130 km/h, stall speed 30 km/h.
4. Banjo MH. Czech glider is almost a single copy, with aerodynamic quality 28
Stability in flow is average, repair only from original material, the cost is acceptable for many. The name of this glider is borrowed from the 4-string banjo guitar, and the designers are true lovers of soaring and soaring technology. It can be a good simulator for developing soaring skills. The cost of the device is about 21,500 €
The list of gliders is not exclusive, but it will give some idea of what should be taken into account other than aerodynamic efficiency. General rule like, “It’s a Mercedes everywhere,” so it’s worth taking a closer look at it, this is what concerns expensive and quality models. And others are tried and tested gliders, made with love.
Are high technical characteristics so important?
Oddly enough, but high aerodynamic quality matters only when you are a participant in a competition (European Championship, competition with a friend, etc.). When flying freely from competitions on a simpler glider, Yantar Standard or Nimbus 3, there is unlikely to be a desire to evaluate the quality of the flight. Usually glider pilots evaluate their achievements by other criteria: who rose higher in the flow, who flew further. Of course, competition with a fellow party member is of great importance for authority, but victory over oneself and one’s own heights is much more important.
Good climbing speed in traffic, a spacious cabin, a short runway, well, so be it, aerodynamic quality, ease of towing and low cost, perhaps that’s all. But the ideal glider is only in dreams, and in reality you can only fly with what you have and for your price.
I had a drawing of this model for several years. Knowing that it flies well, for some reason I could not decide to build it. The drawing was published in one of the Czech magazines in the early 80s. Unfortunately, I was unable to find out either the name of the magazine or the year of publication. The only information that is present on the drawing is the name of the model (Sagitta 2m F3B), the date - either construction or production of the drawing - 10.1983 and, apparently, the first and last name of the author - Lee Renaud. All. No more data.
When the question arose of building a glider that would be more or less equally suitable for flying in both thermals and dynamics, I remembered a drawing that was lying idle. One careful examination of the design was enough to understand that this model is very close to the desired compromise. Thus, the problem of choosing a model was solved.
Even if I have a ready-to-use drawing of a model at my disposal, I still redraw it with my own hand, with a pencil on graph paper. This helps to thoroughly understand the structure of the model and simplifies the assembly process - you can immediately develop the sequence of manufacturing parts and their subsequent installation. So construction started from the drawing board. The design of the airframe included minor changes, which made it possible to fearlessly tighten the model both on the handrail and on the winch.
Intensive use of the glider in the summer of 2003 showed that it is distinguished by predictability, stability and, at the same time, agility - even without ailerons. The glider behaves quite satisfactorily both in thermals, allowing it to gain altitude even in weak currents, and in dynamic conditions. I note that the model turned out to be too light, and sometimes additional loading of the airframe is required - from 50 to 200 grams. For flights in strong dynamic currents, the glider has to be loaded more - by 300...350 grams.
The model can be recommended for beginners only if the training is carried out together with an instructor. The fact is that the model has a relatively weak tail boom and bow. This does not cause any problems if you at least know how to land a glider, but strong blow The model may not be able to withstand its nose touching the ground.
Characteristics
The main characteristics of the airframe are:
Materials required for manufacturing:
- Balsa 6x100x1000 mm, 2 sheets
- Balsa 3 x100x1000 mm, 2 sheets
- Balsa 2 x100x1000 mm, 1 sheet
- Balsa 1.5 x100x1000 mm, 4 sheets
- Duralumin plate 300x15x2 mm
- Small pieces of plywood 2 mm thick - approximately 150x250 mm.
- Thick and liquid cyacrine - 25 ml each. Thirty minute epoxy resin.
- Film for covering the model - 2 rolls.
- Small pieces of 8 and 15 mm balsa - approximately 100x100 mm.
- Pieces of textolite 1 and 2 mm thick - 50x50 mm is quite enough.
The production of the glider takes less than two weeks.
The design of the model is very simple and technologically advanced. The most complex and critical components - the attachment of the consoles to the fuselage and the rocking of the all-moving stabilizer - will require maximum care and attention when building the model. Carefully study the airframe design and assembly technology before starting its construction - then you will not waste time on alterations.
The description of the model is intended for modelers who already have basic skills in building radio-controlled models. Therefore, constant reminders “check for distortions”, “carefully do [this]” are excluded from the text. Accuracy and constant control are things that go without saying.
Manufacturing
Please note that unless otherwise noted in the text, all balsa pieces have grain along the longer side of the piece.
Fuselage and tail
We'll start building the glider with the fuselage. It has a square cross-section; made of balsa 3 mm thick.
Take a look at the drawing. The fuselage is formed by four balsa plates 3 mm thick - these are two walls 1, as well as the upper 2 and lower 3 covers. All frames 4-8, except frame 7, are made of 3 mm thick balsa.
Having cut out all the necessary parts, we tinker with the manufacture of frame 7 from three- or four-millimeter plywood. After this, having installed the frames on the drawing covered with transparent film, we glue the walls to them. Having removed the resulting box from the drawing, we will glue the bottom cover of the fuselage, and then we will lay down the bowdens 9 for controlling the elevator and rudder (and, if desired, a tube for laying the antenna).
Let's work on the forward part of the fuselage. We will assemble the nose boss 10 from scraps of thick balsa, the removable canopy will be made from balsa with a thickness of 3 (walls 11) and 6 ( upper part 12) millimeters. We are not installing control equipment yet. The only thing you need to do is try it on in place. If necessary, you can remove frame 6, which is more of a technological element than a power element.
We move on to the middle part of the fuselage, to which the wing is attached. We have to make a plywood box 13, which ties together the wing spar, the fuselage itself and the towing hook. The details of the box are shown in a separate sketch. It consists of two walls 13.1 and a bottom, represented by plywood from parts 13.2 and 13.3. We stock up on two-millimeter plywood, a pair of jigsaw files, and get started.
Having assembled the box "dry", we adjust it to the inside of the fuselage, and then glue it in. We will make cuts for the connecting guide of the consoles later, locally. Other holes in the box are also made locally.
After installing the box, you can glue the top fuselage cover 2.
One of the most difficult stages of fuselage assembly begins - manufacturing, fitting and installation of the fin and stabilizer rocker.
As we can see from the drawing, the keel (it is very small, since the rest is the rudder) is formed by a frame of the front 14, rear 16 and top 15 edges, made of two-millimeter balsa and glued between the sides of the fuselage.
The stabilizer rocker 17 is mounted in the frame, and then the side lining is glued to the frame - the keel walls 18 are made of 3 mm thick balsa.
The removable halves of the stabilizer are mounted on a power pin 19 made of steel wire with a diameter of 3 mm, and are driven by a short pin 20 ( steel wire 2 mm), glued into the front part of the rocker. The rocking chair is made of textolite 2 mm thick, or plywood of the same thickness. Between the rocker and the walls of the keel, thin washers are installed, mounted on a power pin.
It looks simple - we cut out all the parts and put them together. Be extremely careful!!! Once the frame that forms the keel is assembled and the lining is glued to one side, you will begin to install the elevator rocker, connect the bowden to it and get ready to glue the keel wall on the other side.
This is where the main ambush awaits you: if even a drop of thiacrine gets on the rocking chair, which is installed between the walls of the keel without large gaps, all is lost. The rocking chair will dry tightly to the wall, and the keel assembly will have to be repeated again. You should be especially careful when gluing the power three-millimeter steel pin - cyacrine can very easily get inside the keel along it. Use thick glue.
After assembling the keel, do not forget to glue the textolite pads 21, which secure the power pin from distortion.
Finally, we will install fork 22 and sand the fuselage.
Assembly of the rudder and stabilizer is so simple that it does not pose any difficulties. I will only note that the holes for the power pin in the halves of the stabilizer after drilling are impregnated with liquid cyacrine and then drilled again.
Please note that the front parts of the handlebars are made of whole pieces balsa (8 mm thick on the rudder and 6 mm thick on the stabilizer). This significantly simplifies the process of assembling the model, but does not add unnecessary weight, because, as already mentioned, the airframe is already too light.
Having assembled and profiled the rudders, we’ll “roughly” hang them in place and check the ease of movement. Everything is fine? Then we’ll remove them, put them away and move on to the wing.
Wing
The wing design is so standard that it should not raise any questions at all. This is a stacked balsa frame with a forehead 8 sewn up with balsa 1.5...2 mm thick, ribs 1-7 made of two-millimeter balsa with flanges made of balsa 1.5...2 mm thick, and a wide rear edge 11 (balsa 6x25). Spars 9 are pine slats with a section of 6x3 mm, between them a wall of balsa 10 with a thickness of 1.5...2 mm is mounted.
It should be noted that the spar, in general, will be flimsy for such a scope - in case the airframe has to be tightened with a winch. Its strength is quite sufficient for manual tightening.
To avoid “firewood,” I had to glue strips of carbon fabric to the outside of each of the spar flanges. After this improvement, the glider allowed itself to be pulled on a modern winch for F3B class gliders. The consoles, of course, bend, but they hold the load. At least for now...
Wing assembly begins with the manufacture of ribs. The center section ribs are processed in a “package” or “bundle”. This is done like this: let's make two rib templates from plywood 2...3 mm thick, cut out the rib blanks and assemble this package together using M2 threaded pins, placing the templates along the edges of the package. After processing, this solution will provide the same profile along the entire span of the center section. In the drawing, the center section ribs are numbered "1", and the ear ribs are numbered from "2" to "7".
We will do things differently with the ribs of the “ears”. By printing them on laser printer with maximum contrast, we will attach the printout to a sheet of balsa from which we will cut the ribs. After this, use a fully heated iron to iron the printout, and the images of the ribs will be transferred to the balsa. Just remember that the paper needs to be placed with the image on the balsa, and it is better to first sand the balsa itself with fine sandpaper. Now we can start cutting out the printed parts. At the same time, prepare the details of the lining of the forehead 8 and the center section 12, cut strips of balsa for the flanges of the ribs 14, prepare the blanks of the leading edges 13 and the walls of the spar 10, profile the rear edges 11. Please note that the walls of the spar 10 have a different direction of the wood fibers from other parts - along the short sides. Upon completion of preparation, we can begin assembling the wing without being distracted by the manufacture of the required parts.
First we make the center section parts. We attach the lower flange of the spar to the drawing, install the ribs on it and install top shelf spar. Then we glue the walls of the spar made of three-millimeter balsa 15, located in the root part of the wing. After this, we wrap the resulting box with threads. Let's coat the threads with glue.
We will carry out a similar operation on the other side of the console - where the “ear” will be attached. Only the walls in this case will be made of two-millimeter balsa. Having glued the balsa walls of the spar, we wrap the resulting box. In the future, it will include a guide for attaching the “ear”
Please note that the root rib adjacent to the center section is not installed perpendicular to the spar and edges, but under small angle.
The next step is gluing the back edge. Needless to say, this operation, as well as the next one, is also carried out on a slipway.
Assembling the front part of the wing. The order is as follows: the bottom lining, then the top, then the spar wall made of 1.5 or 2 mm thick balsa. Having removed the resulting console from the slipway, we glue the leading edge 13. Notice how the torsional strength of the wing sharply increases after the front is “closed.”
The final stage of assembling the center section is gluing the flanges of the ribs and the balsa lining of the root part of the wing (three central ribs).
The ear assembly is completely similar to the center section assembly and therefore is not described. The only thing worth noting is that the rib adjacent to the center section is not installed vertically relative to the plane of the wing, but at an angle of 6 degrees - so that there is no gap between the “ear” and the center section. We again wrap the root part of the “ear” spar with threads and glue.
Now let's take a long narrow knife and a file in our hands. We have to make holes for the center section guides 15 and the “ear” 16 in the boxes formed by the spar and its walls - two in the center section and one in the “ear”. Having cut through the balsa end ribs, use a file to level them inner surface boxes We don’t glue the “ear” with the center section yet. We assemble the second console in a completely similar way and proceed to the manufacture of guides.
The center-section guide carries the entire load applied by the handrail to the model when tightened. Therefore, it is based on a strip of duralumin 2...3 mm thick. It is processed so that it fits into the box designed for it without effort or play. After this, a similar-shaped plywood overlay is glued to it with thirty-minute resin, one or two - it depends on the thickness of the duralumin and plywood used. The finished guide is processed so that both consoles fit onto it with little effort.
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The guides, intended for attaching the “ears” to the center section parts of the wing, are made from three pieces of two-millimeter plywood, glued together to obtain a total thickness of 6 mm. Once you have made the guides for the "ears", the "ears" can be glued to the center section parts. It is best to use epoxy resin for this.
All that remains is to glue in the “tongues” 17 and the console fixing pins 18. Two-millimeter plywood is used for the “tongues”, and beech, birch or thin-walled aluminum or steel tube is used for the pins.
That's all, actually. All that remains is to cut out windows for the guide and “tongues” in the center section of the fuselage and drill holes for the wing fixation pins. Keep in mind that here it is necessary to control both the absence of mutual distortions between the wing and stabilizer, and the identity of the installation angles of the left and right consoles. Therefore, take your time and take your measurements carefully. Think: maybe there is a technology that is convenient for you, allowing you to avoid possible flaws when cutting out windows?
Final operations
Now you need to make the cover of the center section of the fuselage compartment 23. It is made of balsa or plywood. The method of attaching it is arbitrary; it is only important that it is removable and firmly fixed in its place. After the lid is made, drill a hole with a diameter of 3 mm in it and the connecting tongues. A pin with a diameter of 3 mm, then inserted into these holes, will not allow the consoles to move apart under load.
To increase the strength of the fuselage at the point where the wing guide is attached, we will have to make another one structural element 24, formed by four struts inside the fuselage, made of three-millimeter plywood. Having inserted guide 15 into the holes prepared for it, we will glue these spacers close to it. We got a kind of “channel” for the guide. It will prevent it from moving too freely in the holes and at the same time add rigidity to the fuselage. Glue the fifth piece of “three rubles” approximately 100 mm closer to the tail. It turned out that the balsa fuselage in the center section was reinforced with a closed box made of plywood. This scheme has fully justified itself in practice.
Now is the time to glue and process the ends of the “ears” 19. After this, you can start balancing the model and check whether one of the consoles is overweight.
Covering the airframe is not too difficult. If this is your first time, read the instructions for using the film. It usually describes in detail how to use this particular film.
Installation of radio control equipment should not cause any special difficulties - just look at the photographs.
Don't forget that the stabilizer on the model is all-moving. Its deviations in each direction should be 5...6 degrees. And even at such costs, it may turn out to be too effective, and the model may be “twitchy”.
The rudder deflection angles should be 15...20 degrees. It is advisable to seal the gap between the rudder and the keel with tape. This will slightly improve the steering efficiency.
Towing hook 25 is made of duralumin angle. Its installation location is indicated in the drawing.
We will cut weights from lead plates about 3 mm thick - they should be shaped like the center section of the fuselage. The total weight of the “sinker” should be at least 150 grams, and better – 200…300. Based on the number of plates in the fuselage, you can adjust the model to different weather conditions.
Don't forget to center the model. The location of the CG on the spar will be optimal for the first (and not only) flights.
The airframe described here was manufactured without ailerons. If you feel like you can’t live without them, install them. If it doesn’t seem like it, don’t fool yourself, the model is controlled quite normally by the rudder.
However, the drawing shows the approximate size of the ailerons. You can think about the fastening of the aileron steering gears yourself. Of course, from the point of view of aerodynamics and aesthetics, it is best to use mini cars.
Flying
Tests
If you assembled the model without distortions, then there will be no special problems with testing. Choosing a day with a steady, gentle wind, go to a field with thick grass. Having assembled the model and checked the operation of all rudders, take a running start and release the glider into the wind at a slight descent angle or horizontally. The model must fly straight and respond to even small deflections of the rudder and elevator. A properly configured glider flies at least 50 meters after a slight hand throw.
Start on the rope
When preparing to launch from the rope, don’t forget about the block. The glider is quite fast, and in light winds problems may arise with the lack of speed of the drawer, even when tightening with a block.
The diameter of the handrail can be 1.0…1.5 mm, length - 150 meters. It is preferable to place a parachute at its end rather than a flag - in this case, the wind will pull the line back to the start, reducing the distance you or your assistant runs in search of the end of the line.
After checking the functioning of the equipment, attach the model to the rail. After giving your assistant the command to start moving, hold the glider for as long as you can. Meanwhile, the assistant must continue running, stretching the rope. Release the glider. At the initial moment of takeoff, the elevator must be in neutral. When the glider gains 20..30 meters of altitude, you can slowly begin to take the handle "on yourself". Don't take too much, otherwise the glider will leave the rail prematurely. When the model reaches its maximum altitude, vigorously push the rudders down, putting the model into a dive, and then towards yourself. This is the so-called "dynamo start". With some practice, you will understand that it allows you to gain a few more tens of meters in height.
Flight and landing
Keep in mind that when the rudder is sharply applied in any direction, the glider is prone to some directional swing. This phenomenon is harmful because it slightly slows down the model. Try to move the rudder stick in small, smooth movements.
If the weather is practically calm, the glider may not be loaded. If you have problems flying against the wind or entering thermals, add 100-150 grams to the model. The ballast mass can then be selected more accurately.
Planting, as a rule, does not cause any trouble. If you have built a glider without ailerons, try not to make large rolls low above the ground, because the model will respond late to rudder deflection.
Interestingly, additional loading has virtually no effect on the model’s ability to soar. The loaded glider holds up well even in relatively weak updrafts. Longest time flight in thermals, achieved during the operation of the model - 22 minutes 30 seconds.
And the same additional load is simply necessary for flying in dynamic flows. For example, for a normal dynamo flight in Koktebel, the glider had to be loaded to the maximum - 350 grams. Only after this did he gain the ability to move normally against the wind and develop amazing speeds in a dynamic flow.
Conclusion
Over the past season, the model has shown itself to be a good glider for amateurs. However, this does not mean that it is completely without shortcomings. Among them:
- profile too thick. It would be interesting to try using an E387 or something similar on this airframe.
- lack of developed wing mechanization. Strictly speaking, initially the airframe contained both ailerons and spoilers, but in order to simplify the design and develop precision landing skills, it was decided to abandon them.
However, the rest of the airframe is designed “excellently”.
An electric glider based on the described model is currently under construction. The differences are in the reduced wing chord, modified profile, presence of ailerons and flaps, fiberglass fuselage, and much more. Only the general geometry of the prototype has been preserved, and even then not everywhere. However, the future model is the topic of a separate article...
TABLE OF CONTENTSIntroduction 3
Chapter I. Necessary information from aerodynamics 8
Chapter II. Gliding and soaring flight 25
Chapter III. Elements of the theory of the glider model 36
Chapter IV. Calculation of the glider model 48
Chapter V. Launching the glider model 59
Chapter VI. Building glider models 76
Chapter VII. Development of the glider model 92
Chapter VIII. Flying model of a glider in the USSR 103
Applications 126
Over the past four years, our Soviet aircraft modeling industry has placed itself in one of the first places in the world in terms of technical achievements. But if we get acquainted with our records, we will be convinced that until 1934 the attention of modellers was focused mainly on a flying model of an airplane with a rubber engine. The great merits of Soviet aircraft modeling on these models should be recognized: 1) the creation of a fuselage model diagram adapted for long-distance flight on a rubber engine (type of Miklashevsky flight model), 2) the creation of a fuselage model diagram adapted for record-breaking, very long and long-distance flights in updrafts air (type of Zyurin models) and 3) creation of a class of flying models - copies of aircraft that are not inferior in their flight performance to the average record models.
Non-motorized models - flying models of gliders - occupied our modelers less than motorized ones. The coldness of the guys towards glider models was explained by the opinion that glider models “fly worse than motorized ones,” and of course it was not interesting to build a worse flying model. The opinion about the limited flight capabilities of glider models had some basis. For a long and long flight, the glider model needs suitable place launch, namely, hills of sufficient height and the presence of appropriate wind, i.e. approximately the same conditions as for the flight of a full-size glider. Until 1934, the starts of glider models at all-Union rallies were held not far from the starts of motor models, and it is clear that on flat (or almost flat) terrain there was no reason for glider models to chase their motor counterparts. The lack of a good start for glider models limited their flight capabilities, and this, of course, could not but affect the popularity of the glider model in the eyes of our modelers. Therefore, in terms of glider models, we had a very strong lag behind foreign countries, as a result of which in 1934 the Soviet aircraft modeling industry was given the task: to reverse special attention on glider models and achieve world records for range and duration using these models.
The year 1934 was a turning point. In 1934, the launch of glider models in Koktebel was fully mastered, a world record for the flight duration of a glider model was set (today this record has already been surpassed by our own modelers) and a well-known direction was given for the construction of a well-flying record-breaking non-motorized model (Fig. 1) . The attention that was paid by our leading aircraft modeling organizations to glider models is, of course, explained not only by the desire to win the world championship in this area of youth airsports; glider models are very important from the point of view of improving the aviation culture of our modelers; working on a model contributes to a natural transition from a glider model to a glider, since on a glider model it is possible for an aircraft modeler to study the physics of glider flight, glider meteorology and some design forms of “real-life” gliders.
The glider model is no less interesting than the airplane model. It is possible to construct such simple model a glider that can be built by a modeller, like the first flying model, and with its flights will seduce him no worse than a motor model, on which he would spend more time. Flying glider models can be used for experimentation when working on new aircraft shapes. Some “buts” in this matter may be the fact that the model is uncontrollable in flight and always flies at the same mode (angle of attack of the wing), while a real aircraft is controllable and can change angles of attack in flight at the request of the pilot. You can install a simple mechanism on a glider model that can suddenly change its flight mode. An example of such a mechanism is a windmill (Fig. 2), which has an axis with a screw thread; this axis, as the windmill rotates from the oncoming air flow, turns out of the coupling; it will completely turn out of the clutch, the latter, being free, will move under the influence of spring a, thereby removing needle c, which holds spring b from contracting, from the piston? The contracted spring will force the angle of inclination of the corresponding steering surfaces to change. weight, so that it can be equipped with a glider model with a span of even 1.2 - 1.3 m. An aircraft modeler who will build and launch flying glider models for research purposes will, firstly, expand his knowledge and be able, secondly, bring real benefits to aircraft technology.
The glider model can serve as a good teaching aid when studying gliding and soaring flight in gliding schools, aviation colleges, for demonstration at lectures, etc. It would be very interesting to build a flying model of a glider controlled by radio
from a two-seater glider. With a wingspan of 4 - 5 m and a control radius of 1 km similar device could be used to "feel" for upward flows.
The glider model can also be used as a target when firing anti-aircraft artillery.
Until now, there has been no guidance literature on glider models, but the need for it has long been overdue. This book is the first attempt to fill this gap and provide the qualified modeler with the necessary material.
Below we give a table of achievements by glider models in the USSR, USA and Germany...