Long years gyroplanes were considered very dangerous aircraft. Even now, 90% of those who fly believe that gyroplanes are deadly. The most popular saying about gyroplanes is: “They combine the disadvantages of airplanes and helicopters.” Of course this is not true. Autogyroplanes have many advantages.
So where does the opinion about the colossal danger of gyroplanes come from?
Let's take a short excursion into history. Autogyros were invented in 1919 by the Spaniard de la Cierva. According to legend, he was prompted to do this by the death of his friend on the plane. The cause of the disaster was a stall (loss of speed and loss of lift and controllability). It was the desire to design an aircraft that was not afraid of stalling that led him to the invention of the gyroplane. La Cierva's gyroplane looked like this:
Ironically, La Cierva himself died in the plane crash. True, passenger.
The next stage is associated with Igor Bensen, an American inventor who in the 50s came up with a design that formed the basis of almost all modern gyroplanes. If Sierva's gyroplanes were, rather, airplanes with an installed rotor, then Bensen's gyroplane was completely different:
As you can see, the tractor engine arrangement has changed to a pushing one, and the design has been radically simplified.
It was this radical simplification of the design that played an evil role with gyroplanes. They began to be actively sold in the form of kits (sets for self-assembly), become “craftsmen” in garages, actively fly around without any instruction. The result is clear.
The mortality rate on gyroplanes has reached unprecedented levels (about 400 times higher than on airplanes - according to the English statistics of the 2000s, it included ONLY Bensen-type gyroplanes, various types of homemade ones).
At the same time, the control and aerodynamic features of the gyroplane were not properly studied; they remained experimental devices in the worst sense of the word.
As a result, serious mistakes were often made during their design.
Look at this device:
It seems to be similar in appearance to modern gyroplanes, photographs of which I provided in the first post. It seems like it, but it doesn’t look like it.
Firstly, the RAF-2000 did not have a horizontal tail. Secondly, the engine's thrust line ran significantly above the vertical center of gravity. These two factors were enough to make this gyroplane a “death trap”
Later, largely thanks to the RAF disasters, people studied the aerodynamics of the gyroplane and found the "pitfalls" of it, it would seem. perfect aircraft.
1.Rotor unloading
. The gyroplane flies thanks to a freely rotating rotor. What happens if the gyroplane enters a state of temporary weightlessness (updraft of air, top of the barrel, turbulence, etc.)? The rotor speed will drop, and the lift force will drop along with it... It would seem that there is nothing wrong, because such states do not last long - a fraction of a second, a second maximum.
2. Yes, no problem, if not for the high draft line, which can lead to power somersault
(PPO - power push-over).
Yes, I drew this again;)) The figure shows that the center of gravity (CG) is located significantly below the thrust line and that air resistance (drag) is also applied below the thrust line. The result is, as they say in aviation, a diving moment. That is, the gyroplane tries to somersault forward. In a normal situation, it’s okay - the pilot won’t give it. But in a situation where the rotor is unloaded, the pilot no longer controls the device, and it remains a toy in the hands of powerful forces. And he tumbles. And this often happens very quickly and unexpectedly. I was just flying and enjoying the views, and suddenly BAM! and you are already falling down into an uncontrollable tin can with sticks. Without a chance to restore controlled flight, this is not an airplane or a hang-glider.
3. In addition, gyroplanes have other strange things. This PIO (pilot induced oscillations - longitudinal swing provoked by the pilot
). In the case of unstable gyroplanes, this is very likely. The fact is that the gyroplane reacts somewhat slowly. Therefore, a situation may occur in which the pilot creates a kind of “swing” - trying to dampen the vibrations of the gyroplane, he actually strengthens them. As a result, the up-and-down oscillations increase and the apparatus turns over. However, PIO is also possible on an airplane - the simplest example would be the well-known habit of novice pilots to fight the “goat” with sudden movements of the stick. As a result, the amplitude of the “goat” only increases. On unstable gyroplanes, this very swing is very dangerous. On stable ones, treatment is very simple - you need to drop the “handle” and relax. The gyroplane will return to a calm state on its own.
The RAF-2000 was a gyroplane with a very high thrust line (HTL, high thrust line gyro), the Bensen ones - with a low thrust line (LTL, low thrust line gyro). And they killed a lot, a lot, a lot of pilots.
4. But even these gyroplanes could be flown if not for another discovered thing - it turns out that gyroplanes handle differently than airplanes
! In the comments to the last post, I described the reaction to engine failure (handle it away). So, in several articles I read about the exact opposite!!! In a gyroplane, if the engine fails, you need to urgently load the rotor by pushing the handle OUT and REMOVING the gas. Needless to say, the more experienced an airplane pilot is, the more powerful the reflex sits in his subcortex: when he refuses, pull the stick away and turn the throttle to maximum. In a gyroplane, especially an unstable one (with a high line of thrust), such behavior can lead to that very forceful somersault.
But that's not all - gyroplanes have a lot different features. I don’t know all of them, because I haven’t completed the training course myself yet. But many people know that gyroplanes are not so fond of “pedals” during landing (sliding, with the help of which “airplanes” often “gain altitude”), do not tolerate “barrels” and much more.
That is, on a gyroplane it is vitally important learn from a competent and experienced instructor
! Any attempts to master a gyroplane on your own are deadly! That doesn’t stop a huge number of people around the world from building and constructing their own stools with a screw, mastering them on their own and regularly fighting on them.
5. Deceptive simplicity
. Well, the ultimate pitfall. Gyrocopters are very easy and pleasant to control. Many people make independent flights on them after 4 hours of training (I took off on a glider at 12 o’clock; this rarely happens before 10 o’clock). Landing is much easier than on an airplane, the shaking is incomparably less - that’s why people lose their sense of danger. I think this deceptive simplicity has killed as many people as somersaults with swings.
The gyroplane has its own “flying envelope” (flight restrictions) that must be observed. Exactly as in the case of any other aircraft.
Games are not good:
Well, that's all the horrors. At some stage in the development of gyroplanes, it seemed that everything was over, and gyroplanes would remain the lot of enthusiasts. But the exact opposite happened. The 2000s became the time of a colossal boom in gyroplane manufacturing. Moreover, the boom of FACTORY gyroplanes, and not homemade and semi-homemade whales... The boom is so strong that in 2011, 117 gyroplanes and 174 ultra-light aircraft/glitters were registered in Germany (a ratio unthinkable back in the 90s). What’s especially nice is that the lshiders of this market, which has only recently emerged, demonstrate excellent security statistics.
Who are these new gyroplane heroes? What did they come up with to compensate for the seemingly enormous shortcomings of gyroplanes? More on this in the next episode;)
Lightweight autogyro DAS-2M.
Developer: V. Danilov, M. Anisimov, V. Smerchko
Country: USSR
First flight: 1987
For the first time, the DAS gyroplane took to the air in a non-motorized version, towed by a Zhiguli car. This happened at one of the agricultural aviation airfields near Tula. But it took more years, during which the designers worked on the engine, before the most experienced LII test pilot V.M. Semenov, after just one run, took the DAS-2M into the air. This event was later celebrated at SLA competitions with a special prize from the Mil Design Bureau. The device, according to the test pilot, has good flight characteristics and efficient control.
Design.
The fuselage is of a truss, tubular, collapsible design. The main element of the fuselage is a frame consisting of horizontal and vertical (pylon) pipes with a diameter of 75 x 1, made of 30KhGSA steel. Attached to them are a towing device with a lock and an air pressure receiver, an instrument panel, a pilot's seat equipped with a seat belt, a control device, a three-wheeled landing gear with a steerable nose wheel, a power unit mounted on a motor mount with a pusher propeller, a stabilizer, a keel with a rudder, a ball main rotor hinge. An auxiliary tail wheel with a diameter of 75 mm is installed under the keel. The pylon together with struts with a diameter of 38 x 2, a length of 1260 mm, tubular beams of the main wheels with a diameter of 42 x 2, a length of 770 mm, made of titanium alloy VT-2, and braces with a diameter of 25 x 1, a length of 730 mm made of 30KhGSA steel form a spatial load-bearing frame, in in the center of which the pilot is located. The pylon is connected to the horizontal fuselage tube and the main rotor ball joint using titanium gussets. In the area where the gussets are installed, bougies made of B95T1 duralumin are installed in the tubes.
The power unit is with a pusher propeller. It consists of a two-cylinder opposed two-stroke engine with a displacement of 700 cm3 with a gearbox, a pusher propeller and an electric starter, a friction clutch for a rotor pre-spin system, an 8-liter gas tank and an electronic ignition system. The power unit is located behind the pylon, on the motor frame.
The engine is equipped with a redundant electronic contactless ignition system and a tuned exhaust system.
The pushing wooden screw is driven by a V-belt gearbox, consisting of drive and driven pulleys and six belts. To reduce torque unevenness, dampers are installed on the gearbox.
The main rotor with a diameter of 6.60 m is two-bladed. The blades, consisting of a fiberglass spar, foam filling and covered with fiberglass, are mounted with one horizontal hinge on a bushing located on the pylon. At the ends of the blades there are uncontrolled trimmers for adjusting the cone of the main rotor. The driven gear of the pre-spin gear and the main rotor tachometer sensor are installed on the main rotor axis. The gearbox is driven by cardan-spline shafts, an angular gearbox mounted on the pylon, and a friction clutch located on the engine. The friction clutch consists of a driven rubber roller mounted on the axis of the cardan-spline shaft, and a driving duralumin drum located on the engine axis. The friction clutch is controlled using a lever mounted on the control handle.
Changes in roll and pitch are carried out by a handle that affects the position of the lower control fork, connected by rods to the upper fork, which, in turn, leads to a change in the inclination of the rotor rotation plane.
Directional control is carried out by a rudder connected by cable wiring to pedals that control the nose wheel. To compensate for the hinge moment, the rudder is equipped with a horn-type compensator. The rudder and keel of a symmetrical profile are made of 16 plywood ribs 3 mm thick, pine stringers 5 x 5 mm, covered with percale and coated with nitro varnish. The fin is mounted on the horizontal fuselage tube using anchor bolts and two cable braces.
The gyroplane chassis is three-wheeled. The front steered wheel, measuring 300 x 80 mm, is connected to the pedals using a gear reducer with a gear ratio of 1:0.6, and is equipped with a parking brake drum type diameter 115 mm.
The instrument panel is located on the towing device truss. The instrument panel is equipped with a speed indicator, variometer, altimeter connected to an air pressure receiver, and tachometers for the main and pusher propellers. On the control handle there is a toggle switch for emergency engine stop and a friction clutch control handle. The control levers for the carburetor throttle valve and the device for forced disengagement of the gearbox gears of the pre-spin system are installed on the pilot's seat on the left. The ignition switch is located on the right. To the left of the instrument panel is the parking brake lever. All mechanisms of the gyroplane are driven using cables with Bowden sheaths.
Main rotor diameter, m: 6.60
Max. take-off weight, kgf: 280
Empty gyroplane weight, kgf: 180
Fuel weight, kgf: 7
Specific load, kgf/m2: 8.2
Power point,
-power, hp: 52
-Max. propeller speed, rpm: 2500
-screw diameter, m: 1.46
Speed, km/h,
-take-off: 40
-landing: 0
-cruising: 80
-maximum: 100
Rate of climb, m/s: 2.0.
Autogyro DAS-2M.
It can be said without exaggeration that the main thing in a glider-gyroplane is the main rotor. The flight qualities of a gyroplane depend on the correctness of its profile, weight, alignment accuracy and strength. True, a non-motorized vehicle in tow behind a car rises only 20 - 30 m. But flying at such an altitude requires mandatory compliance with all previously stated conditions.
The blade (Fig. 1) consists of the main element that absorbs all the loads - the spar, ribs (Fig. 2), the spaces between which are filled with foam plastic plates, and a trailing edge made of straight-layer pine slats. All these parts of the blade are glued together with synthetic resin and, after proper profiling, covered with fiberglass to give additional strength and tightness.
Materials for the blade: aircraft plywood 1 mm thick, fiberglass 0.3 and 0.1 mm thick, ED-5 epoxy resin and PS-1 foam. The resin is plasticized with dibutyl phthalate in an amount of 10–15%. The hardener is polyethylene polyamine (10%).
The manufacture of the spar, the assembly of the blades and their subsequent processing are carried out on a slipway, which must be sufficiently rigid and have a straight horizontal surface, as well as one of the vertical edges (their straightness is ensured by gouging under a pattern-type ruler, at least 1 m long).
The slipway (Fig. 3) is made from dry boards. During assembly and gluing of the spar, metal mounting plates are screwed to the vertical longitudinal edge (the straightness of which is ensured) at a distance of 400 - 500 mm from each other. Their upper edge should rise 22 - 22.5 mm above the horizontal surface.
1 – spar (plywood glued with fiberglass); 2 – overlay (oak or ash); 3 – trailing edge (pine or linden); 4 – plank (pine or linden); 5 – filler (foam); 6 – sheathing (2 layers of fiberglass s0.1); 7 – trimmer (duralumin grade D-16M s, 2 pcs.); 8 – rib (plywood s2, layer along)
For each blade, 17 strips of plywood should be prepared, cut according to the spar drawing with the outer layer lengthwise, with processing allowances of 2 - 4 mm per side. Since the dimensions of the plywood sheet are 1500 mm, in each layer the strips must be glued together at a rate of at least 1:10, and the joints in one layer must be spaced 100 mm from the joints in the next one. The plywood pieces are positioned so that the first joints of the lower and upper layers are 1500 mm from the butt end of the spar, the second and penultimate layers are 1400 mm, etc., and the joint of the middle layer is 700 mm from the butt end of the blade. Accordingly, the second and third joints of the prepared strips will be distributed along the spar.
In addition, you need to have 16 strips of fiberglass with a thickness of 0.3 mm and dimensions of 95x3120 mm each. They must first be treated to remove the lubricant.
The blades must be glued in a dry room at a temperature of 18 – 20°C.
MANUFACTURING THE SPARM
Before assembling the workpieces, the slipway is lined with tracing paper so that the workpieces do not stick to it. Then the first layer of plywood is laid and leveled relative to the mounting plates. It is attached to the slipway with thin and short nails (4-5 mm), which are driven in at the butt and at the end of the blade, as well as one on each side of the joints to prevent the plywood sections from moving along the resin and fiberglass during the assembly process. Since they will remain in the layers, they are hammered in randomly. The nails are driven in in the indicated order to secure all subsequent layers. They should be made of soft enough metal so as not to damage cutting edges tool used for further processing of the spar.
Layers of plywood are generously moistened using a roller or brush with ED-5 resin. Then a strip of fiberglass is sequentially applied to the plywood, which is smoothed by hand and a wooden smoother until resin appears on its surface. After this, a layer of plywood is placed on the fabric, which is first coated with resin on the side that will lie on the fiberglass. The spar assembled in this way is covered with tracing paper, and a rail measuring 3100x90x40 mm is placed on it. Between the lath and the pile, clamps located at a distance of 250 mm from each other along the entire length of the lath are used to compress the assembled package until its thickness is equal to the upper edges of the mounting plates. Excess resin must be removed before it hardens.
The spar blank is removed from the stock after 2-3 days and processed to a width of 70 mm in the profile part, 90 mm in the butt part, and a length between the ends of 3100 mm. Necessary Requirement, which should be observed at this stage, is to ensure the straightness of the spar surface, which forms the leading edge of the blade in the process of further profiling. The surface to which the ribs and foam core will be glued must also be fairly straight. It should be processed with a plane and always with a carbide knife or, in extreme cases, quarry files. All four longitudinal surfaces of the spar blank must be mutually perpendicular.
PRELIMINARY PROFILING
The marking of the spar blank is done as follows. It is placed on the slipway and lines are drawn on the end, front and rear planes, spaced from the surface of the slipway at a distance of 8 mm (~Un max). At the end end, in addition, using a template (Fig. 4), the full profile of the blade is drawn on a scale of 1:1. Special precision is not required in the manufacture of this auxiliary template. A chord line is drawn on the outside of the template and two holes with a diameter of 6 mm are drilled on it at the toe of the profile and at a point at a distance of 65 mm from it. Looking through the holes, combine the chord line of the template with the line drawn at the end face of the spar to draw a line on it that defines the profiling boundary. To avoid shifts, the template is attached to the end with thin nails, for which holes randomly located along their diameter are drilled into it.
The processing of the spars along the profile is carried out with a simple plane (rough) and a flat bastard file. In the longitudinal direction it is controlled with a ruler. Having completed the processing, the ribs are glued to the rear surface of the spar. The accuracy of their installation is ensured by the fact that during manufacturing a chord line is applied to them, which coincides with the chord line marked on the rear plane of the spar blank, as well as by visual verification of the straightness of their location relative to the auxiliary template. It is again attached to the end end for this purpose. The ribs are placed at a distance of 250 mm from each other, with the first one being placed at the very beginning of the spar profile or at a distance of 650 mm from the end of its butt part.
ASSEMBLY AND PROCESSING OF THE BLADE
After the resin has hardened, foam plastic plates are glued between the ribs, corresponding to the profile of the rear part of the blade, and cuts are made along the protruding ends of the ribs in the rail forming the trailing edge. The latter is glued to
resin to ribs and foam plates.
Next, the foam plates are rough processed, the curvature of which is adjusted to the curvature of the ribs, and excess wood is also removed from the lath to form a trailing edge with some allowance for subsequent precise processing according to the main template (Fig. 5).
The base template is first made with an allowance of 0.2 - 0.25 mm for the values of UV and Un indicated in the template in order to obtain a profile of a smaller than final size for gluing with fiberglass.
When processing a blade using the main template, its lower surface is taken as the base. For this purpose, the straightness of its generatrix is verified with a straight edge at a distance Xn = 71.8 mm, where Un = 8.1 mm. Straightness can be considered sufficient if there is a gap of no more than 0.2 mm in the middle of a 1 m long ruler.
Then guide rails made of hardwood or duralumin 8.1 mm high are attached to the long sides of a well-aligned duralumin plate measuring 500x226x6 mm. The distance between them for the upper half of the main template should be equal to the width of the blade, or 180 mm. The latter is laid on a slipway on 3 - 4 pads, the thickness of which is equal to the thickness of the device plate, and pressed with clamps. Thanks to this, the straightened plate can move between the slipway and the lower surface of the blade along its entire length in a straight plane, which ensures the consistency of the thickness of the blade and compliance of its surface with a given profile.
The upper surface of the blade can be considered processed if the upper half of the template moves along its entire length without a gap along the profile and in places where the template contacts the guides. The lower surface of the blade is checked with a fully assembled template, both halves of which are rigidly connected together. The upper and lower surfaces are profiled using bastard files with coarse and medium notches, and depressions and irregularities are sealed according to a template using ED-5 resin putty mixed with wood flour, and filed again according to the template.
BLADE Wrapping
The next operation is to paste the profile and butt parts of the blades with fiberglass cloth 0.1 mm thick in two layers on ED-5 resin. Each layer is a continuous strip of fiberglass, which is applied with its middle to the leading edge of the blade. The main requirement that must be observed in this case is that the excess resin, after the fabric is well saturated with it, must be carefully squeezed out using a wooden trowel in the transverse direction from the front edge to the back, so that no resin forms under the fabric. air bubbles. The fabric should not be tucked or wrinkled anywhere to avoid unnecessary thickening.
Having pasted over the blades, they are cleaned sandpaper, and the trailing edge is brought to a thickness close to the final one. The profile of the spar toe is also checked. For now, this is done using a basic template with some allowances, as indicated above, to ensure the quality of the profiling of the upper and lower surfaces.
The main template is brought to the required size and with its help the final adjustment of the profile is made using putty, and the lower surface of the blade is again taken as a basis, for which the straightness of its generatrix is again checked using a pattern ruler at a distance Xn = 71.8 mm from the toe. Having made sure of its straightness, the blade is placed on the slipway with the bottom surface down on pads 42 mm high (this value is the rounded difference between the height of the lower half of the template and Un = 8.1 mm). One of the linings lies under the butt part of the blade, which in this place is pressed against the slipway with a clamp, the rest along the blade at arbitrary distances from each other. After this, the upper surface of the blade is washed with acetone or solvent and coated along the entire length thin layer putty made from ED-5 resin and tooth powder of such thickness that it is easily distributed on the surface and does not flow along the curvature of the profile (the consistency of thick sour cream). The firmly fastened main template slowly and evenly moves along the blade with a chamfer forward along the movement so that its edge always rests on the horizontal surface of the slipway. By removing excess putty from the convex areas of the profile and leaving the required amount in the depressions, the template thus ensures that the profile is finished. If it turns out that the depressions in some places have not been filled, then this operation is repeated after applying a thicker layer of putty to them. Excess putty must be removed periodically when it begins to hang over the leading and trailing edges of the blade.
When performing this operation, it is important to move the template without distortions and perpendicular to the longitudinal axis of the blade, moving it non-stop to avoid uneven surfaces of the blade. Having allowed the putty to reach full hardness and smoothed it lightly with sandpaper, the final putty operation is repeated on the lower surface, using pads 37 mm high.
BLADE FINISH
Having made the blades, they are treated with medium-grit sandpaper, turning Special attention to form the profile toe, wash with acetone or solvent and cover with primer No. 138, except for the place where the trimmer is attached (Fig. 6). Then all irregularities are sealed with nitro putty, making sure that unnecessary thickening does not form on the profiled surfaces.
The final finishing work, which consists of carefully removing excess putty with waterproof sandpaper of different grain sizes, is carried out in accordance with the advancement of the closed template along the surfaces of the blade without excessive rolling and gaps (no more than 0.1 mm).
After pasting the blades with fiberglass cloth 0.1 mm thick and before covering them with soil, oak or ash plates measuring 400x90x6 mm are glued onto the butt part of the blades from above and below using ED-5 resin, which are planed so that the blades acquire an installation angle enclosed between the chord and horizontal plane and equal to 3°. It is checked using a simple template (Fig. 7) relative to the front surface of the butt, as well as by checking the parallelism of the resulting surfaces below and above the butt.
This completes the formation of the butt of the blade, and it is covered with 0.3 mm fiberglass on ED-5 resin to make the blade airtight. The finished blade, except the butt, is painted with nitro enamel and polished.
Read the following issues of the magazine for advice on determining the actual position of the center of gravity of the blades, their balancing and mating with the hub.
ASSEMBLY AND ADJUSTMENT
The previous issue of the magazine described in detail the technological process of manufacturing the main rotor blades of a gyroplane.
The next stage is balancing the blades along the chord, assembling and balancing the main rotor along the radius of the blades. The smooth operation of the main rotor depends on the accuracy of installation of the latter, otherwise increased unwanted vibrations will occur. Therefore, the assembly must be taken very seriously - do not rush, do not start work until everything is selected necessary tool, fixtures and not prepared workplace. When balancing and assembling, you must constantly monitor your actions - it is better to measure seven times than to fall even once from a low height.
The process of balancing blades along the chord in this case comes down to determining the position of the center of gravity of the blade element.
The main purpose behind the need to balance the blade along the chord is to reduce the tendency for flutter-type oscillations to occur. Although the described machine is unlikely to experience these vibrations, you need to remember about them, and when adjusting, every effort should be made to ensure that the center of gravity of the blade is within 20 - 24% of the chord from the tip of the profile. The NACA-23012 blade profile has a very small movement of the center of pressure (CP is the point of application of all aerodynamic forces acting on the blade in flight), which is within the same limits as the CG. This makes it possible to combine the CG and CP lines, which practically means the absence of a pair of forces causing twisting of the main rotor blade.
The proposed blade design ensures the required position of the CG and CP, provided they are manufactured strictly according to the drawing. But even with the most careful selection of materials and adherence to technology, weight discrepancies can arise, which is why balancing work is carried out.
Define (with some permissible errors) the CG position of the manufactured blade can be achieved by making the blades with an allowance at the ends of 50-100 mm. After the final filing, the allowance is cut off, the tip is placed on the blade, and the cut element is balanced.
1 – corner limiter (D16T); 2 – main rotor axis (30ХГСА); 3 – lower plate of the bushing (D16T, s6); 4 – bushing truss (D16T); 5 – main hinge axis (30ХГСА); 6 – bushing (tin bronze); 7 – washer Ø20 – 10, 5 – 0.2 (steel 45); 8 – bearing housing (D16T); 9 – hole for the cotter pin; 10 – bearing housing cover. (D16T); 11 – castle nut M18; 12 – washer Ø26 – 18, 5 – 2 (steel 20); 13 - cover fastening screw M4; 14 – angular contact bearing; 15 – radial-spherical bearing No. 61204; 16 – blade fastening bolt (30ХГСА); 17 – blade cover (s3, 30ХГСА); 18 – washer Ø14 – 10 – 1.5 (steel 20); 19 – self-locking nut M10; 20 – M8 screw; 21 – bougie (Ø61, L = 200, D16T); 22 – pylon (pipe Ø65×2, L=1375, linden)
A blade element is placed on a triangular, horizontally located prism with its lower surface (Fig. 1). Its section plane along the chord must be strictly perpendicular to the edge of the prism. By moving the blade element along the chord, its balance is achieved and the distance at the toe of the profile to the edge of the prism is measured. This distance should be 20 - 24% of the chord length. If the CG goes beyond this maximum limit, an anti-flutter weight of such weight will need to be hung on the tip of the profile at the tip of the blade so that the CG moves forward by the required amount.
The butt of the blade is reinforced with linings, which are steel plates 3 mm thick (Fig. 2). They are attached to the butt of the blade with pistons with a diameter of 8 mm and flush rivets using any glue: BF-2, PU-2, ED-5 or ED-6. Before installing the linings, the butt of the blade is cleaned with coarse sandpaper, and the lining itself is sandblasted. The surfaces of the parts to be glued, that is, the butt of the blade, linings, holes for the pistons and the pistons themselves, are degreased and thoroughly lubricated with glue. Then the caps are riveted and rivets are placed (4 pieces for each pad). After this operation, the blades are ready for marking for installation on the hub.
The main rotor of a gyroplane (Fig. 3) consists of two blades, a hub, a rotor axis with rolling bearings, a bearing housing for a horizontal hinge and a limiter for the deflection angles of the main rotor axis.
The bushing consists of two parts: a U-shaped truss and a bottom plate (Fig. 4). It is advisable to make the truss from a forging. When making it from rolled products, special attention must be paid to ensure that the direction of the rolled products is necessarily parallel to the longitudinal axis of the truss. The same direction of rolling should be on the bottom plate, which is made from a sheet of duralumin grade D16T 6 mm thick.
The processing of the truss is carried out according to the operation in the following order: first, the workpiece is milled, leaving an allowance of 1.5 mm per side, then the truss is subjected heat treatment(hardening and aging), after which final milling is carried out according to the drawing (see Fig. 4). Then, using a scraper and sandpaper on the farm, all transverse marks are removed and a longitudinal stroke is applied.
The axis (Fig. 5) is mounted on the pylon on two mutually perpendicular axes, which allow it to deviate from the vertical at specified angles.
Two rolling bearings are mounted on the upper part of the axle: the lower one is radial No. 61204, the upper one is angular contact No. 36204. The bearings are enclosed in a housing (Fig. 6), which with its lower inner side absorbs the entire load from the weight of the gyroplane in flight. When manufacturing the body, special attention must be paid to the processing of the interface between the side and the cylindrical part. Undercuts and risks at the interface are unacceptable. In the upper part, the bearing housing has two ears into which bronze bushings are pressed. The holes in the bushings are machined with reamers after they are pressed in. The axis of the bushings must pass through the axis of rotation of the housing strictly perpendicular to it. Through the holes in the ears of the bearing housing and bushings, which are pressed into the cheeks of the truss, a bolt passes (Fig. 7), which is a horizontal hinge of the main rotor of the gyroplane, relative to the axis of which the blades make flapping movements.
The angle of deviation of the axis and, accordingly, the change in the position of the plane of rotation of the disk is limited by a plate mounted on the pylon (Fig. 8). This plate does not allow the rotor to deviate beyond the permissible angles that ensure pitch and roll control of the gyroplane.
B. BARKOVSKY, Y. RYSYUK
Who in childhood did not dream of becoming a pilot, conqueror of the fifth ocean of air! Many romantic natures do not give up this dream even in adulthood. And they can implement it: currently there is a wide variety of aircraft that even amateur pilots can fly. But, unfortunately, if such devices are factory-made and offered for sale, their cost is so high that they are practically inaccessible to most.
However, there is another way - self-production reliable and relatively simple aircraft. For example, a gyroplane. This article offers a description of just such a design that almost any person involved in technical creativity can do. To build a gyroplane you do not need expensive materials and special conditions- there is enough space directly in the apartment, as long as household members and neighbors do not object. And only a limited number of structural parts require turning.
For an enthusiast who has decided to independently manufacture the proposed aircraft, I would recommend assembling a gyrocopter-glider at first. It is lifted into the air by a tow rope attached to a moving vehicle. The flight altitude depends on the length of the cable and can exceed 50 meters. After rising to such a height and the pilot releasing the cable, the gyroplane is able to continue flight, gradually descending at an angle of approximately 15 degrees to the horizon. Such planning will allow the pilot to develop the control skills he needs in free flights. And he will be able to start working on them if he installs an engine with a pusher propeller on the gyroplane. In this case, no changes to the design of the aircraft will be required. With an engine, the gyroplane will be able to reach speeds of up to 150 km/h and rise to a height of several thousand meters. But oh power plant and its placement on the aircraft later, in a separate publication.
So, a gyroplane. It is based on three duralumin power elements: the keel and axial beams and the mast. At the front, on the keel beam, there is a steerable nose wheel (from a sports microcar-kart), equipped with braking device, and at the ends of the axle beam there are side wheels (from a scooter). By the way, instead of wheels, you can install two floats if you plan to fly in tow behind a boat.
There, at the front end of the keel beam, a truss is installed - a triangular structure riveted from duralumin corners and reinforced with rectangular sheet overlays. It is designed to attach a tow hook, which is designed so that the pilot, by pulling the cord, can unhook from the tow rope at any time. Aeronautical instruments are also installed on the truss - simple homemade indicators of airspeed and lateral drift, and under the truss there is a pedal assembly with cable wiring to the rudder. At the opposite end of this beam there is an empennage: horizontal (stabilizer) and vertical (keel with rudder), as well as a safety tail wheel. All pictures enlarge when clicked
Gyrocopter layout:
1 - farm; 2 - towing hook; 3 - clip for fastening the towing hook (D16T); 4 - airspeed indicator; 5 - lateral drift indicator; 6 - stretch ( steel rope 02); 7 - control handle; 8 - main rotor blade; 9 - main rotor rotor head; 10 - rotor head bracket (D16T, sheet s4, 2 pcs.); 11 - mast (D16T, pipe 50x50x3); 12 - seat back mounting bracket (aluminum, sheet s3, 2 pcs.); 13 - seat back; 14 - “aircraft” version of the control stick; 15 - seat frame; 16 - bracket for the “aircraft” control stick; 17 - seat mounting bracket; 18.25 - control cable rollers (4 pcs.); 19 - strut (D16T, corner 30x30, 2 pcs.); 20 - mast mounting bracket (D16T, sheet s4, 2 pcs.); 21 - upper brace (steel, corner 30x30, 2 pcs.); 22 - horizontal tail; 23 - vertical tail; 24 - tail wheel; 26 - left branch of control wiring (cable 02); 27 - axial beam (D16T, pipe 50x50x3); 28 - side wheel axle mounting unit; 29 - lower brace (steel, corner 30x30.2 pcs.); 30 - seat support (D16T, corner 25x25, 2 pcs.); 31 - brake device; 32 - pedal assembly; 33 - keel beam (D16T, pipe 50x50x3)
In the middle of the keel beam there is a mast and a pilot's workplace - a seat with car seat belts. The mast is attached to the beam with two duralumin plate brackets at a slight angle to the vertical back and serves as the basis for the rotor of a two-bladed carrier propeller. The rotor mechanism is also connected to the mast by similar plate brackets. The screw rotates freely and unwinds due to the oncoming air flow. The rotor axis can be tilted in any direction using a handle, conventionally called a “delta handle,” with which the pilot adjusts the position of the gyroplane in space. This control system is the simplest, but differs from the standard one used on the vast majority of aircraft in that when the handle moves away from you, the gyroplane does not descend, but, on the contrary, gains altitude.
If desired, it is also possible to install an “aircraft” control stick (it is shown in dashed lines in the figure). The design naturally becomes more complicated. However, it is necessary to choose the type of control before building the gyroplane. The modification is unacceptable, since the piloting skills acquired with a “glitch” stick may give an undesirable result when switching to an “airplane” stick.
In addition, when moving on the ground, the pilot controls the nose wheel with his feet, and after takeoff, when the tail becomes effective as speed increases, he also controls the nose wheel with his feet and rudder. In the first case, he steers by alternately pressing his right or left foot on the corresponding shoulder of the crossbar of the brake device on the wheel; in the second - to one or another pedal connected by cable wiring to the rudder.
The braking device is used during the run when landing on the runway. It is also not particularly difficult. The pilot presses the clutch with his heels (or simply - wooden board) to the tire of the wheel, causing them to rub against each other and thereby dampen the speed of the aircraft. As simple and cheap as possible!
The low weight and dimensions of the gyroplane allow it to be transported even on the roof passenger car. The propeller blades are then disconnected. They are installed at their workplace immediately before the flight.
FRAME MANUFACTURING
As already mentioned, the basis of the gyroplane frame is the keel and axial beams and the mast. They are made of duralumin pipe with a square section of 50x50 mm with a wall thickness of 3 mm. Similar profiles are used in the construction of windows, doors, shop windows and other building elements. It is possible to use box beams made of duralumin corners connected by argon-arc welding. The best material option is D16T.
All holes in the beams were marked so that the drill only touched the inner walls without damaging them. The diameter of the drill was selected so that the MB bolts fit into the holes as tightly as possible. The work was carried out exclusively electric drill- using a manual one for these purposes is undesirable.
Most of the holes in the frame parts are coordinated in the drawings. However, many of them were drilled in place, as, for example, in plate brackets connecting keel beam with a mast. First, the right bracket, screwed to the keel beam, was drilled through the holes in the base of the mast pressed to it, then the left bracket was screwed on and also drilled, but through the finished holes of the right bracket and mast.
By the way, in the layout drawing it is noticeable that the mast is slightly tilted back (for this purpose, its base was beveled before installation). This is done so that the main rotor blades have an initial angle of attack of 9° on the ground. Then, even at a relatively low towing speed, a lifting force appears on them, the propeller begins to rotate, lifting the gyroplane into the air.
The axial beam is located across the keel and is attached to it with four Mb bolts with locked split nuts. In addition, the beams are connected by four angle steel braces for greater rigidity. Wheel axles (suitable for a scooter or motorcycle) are attached to the ends of the axle beam with paired clips. The wheels, as already mentioned, are scooter wheels, with bearings sealed to prevent dust and dirt from getting into them with caps from aerosol cans.
The frame and back of the seat are made of duralumin pipes (parts from children's cots or strollers are very suitable for this). At the front, the frame is attached to the keel beam with two duralumin corners 25x25 mm, and at the back - to the mast with a bracket made of steel corner 30x30 mm. The back, in turn, is screwed to the seat frame and also to the mast.
The seat frame is fitted with rings cut from the rubber inner tube of a truck wheel. A foam pillow covered with durable fabric is placed on top of them and tied with ribbons. A cover made of the same fabric is placed on the back.
The front landing gear is a sheet steel fork with a kart wheel that rotates around a vertical axis. The axis is a short M12 bolt inserted into the hole in the sole (a rectangle made of steel sheet), which is attached to the keel beam from below with four Mb bolts. An additional round hole is cut in the keel beam for the head of the axle bolt.
A braking device is hingedly suspended from the sides to the fork stays of the nose wheel. It is assembled from a tubular cross member, two corner stringers and a wooden clutch. Let me remind you that the protruding ends of the crossbar allow the pilot to turn the steering wheel with his feet.
In the initial position, the device is held by two cylindrical tension springs, hooked to the brackets on the nose of the keel beam, and by a cable passed through the holes in the friction board. The springs are adjusted so that, in the absence of pilot control actions, the wheel is in the plane of symmetry of the gyroplane.
The pedal unit for controlling the aerodynamic rudder in the air is also quite simple. Both pedals, together with the parts riveted to them, are connected by hinge bolts to a pipe that is screwed to the angle on the keel beam. At the top of the pedals are attached sections of cable that stretch to the rudder hogs on the keel. The control wiring has four guide rollers, the design of which prevents the cables from falling out of them. The tension of the cables is maintained by coil springs attached to the pedals and a plate bracket on the keel beam. The springs are adjusted so that the rudder is in the neutral position.
The design of the truss is described in some detail above. Therefore, I will focus on what is mounted on the farm - on homemade aeronautical instruments, or rather, on one of them - the airspeed indicator. It's open at the top glass tube, in which a light plastic ball is placed. At the bottom it has a calibrated hole directed towards the flight of the gyroplane. The oncoming air flow causes the ball to rise in the tube, and its position determines the air speed. You can calibrate the indicator by placing it out the window of a moving car. It is important to accurately plot the speed values in the range from 0 to 60 km/h, since these are the values that are important during takeoff and landing.
The horizontal tail is made of sheet duralumin 3 mm thick. The tail has two slots for duralumin corner struts to support the mast. At the points where the empennage is bolted to the keel beam, pads are riveted to the stabilizer to increase the rigidity of the connection.
The vertical tail is more complicated. It consists of a fin and rudder cut from multi-layer plywood: the first from 10 mm, the second from 6 mm. The individual edges of these parts are edged with thin steel tape. The keel and rudder are connected to each other by three card loops (on the left side).
Two counterweights weighing 350 g each are attached to the aerodynamic rudder horn with a through bolt MB (they are needed to eliminate the flutter phenomenon).
The trimmer on the rear edge of the handlebar is made of soft sheet aluminum. By bending this plate to the right or left, you can adjust the accuracy of the steering wheel.
On both sides of the steering wheel there are screwed hogs, curved from a steel sheet. The heading control wiring cables are attached to them.
The vertical tail is attached to the keel beam on the right and for greater rigidity is reinforced with two brackets made of duralumin angle 25x25 mm.
At the end of the keel beam there is a tail wheel (from roller skates). It protects the vertical tail from damage if the gyroplane accidentally tips over on its tail, as well as during takeoff or landing with the nose too high.
RECOMMENDATION:
preliminary check of the gyroplane on the ground
You have assembled a gyroplane. Before you start making the rotor, check how the ready-made mechanisms work. It is best to do this at the site from which the gyroplane is supposed to fly.
Sit on the seat and make sure you are sitting comfortably and can reach the pedals with your feet. If necessary, place an additional pillow under your back. Jump on the seat - the cushion should not allow your body to touch the frame.
Tilt the nose wheel with your feet and watch the springs return it to the neutral position. Make sure that in this position the springs are not too tight, but not too loose. There should be no play in all connections.
Attach the gyroplane with a cable no more than ten meters long to the car and taxi at a speed of no more than 20 km/h. Warn the driver not to suddenly brake or reduce speed suddenly.
Remove your feet from the braking bar and see if the gyroplane maintains a straight line. Otherwise, adjust the spring tension. Learn to automatically find with your hand the cord for opening the hook and releasing the tow rope.
The rotor rotor, located at the top of the mast, is the most complex knot in the design of a gyroplane. The life of the pilot, no exaggeration, depends on the quality of workmanship, precision of assembly and error-free operation. The main materials for the parts of this assembly are D16T duralumin and ZOKHGSA steel (all duralumin parts are anodized, steel parts are cadmium-plated).
The rotor housing is perhaps the most important part, since in flight it is on the housing lugs that the entire structure of the gyroplane hangs. The housing itself houses two bearings - radial and angular contact, generously lubricated with grease. The housing with bearings rotates on the rotor axis. At the top of the axle there is a cottered slotted nut M20x1.5 (it should be noted that there are no simple nuts in the design of the gyroplane: the most important of them are cottered, the rest are self-locking). A blind cover hiding the axle nut protects the bearings from dust and moisture penetrating into them.
At the bottom, the rotor axis is fixedly connected to the control stick of the gyroplane. By moving the handle, you can change the position of the rotor in space, since the articulated connection of the axle with the axle and the axle with its body allows the deflection of the axis within the limits dictated by the diameter of the limiter hole.
The rotor is bolted to the top of the mast using two plate brackets.
RECOMMENDATION:
checking the alignment of the gyroplane
When the rotor head is ready and installed on the gyroplane, it is necessary to check the alignment of the gyroplane. Insert a bolt into the ears of the rotor housing, which will secure the rotor head with the main rotor blades, and hang the gyroplane by this bolt, for example, on a strong tree branch.
Sit on the seat and grasp the control handle. Keep it neutral. Have an assistant determine the position of the gyroplane mast. It should be tilted forward at an angle within 2-6° (ideally 4°). This check, usually called weight balancing, must be repeated whenever the weight of the pilot or gyroplane changes. In all cases, you cannot fly without such a check.
If the specified angle is outside the permitted range, then either move the pilot or add a small amount of ballast to the tail. But if it happened significant change pilot's mass (it exceeded 100 kg) or an engine is installed on the gyroplane, it is necessary to make new, thicker plate brackets that hold the rotor at the top of the mast.
The main rotor blades are completely identical, so it is enough to describe the manufacturing process of only one of them.
Along the entire working length of the blade, its cross-sections are the same; no twisting or changing of geometric parameters is provided. This greatly simplifies things.
The best material for the front part of the blade is delta wood, which was used in aviation and maritime affairs. If you don’t have it, you can make an analogue yourself by gluing it with epoxy resin thin sheets plywood with fiberglass spacers. Aviation plywood 1 mm thick is suitable for such a substitute. Since plywood sheets of the length required for the manufacture of blades are not produced, it is possible to glue together plywood strips cut to length. The joints in adjacent sheets should not be located one above the other, they must be spaced apart.
It is better to glue on a flat surface, placing plastic film, to which epoxy glue does not stick. You need to dial a total thickness of 20 mm. After applying the glue, the entire “pie” of the future blade should be pressed down with some long and even object with a weight and left to dry completely for a day. In terms of its mechanical properties, the resulting composition is no worse than real delta wood.
The specified profile of the leading edge (toe) of the spar is obtained using a template in the following way. Along the entire span of the spar, with a pitch of 150-200 mm, grooves are made in the leading edge until the template fits completely into the spar. The wood between the grooves is planed to make a ruler.
In the rear edges of the spar, using a planer (you can use scrapers), “quarters” 10 mm wide and 1 mm deep were selected under the plywood sheathing. The sheet of the lower skin (flush with the spar) is glued with epoxy resin, and to it and the spar are sheets of PS-1 foam plastic, which are pre-planed to a height of 20 mm. The foam layer is given the required shape according to the template of the top of the blade profile. A pine strip was used as the trailing edge. The top skin was glued last: it was enough to press it with clamps to the “quarter” of the spar and the trailing edge - and the sheet of plywood itself took the desired shape (the trailing edge of the blade should be slightly bent upward, as shown in the figure).
Each blade has a 100 g weight mounted in a fairing on the leading edge and a folding trimmer on the trailing edge. In the butt part of the blade, steel linings are riveted, through which holes are drilled in the spar to attach the blade to the rotor head.
RECOMMENDATION:
balancing and tuning of blades
"After fabrication and painting, the blades need to be adjusted. Give this operation the utmost attention. Keep in mind that the cleaner and smoother the surfaces of the blades, the more lift they will create, and the gyroplane will be able to take off at a lower speed.
Attach the blades to the rotor head and check the balancing. If one of the blades turns out to be heavier and its end drops lower, then drill out part of its lead weight, ensuring that the blades are even. If this operation does not produce results (no more than 50 g can be removed), then drill several shallow holes in the thickest section of the light blade profile and fill them with lead.
Since the tips of the blades rotate at a peripheral speed of about 500 km/h, it is very important that they rotate in the same plane. Stick two different colored ones on the leading edges at the very end of the blades. plastic tapes. On a windy day, choose a place where the wind is constantly blowing at a speed of about 20-30 km/h (check with an airspeed indicator) and place the gyroplane against the wind. Tie it with a five-meter rope to a stump or stake firmly driven into the ground.
Sit on the seat, strap yourself in and, together with the gyroplane, back away so that the rope is taut. Holding the control handle with your left hand, place the rotor in a horizontal position, and with your right hand, spin the blades as hard as you can. Your assistant should watch from the side the rotation of the ends of the rotor.
Gradually tilt the rotor back and let it spin in the wind to a higher speed. If the multi-colored stripes rotate in the same plane, the blades have the same pitch. If you feel the glider shaking or an assistant shows that the blades are not rotating in the same plane, then immediately unload the rotor by moving it to a horizontal position or even tilting it forward. By bending the trimmers at a slight angle down or up, achieve the correct rotation of the blades.
As the rotor speed increases, the glider will rock and the front wheel will rise. In this case, the rotor will be tilted back, which will lead to even more intense spinning. Place your feet on the ground and control the position of the gyroplane in space. If you feel that it is taking off, immediately unload the rotor by pulling the control stick towards you. Having practiced this way, you will soon be ready for your first flight.
DIY gyroplane video
FLIGHT PRACTICE
Since not only the pilot, but also the driver of the car participates in the flight, there must be complete interaction between them. It is best if, in addition to the driver, there is another person in the car who can monitor the flight and receive all the pilot’s signals (decrease or increase in speed, etc.).
Before flights, check the technical condition of the gyroplane again. At first, use a relatively short tow rope no more than 20 m long. Be sure to warn the driver that they should accelerate smoothly and never brake sharply.
Position the gyroplane against the wind. Spin the rotor with your right hand and wait until it begins to gain speed due to the air pressure. If the wind is light, then give the driver the command to move at a speed of 10-15 km/h using the airspeed indicator. Continue to help the rotor with your hand as long as you can.
As you accelerate, tilt the rotor all the way back and give the driver a signal to increase the speed to 20-30 km/h. While steering the nose wheel, follow the vehicle in a straight line. When that wheel leaves the ground, move your feet to the pedals. By manipulating the control stick, maintain the position of the gyroplane so that it moves only on the side wheels, without touching the ground with either the nose or tail. Wait for the increased airspeed to lift the gyroplane into the air in this position. Adjust the flight altitude by longitudinal movements of the control stick (the rudder is not effective, since the glider is towed on a cable). During flight, do not allow any slack in the tow rope. Do not make turns at high speed.
Before landing, align yourself behind the vehicle until it reaches the end of the runway. Smoothly tilt the rotor forward and fly at an altitude of about a meter. Maintain this position with small “twitches” of the control handle. (In general, unlike controlling an airplane, on a gyroplane the movements of the sticks should not be smooth, but sharp, literally jerky.)
Signal the driver to slow down. When it does this, tilt the rotor all the way back. The rear wheel of the gyroplane should touch the ground first. Keep the rotor tilted back to prevent slack in the tow rope. When you stop, let the car turn around and move with it to the starting point. Keep the rotor positioned so that it continues to rotate. If there are no more flights, then place the rotor horizontally and, when the rotation speed decreases, stop it by hand. Never leave your seat while the rotor is spinning, otherwise the gyroplane may fly away without you.
Gradually, as you master your piloting technique, increase the length of the tow rope to one hundred meters and rise to a greater height.
The last stage of mastering the flight on a gyroplane will be free flight after uncoupling from the tow rope. Do not under any circumstances reduce the airspeed below 30 km/h in this mode!
From a height of 60 m, the free flight range can reach 300 m. Learn to make turns and rise to great heights. If you start from a hill, the flight range can be kilometers.
How to make a gyroplane with your own hands? This question was most likely asked by those people who really love or want to fly. It is worth noting that perhaps not everyone has heard of this device, since it is not very common. They were widely used only until helicopters were invented in the form in which they exist now. From the moment such aircraft models took to the skies, gyroplanes immediately lost their relevance.
How to build a gyroplane with your own hands? Blueprints
Creating such an aircraft will not be difficult for anyone who is interested in technical creativity. Special tools or expensive ones building materials won't be needed either. The space that will have to be allocated for assembly is minimal. It’s worth adding right away that assembling a gyroplane with your own hands will save a huge amount of money, since buying a factory model will require huge financial costs. Before you begin the process of modeling this device, you need to make sure you have all the tools and materials at hand. The second step is the creation of a drawing, without which it is not possible to assemble a standing structure.
Basic design
It’s worth saying right away that building a gyroplane with your own hands is quite simple if it’s a glider. With other models it will be somewhat more difficult.
So, to start work you will need to have three duralumin power elements among the materials. One of them will serve as the keel of the structure, the second will act as an axial beam, and the third will serve as a mast. A steerable nose wheel can be immediately attached to the keel beam, which must be equipped with a braking device. The ends of the axial force element must also be equipped with wheels. You can use small parts from a scooter. Important point: if you assemble a gyroplane with your own hands for flying behind a boat in tow, then the wheels are replaced with controlled floats.
Farm installation
Another main element is the farm. This part is also mounted on the front end of the keel beam. This device is a triangular structure, which is riveted from three duralumin corners, and then reinforced with sheet overlays. The purpose of this design is to secure the towbar. The construction of a do-it-yourself gyroplane with a truss must be made in such a way that the pilot, by pulling the cord, can unhook from the tow rope at any time. In addition, the truss is also necessary so that the simplest air navigation instruments can be installed on it. These include a flight speed tracking device, as well as a lateral drift mechanism.
Another main element is the installation of the pedal assembly, which is installed directly under the truss. This part must have a cable connection to the aircraft control rudder.
Frame for the unit
When assembling a gyroplane with your own hands, it is very important to pay due attention to its frame.
As mentioned earlier, this will require three duralumin pipes. These parts should have a cross-section of 50x50 mm, and the thickness of the pipe walls should be 3 mm. Similar elements are often used when installing windows or doors. Since it will be necessary to drill holes in these pipes, you need to remember an important rule: when carrying out work, the drill should not damage the inner wall of the element, it should only touch it and no more. If we talk about choosing a diameter, then it should be selected so that the MB type bolt can fit as tightly as possible into the resulting hole.
One more important note. When drawing up a drawing of a gyroplane with your own hands, you need to take into account one nuance. When assembling the apparatus, the mast should be tilted back slightly. The angle of inclination of this part is approximately 9 degrees. When drawing up a drawing, this point must be taken into account so as not to forget later. The main purpose of this action is to create an angle of attack of the gyroplane blades of 9 degrees even when it is just standing on the ground.
Assembly
Assembling the gyroplane frame with your own hands continues with the need to secure the axial beam. It is attached to the keel across. To securely fasten one base element to another, you need to use 4 MB bolts, and also add locked nuts to them. In addition to this fastening, it is necessary to create additional rigidity of the structure. To do this, use four braces that connect the two parts. The braces must be made of angle steel. At the ends of the axle beam, as mentioned earlier, it is necessary to secure the wheel axles. To do this, you can use paired clips.
The next step in assembling a gyroplane with your own hands is to make the frame and seat back. In order to assemble this small structure, it is best to also use duralumin pipes. Parts from children's cots or strollers are great for assembling the frame. To fasten the seat frame at the front, two duralumin corners with dimensions of 25x25 mm are used, and at the back it is attached to the mast using a bracket made of a steel corner 30x30 mm.
Checking the gyroplane
After the frame is ready, the seat is assembled and attached, the truss is ready, navigation devices and other equipment are installed important elements gyroplane, you need to check how the finished design works. This must be done before the rotor is installed and designed. Important note: it is necessary to check the performance of the aircraft at the site from which further flights are planned.