gjpauler

Its not about that I expect that teenagers will play with dolls (they do play, but thats already living doll...). But driver is a "functional part" of a vehicle, which should be fit to vehicles "user interface", and it is a challenge. Thats why I did not care that my figures faces are damn nasty. They fulfill a function and can be reused through their very last part in any other Technic model.

Visit My Lego Helicopters Blog In many major Lego-related sites we can read complaints about that Lego Technic figures were discontinued by Lego since mid-90s of last century. Even reasons of discountinuation are not very clear: - Some guys say that Technic Figure contained too many joints, and it was too expensive to manufacture compared to demand - Others say that Technic Figures were too big, or too small, or they were not very good looking because of the nasty holes in the leg part, which were also in quite a pointless position - In my point of view, Technic Figures were simply victims of a bureaucratic manufacturing cost cut: if figures are added to Technic sets, their scale is tied to figures' scale=1:18. Without adding figure, large Technic sets (Bulldozer, Unimog, Large rescue helicopter, Truck, Crane, etc.) can be scaled down from 1:18 to about 1:22 (1:36 is the minifig scale). At first sight, it does not seem too much, but average material reqirement of a model changes roughly with third power of linear size (to put it simply - twice as big model requires almost eight times more bricks). So it means serious brick count - and cost reduction, which can make reasonable profit even at reasonable retail prices. But then, why fourty-some years old Adult Friends Of Lego cry after authentic technic figures like babies after their lost puppet? 1. Because in professional, high-end Lego Technic building, ergonomic placement of drivers in cocpits, and realistic working controls of a vehicle poses serious modelling challenge. 2. Some types of machines (eg. supersport cars, motorbikes) just look good with fancy girls (try to imagine a motorcycle with a minifig girl posing it... eeee... epic fail) 3. Some types of machines just does not look good with fancy girls, but with handsome guys (eg. heavy battlefield helicopters) As there is no hope that Lego will do something in this story, I decided to design replacement of technic figures along the following lines: GOAL1: Reasonable, payable scale: You can create mighty warriors/ robots/transformers from bionicle in scale 1:10..1:6. Thats impressive. But just imagine that once the mighty warriors get tired of walking, and you need a simple Armoured Personell Carrier (APC). In scale 1:10, that will cost you about 2200 bricks, baby... (war is an expensive thing, although). Therefore, the big challenge is to do something fancy in 1:18..1:20 scale. Technic Figure was 12 studs tall, 4 studs wide, and 1 stud tchick, forming a thin, feminine type of guy. The reason is obvious: it could fit in narrower cockpit. I keep this size at modeling women, but increase width to 5 studs at men. Tchickness will be increased also at both genders, wherewer is needed. GOAL2: Girls and boys are quite a different type of animals: Nowadays there is a global trend of unisexization on many areas of life partly because of preventing discrimination, partly because global companies can make more profit selling mass produced stuff to uniformized masses worldwide. An excellent example is Lego, which made quite an effort of total de-sexualization of Lego figures, probably to keep Arabic and USA/Bible belt markets, where realistic modeling of human body in a toy would cause serious religious concerns. The most realistic is belleville figure, which is also well designed, but designers did take care about that it has the proportions of a small girl BEFORE sexual maturity (11-12 years old). So it looks pretty weird driving an Unimog with a hydraulic crane-arm. So I try to model different sizes and proportions of mens/womens body. Also, I did model that parts which girls and boys supposed to have, even they are covered on the picture, but you can check them out in attached LXF file... GOAL3: If you cannot repose it, rebuild it: My figures are built from ordinary, frequent technic parts can be found in anyone's brickshelf. This affects aesthetic negatively, but it has positive effect on reusability and materials management. We also have to pay the price in limited posability compared to original Technic Figure. This is especially true to female model, but it is still suitable to sit it in a cockpit, in driver's position. BUT, anytime you cannot pose the figure, you can rebuild it a little bit to achieve correct position (eg. females shoulders are 4 studs wide, so elbow will not work correctly, but it can built with straight arm). Also, it is possible versioning mens/womens headform and haircut/beard (we show 4 examples but you can develope your own). In general, bigger sized male figures have more joints and can performe more positions (eg. open up legs to ride motorcycles). This feature is left out from female model to prevent weird guys to shoot weird Lego-movies using my work... GOAL4: Just being handsome: Hand gauge of Technic Figure was the width of Technic connector peg (5mm). Although it fit to Technic, but it was oversized. So I opted to use the same hand gauge as minifig. This way we can use lot of minifig equipment, which are a little bit oversized at scale 1:36 but work well in 1:20. Moreover, being in 1:20 instead of 1:36, we can model some stuff more realistic: eg. see the assault rifle with removable magazine and grenade launcher or the machinegun, with moving belt-feed. In minifig scale, it would be impossible. GOAL5: Personalization: I tried to create Gilian, Angelina, Chuck and Arnie with minor modifications of basic model.

Technic set 852 in 1977 already had collective pitch on main rotor blades with fixed tail rotor blades. So in terms of real helicopter engineering, the only advancement of 9396 are main rotor blades, wihch finally have something to do with aerodynamics, after so many ridiculus attempts (eg. blades at 8068) Compare 9396 with the following MOCs having roughly the same number of components, than decide about its design yourself: Bad Guys Escape Helicopter Steph77's UH-1 The alternative set of 9396 with intermeshing blades is more interesting, but it is not better than A model in terms of helicopter engineering.

BAD GUY’S ESCAPE HELICOPTER Visit my Lego helicopters blog to see the same post together with all pictures and LDD models. 1.Introduction Most LEGO websites are flooded with vehicles of positive superheroes: Batman, Spiderman, X-Man, Y-Man, Z-Man, Whatever-Man… However equipment of bad guys are heavily underrepresented. Therefore, hereby we represent to MOCers community Bad Guys Escape Helicopter (BGEH). Both in Hollywood movies and in the reality bad guys/gangsters/dictators/politicians escape on their personal helicopter when moment of justice/revolution/NATO-bombing/IRS comes. So it is absolutely the first item on their shopping list spending stolen/taxpayers money. BGEH is a twin engined, 4-seat, armed executive transport in 1:20 scale (Lego Belleville/Playmobil figure size) made of 1718 bricks featuring: -2-blade, semi-rigid Hiller-Bell type main rotor with folding blades -2-blade variable pitch tail rotor -Variable pitch elevator surface -Aerodynamic rotor blades with spar-and-ribs structure -6-channel twin controls connected into cockpit: cyclic pitch/roll, yaw, collective pitch, engine throttle, elevator -Twin M-motor electric drive (all these features above are packed into a self-contained Light Helicopter Module) -Powered cargo ramp -Powered rescue winch -Four-barrel, belt-feed rotary gun in nose turret trainable with joystick from cockpit at -21..+26/-30..+30 degrees -Magazine with 100 rounds of ammo -Windscreen with mechanized windscreen wipers -Swing arm-mounted, lockable side doors -Lockable cockpit doors -Folding rear seats -Fully faired airframe -Battery pack loadable into emptied cargo space See model and building instructions in Lego Digital Designer (LDD): BGEH With Guide.lxf 2.Basic idea 2.1.Building BGEH was inspired by work of several excellent MOCers: (This part is technical and for heli builders with at least some experience. If you do not understand something, see: http://www.aviastar.org/theory/index.html about basics of how helicopters work) SgtPepper set up the mark for high-end Lego Technic helicopter modeling with his Aerospatiale Alouette II (about real, see: http://www.aviastar.org/helicopters_eng/snias_alu2.php ) in 2008 with almost photo-realistic modeling of airframe in scale=1:14 (see: http://www.brickshelf.com/cgi-bin/gallery.cgi?f=316589). But it is also very functional with electric drive and 4 channel controls in cockpit. Unfortunately it uses 2-blade main rotor instead of the original 3-blade with Lego swash plate drilled through allowing it sliding on main rotor axis for collective controls. It is interesting because Wojtek already developed functional 3-blade rotor in his Aerospatiale Gazelle (see real http://www.aviastar.org/helicopters_eng/gazelle.php ) in 2006, in scale=1:14, electric drive, 4 channel controls in cockpit (see http://www.brickshelf.com/cgi-bin/gallery.cgi?f=161508 ), but its fenestron (ducted fan) tail rotor left unfinished. One of the finest fenestrons in Lego Tech heli industry can be seen at Samrotule’s Eurocopter Dauphine (see real http://www.aviastar.org/helicopters_eng/snias_dolphin.php ), 2003 in a some what larger scale=1:10, electric drive, 4 channel controls in cockpit, (see: http://www.brickshelf.com/cgi-bin/gallery.cgi?f=32036 ) The closest model to my concept is Steph77’s Bell UH-1 (see real http://www.aviastar.org/helicopters_eng/bell_204.php ) from 2012. He maintained reasonable material requirement using scale=1:18 (Lego Tech figure scale) at the price of less exact airframe. But he managed to model one of the mechanically most complex types of rotors, the Hiller-Bell, with electric drive, 4 channel controls in cockpit (see: http://www.brickshelf.com/cgi-bin/gallery.cgi?f=496125 ) In terms of airframe, I owe much inspiration to Darkenski’s Eurocopter EC145 (see real http://www.aviastar.org/helicopters_eng/eurocopter_ec-145.php ) from 2011, in scale=1:18, electric drive. It has no real controls, but its creator met the challenge to model a modern heli airframe using large amount of composite materials and many CAD-designed curved surfaces (see: http://www.brickshelf.com/cgi-bin/gallery.cgi?f=462815 ) 2.2.Building BGEH was inspired by the following real helicopters: There are 2 generations of German-originated helicopters with so high versatility that they are used „from tank attack to heart attack” (in roles from anti-armor to medical rescue) worldwide. I wanted to create similarly versatile and modular craft. MBB BO-105 from 1967 (see http://www.aviastar.org/helicopters_eng/mbb-105.php ) was twice as expensive as contemporary light helicopters with the double capability. MBB-Kawasaki BK 117/Eurocopter EC145 (see http://www.aviastar.org/helicopters_eng/mbb-117.php /http://www.aviastar.org/helicopters_eng/eurocopter_ec-145.php ) from 1999. I was especially amazed by the Kawasaki-built version, which can have gun turret under the nose. 2.3.Innovations and advancements of BGEH compared to contemporary models: (In the forthcoming technical description, functional parts of BGEH are referenced by numbers which can be found on cutaway drawings) GOAL 1: First Lego heli with functional 6 channel twin controls: The models shown above had all 4 channel twin controls (2 cyclic, 1 collective, 1 yaw control). I added 5th channel of engine throttle control by rotating knob (29) on collective lever (28) and 6th channel controlling tail elevator surface (86) by pitch component of yokes (30) position, just like in real helicopters. GOAL 2: First Lego heli with aerodynamic rotor blades: In my vision, putting a studded bar in the airflow is funny, but only until you play with Duplo. I simply got fed up with that Lego cannot support us with reasonable rotor blades and come up with my solution: A structure of blade spar (50) and ribs (51) covered with duct tape, assuming that decals - which are regular parts in many Lego sets - could play more important role as cover of aerodynamic surfaces. GOAL 3: Fully faired airframe: The usual, gridded-style look of Lego technic models looks nice at cranes, heavy machinery and early helicopters, but it is ridiculous at modeling streamlined, curved forms of modern heli airframes made of composite materials. So I decided that I will maximally utilize Lego Technic fairing panels to eliminate gaps, holes, steps, facets, etc. But the price was that I could not tie myself strictly to model an existing helicopter. Instead I created a mix from MBB BO105, Kawasaki BK117, and Bell Jet Ranger, but strictly adhering to real engineering principles. GOAL 4: Put engines where they really are: Even at models with scale 1:14..1:10, Lego Technic electric motors are usually put „somewhere” in the airframe, and engines are fake. This has negative consequences: e.g. at Steph77’s UH-1, battery went in place of engines, so electric motor went in place of controls before main rotor mast, thus controls went into passenger deck, thus passengers most probably went into the sea. Therefore I tried to incorporate electric motors (61) in place of turboshaft engines. GOAL 5: Windscreens and glazing: Most technic models usually do not have any windscreens or glazing. This is pretty OK. for a bulldozer, but modern helicopters with large curved, one-piece windscreens get a distinctive „burnt-out scrap” look without glazing. Fortunately, introducing Star Wars and other themes in Lego resulted in variety of windscreen and canopy elements we can use with some tricks in Technic. GOAL 6: Modularity: At first, this seems empty marketing slogan, as Lego by default is modular. But it means that all stuff necessary for a twin engined electric helicopter with 6-channel twin controls in cockpit are incorporated into a self-contained Light Helicopter Module (LHM), with which you can build wide variety of helicopters. GOAL 7: Reasonable materials requirement: I reduced the scale from 1:18 (Lego Tech figure scale) to 1:20 (Lego Belleville/Playmobil figure scale). As material requirement changes in average third power of the scale of the model it has definite positive effect on reducing costs. Even if whole BGEH consist of 1718 bricks, the LHM - which contains all vital parts of a helicopter – is made from only 628 bricks, avoiding any rare or exotic parts. 1090 bricks are spent on airframe, auxiliaries and armament… I paid the price of re-scaling in that I had to develop compact, simplified, but still functional structure at main- and tail rotors, which was challenging. 3.Light Helicopter Module (LHM) See model in LDD: Light Helicopter Module.lxf The purpose of LHM is to pack ALL FUNCTIONALITY (except battery) of a twin-engined, electric driven Lego technic helicopter with 6-channel twin controls in cockpit into a self-contained unit made of 628 bricks. With its help, you can create helicopter from almost any light land/sea vehicles, replacing their roof with LHM, if they have at least 10 studs long × 9 studs wide × 9 studs tall internal space to accommodate cockpit and controls. To support this, creating LHM I intentionally avoided using any exotic/rare bricks: material requirement of core components can be found at almost anyone’s brickshelf. Let’s see its functions more detailed: See dynamic systems in LDD: BGEH Dynamic Systems.lxf 3.1.Main rotor To understand why building a compact Hiller-Bell type main rotor was a big challenge, we have to see through types of helicopter rotors very shortly: 3.1.1.Bell-type rotor We show an example of the most simple helicopter rotor at SgtPepper’s Alouette II: Rotating part of swash plate (black) is directly linked to variable pitch rotor blades with pitch rods and ball joints (marked with red and yellow). Usually, between these rods there is a small scissor-jack keeping rotating part of swash plate aligned with main rotor mast, while still enabling swash plate lower/raise vertically on main rotor mast for collective control. Static part of swash plate (grey) is linked to: -its rotating part with a large diameter bearing, -to main rotor mast with a central ball joint, which can also slide on main rotor mast -to collective and cyclic control rods (dark grey and black) with ball joints SgtPepper used here the Lego Technic swash plate part, which has several problems: -It is bulky (6×6 studs) resulting large rotor hub with 8 studs diameter and 13 studs tall -It is not designed to serve as swash plate, but to tilt rotor as one monolith unit around main rotor mast, which is practically unworkable and misleading. A real swash plate has ball joints of both static and rotating part in one plane -Moreover, it cannot slide easily on main rotor axis so poor MOCers have to drill it enabling collective control, which is not really Lego-compatible move. The same functionality of Bell-rotor can be achieved with much more simple and compact structure, if we omit Lego swash plate. The example is my earlier model, the oTo Helichopper (http://www.mocpages.com/moc.php/327183): rubber band (8) acting as a torsion spring gently forcing blades into zero degree pitch relative to each other. Thus red pitch rods jacking on yellow hinges are pressed down to swash plate. Swash plate here is a flat, non-rotating plate can be tilted and lifted around main rotor axis by sliding cardan-hinge. A 6-hole disk fixed to main rotor axis drives pitch rods, whose lower tip slides on swash plate, thus we do not need any bearing. When swash plate is lifted or tilted, pitch rods will increase blade pitch from zero against the force of torsion spring. Rotor hub has 3 studs diameter and 5 studs height (all the extra stuff outside this are to make blades foldable). Quite a difference. The general advantage of Bell-rotors is simplicity, the disadvantage is lack of any automatic stabilization, so it is very demanding on piloting skill or requires difficult avionics 3.1.2.Hiller-type rotor A somewhat more complex rotor using Flybar stabilizator (as an example, see my earlier Light Assault Helicopter model: http://www.mocpages.com/moc.php/300772 ). Flybar (grey rod) is a pendulum-like device fixed with cardan-hinges to main rotor axis transversal to rotor blades. It tries to keep its original plane of rotation because of its gyroscopic torque in case the helicopter is tilted by disturbances in airflow. Changing the cyclic pitch of rotor blades through control rods, it counterbalances tilting. In Hiller system, the pilot can shift only the plane of rotation of flybar with collective and cyclic controls through the swash plate, and only the flybar controls main rotor blade pitch. It has the advantage of increased stability over the Bell-rotor, its disadvantage is less responsive control. 3.1.3.Mixed Hiller-Bell rotor Thus, there is a mixed system called Hiller-Bell, which results in stable AND responsive, but mechanically more complex rotor. We show Steph77’s UH-1 as an example: here BOTH flybar and rotor blades are linked to swash plate with rods and ball joints to mix manual input from pilot and gyroscopic torque of flybar in blade pitch control. However, there is a nasty difficulty: swash plate makes relatively big vertical movements in collective pitch control compared to fine correction movements of flybar. Thus, while blades are connected with swash plate with simple straight rods (black) flybar can be connected with swash plate only with a complicated jacking mechanism (light and dark grey) compensating vertical swash plate movement and aligning rotating part of swash plate to rotor blades. This is the weak point in Lego Technic where minimal cross-section of any parts is 1 stud: both for main rotor mast and small jacks, which are at least 5 times thinner in reality. So the rotor hub will be quite bulky: 9 studs diameter and 14 studs height. At BGEH I created simplified Hiller-Bell main rotor with lifting flybar: swash plate (39) is a flat plate with a hole in the middle letting through main rotor mast (45). It can be tilted in any direction by cyclic swing arms (38) and pushrods (24), and lowered/lifted by collective lever (18). Flybar (40) is lowered/lifted together with swash plate, because 2 rollers built in flybar hub (43) roll on that. Flybar can be tilted in any direction around main rotor mast (45), which has an ½ Bush closely rounded by flybar hub components. This solves centering flybar on main rotor mast. Leading slides (41) and leading swing arms (42) keep flybar strictly transversal to rotor blades, but allow its all necessary tilting and lifting movements. Plane of rotation of flybar hub (43) is influenced: -Partly by manual cyclic and collective input from swash plate (39) through rollers. -Partly by gyroscopic torque of flybar masses (40). Blade pitch rods (44) are linked to flybar hub (43) offset from its centerline, so they are mixing manual - flybar torque input in proportion 60% - 40%. This solution eliminates the need of complicated jacking mechanism between flybar and swash plate consisting of small parts. Therefore, main rotor hub can be more compact: 8 studs diameter and 7.25 studs tall. Blade pitch rods (44) change the pitch of blade locking sleeves (46), which nest the inner end of blade spars (50). Rubber tie (48) acts as a torsion spring gently forcing blades into zero degree relative pitch. This way, rollers of flybar hub (43) are pressed down against swash plate surface (39) through blade pitch rods (44). When swash plate is lifted or tilted, it will lift/tilt flybar against the force of torsion spring, and flybar will increase blade pitch from zero through pitch rods. Blades can be folded into storage position around blade folding hinges (47) disengaging end of blade spars (50) from blade locking sleeves (46). 3.1.4.Aerodynamic rotor blades Rotor blades are the most controversial part of my design. I simply got fed up with that Lego cannot provide us reasonably aerodynamic rotor blades. They introduced specialized rotor blade component at set 8046 in 2010 but they put studs in the middle of it making it pretty ridiculous. Building bigger blades from studded plates and flat tiles gave trouble to every MOCer. E.g. SgtPepper wrote that blades of Aerospatiale Alouette II were too heavy, even using 2 instead of 3… Therefore I created structure of blade spar (50) made of the longest Technic rod (32 studs) part and blade ribs (51) made of „Bionic eye” part covered with duct tape: -These blades are aerodynamic, strong and lightweight even at large size. They are still very far from a patented NACA (National Advisory Committee for Aeronautics)-aerofoil section, but they made their effect. When I prepared the open-air photos of my earlier model oTo Helichopper http://www.mocpages.com/moc.php/327183, there was medium wind, and blades did what they are proposed to do with annoying flipping-flopping. -Most duct tapes are 48mm (2in) wide, so they can be applied to 3 studs (24mm, 1in) wide blade ribs in 2 strips: Strip A is stickled first by its half-line to trailing (rear) edge of the blade, and bent forward gently to ribs. Strip B is stickled second by its half-line to leading (front) edge of the blade, and bent backward gently to Strip A and ribs. This way sticking upper and lower half of cover can be avoided by the elasticity of the tape. However, duct tape is not quite a regular Lego component… BUT: -Decals are already well-known technology for Lego being part of many sets, so they could be used as structural stressed skin components of machines instead of just being decoration. -They are cheap and comply children safety rules as long as they are not enough big that kids can strangle each other with that -Larger areas of cover can be stickled together from smaller standard parts -Duct tape material technology made serious improvement in recent years using high tensile strength plastic foils, water-resistant glues, sticky surfaces renewable with simply washing it with detergent, stretchable foils keeping their shape, etc. -Combining decal covering with stiff/elastic rod structures would provide excellent modeling tool for real world’s welded steel/Dural tube structures covered with glass/carbon fiber reinforced resin: e.g. most racing cars, rigid wing aircrafts, hovercrafts, light ships, etc. -Mildly curved surfaces e.g. windscreens of cars/planes could be modeled with ease (And Dear Lego Guys, when you will design the next “bionic eye” part for future Godzilla/ Tyrannosaurus/ Alien/ Lady Gaga sets, can you accidentally use the shape of NACA 712A315 aerofoil, thanks.) 3.2.Tail rotor It is a simple two-blade construction, where blades (67) have the same structure as main rotor blades. Blade pitch rods (66) are connected with an assembly which has 4 ears (65) and can slide on tail rotor shaft (120) left and right changing blade pitch. This slide is controlled by pitch control lever (63) which forces a roller (64) in the gap between the ears (65). Tail rotor is protected from hitting the ground by a Bell Jet Ranger-style vertical stabilizer surface. 3.3.Transmission and engines Main rotor is geared to tail rotor at 36:100 ratio in two-step reduction gearing assembled from Z12 and Z20 conical gears (111, 112). Two M-sized electric motors (61) are geared to main rotor 1:1. This is because M motors already have built-in reduction gearing, and two of them have enough total torque to drive main rotor 1:1. (But, in case of using motor without internal reduction gearing, gearing ratio can be changed to 36:100 easily just switching the Z20 conical and Z12 half-conical gear with each other at the motor.) Motors are connected with main rotor reduction gearing through short (2 studs) cross-axles, which have two Z12 half conical gears, this leaves 1 stud gaps between main rotor assembly and engines. It is usual gearing layout at real battle helicopters (e.g. AH-64 Apache), because the distance between engine and main rotor reduction gearing prevents single explosive shell taking out both of them in the same time. At LHM, I use this 1 stud gap to lead control rods of yaw (23), elevator (87), 2 engine throttles (26, 91) lead through from forward to back side of main rotor in a compact way. Without the gap, it would be troubleful. 3.4.Controls (Note: handles of functionally working controls are built in yellow color in the model.) With the trick described above, I could solve all controls with control rods avoiding usage of control wires. SgtPepper at Alouette II and Steph77 at UH-1 used wires for yaw control, as the real aircrafts use them. I also used them at my previous model oTo Helichopper http://www.mocpages.com/moc.php/327183 but their usage proved very troubleful in Lego Technic. Parts made of ABS easily twist and bend when control wires are correctly tensioned making them loose and useless. 3.4.1.Channel 1-2: Cyclic pitch/roll Tilting twin yokes (30) are synchronized by roll synchronizer rod (30) and pitch synchronizer shaft (124). It will change position of lower cyclic control swing arms (131), which transmit control through ball joints (108) to lower cyclic control pushrods (130). These will rotate cyclic swing arms (21) through cyclic control hinges (132). Cyclic swing arms will push/pull upper cyclic control rods (24), which will tilt swash plate (39) through its swing arms (38). 3.4.2.Channel 3: Yaw control Yaw control pedals (31) move yaw control sliding block (121), making lower yaw control rod (123) sliding forward/backward through slide (122). This moves small yaw control swing arm (126), which is fixed on a cross-axle in the cushion part of the left pilots seat together with medium yaw control swing arm (127). It moves vertical yaw control pushrod (129) through ball joint (128). It moves upper yaw control swing arm (22) through yaw control hinge (133). The swing arm moves upper yaw control rod (23) through a ball joint. Upper rod (23) will transmit yaw control to the tail to tail rotor pitch lever (63). 3.4.3.Channel 4: Collective pitch Raising collective control lever (28) will rotate it around its pivot (125), pulling downward a 2-part collective pushrod (18, 109). It will raise collective lever (18) rotating it around its pivot (20). Collective lever (18) will lift swash plate (39), and flybar (40), which will increase blade pitch collectively. 3.4.4.Channel 5: Engine throttles Turning throttle control knob (29) on collective control lever (28) will rotate lower throttle swing arm (107), which will move upper throttle swing arm (89) through a vertical pushrod and its ball joints. This swing arm will turn engine throttle pivot axis (135), where there are two smaller swing arms (25, 107) fixed on its both ends. Small swing arms will move upper throttle control pushrods (26, 91) both for left and right engine. Pushrods move engine air intake nozzles (60) for throttle control. 3.4.5.Channel 6: Elevator pitch Vertical elevator pushrod (101) is linked to lower swing arm of right yoke (131) to receive pitch component of yoke’s movement. Pushrod (101) will move upper elevator swing arm (88), which moves upper elevator pushrod (87) through a ball joint. Pushrod (87) transmits elevator control to tail, changing pitch of elevator surface (86). 4.Airframe I tried to create streamlined, faired and lightweight airframe, maximally utilizing Technic fairing panels and flexible rods, and Star Wars windscreen elements 4.1.Windscreens and wipers Windscreens are made from part „Screen bowed 4×8×2” connecting them with part „Fric/stump with crosshole” to Technic airframe structure. Windscreen wipers were inspired by Darkenski’s EC-145. There wipers are static and do not follow lines of windscreen very well. Therefore, I placed a mechanics for them from two Z16 gears at the front edge of head instrument panel, which ensures correct movement of elastic wiper arms. 4.2.Cockpit doors They are the weakest part of my design as I could not find any glazing matching their shape. Part „Gate 4×8” has correct size and half-rounded shape, but it is not available in transparent color. Part „Door for wall element” available in transparent, but it is too long. Of course I could cover cockpit doors with transparent duct tape any time, just like rotor blades, but it would be too easy solution without challenge. To compensate my reluctance, I equipped cockpit doors with lock, inner- and outer opening knobs (82, 117), and rear view, truck-style side mirrors (118) (they are used to check rotors and rescue winch crane during flight). (Note: at top corner of doors, there should be part „angle element 0 degrees”, just LDD could not match it with flexible frame, even using flex and match tools. Pity. In the reality, of course it is not an issue.) 4.3.Side cargo doors See model with doors open and blades folded in LDD: BGEH Doors Open.lxf In the reality, most helicopters have side cargo doors backward sliding on rails. However, this is a trap in Technic, as minimal thickness of any door built from more parts is 1 stud. So it will create a very nasty and disproportional 1 stud step on the side of a 9-11 studs wide cabin as we can see it at Darkenski’s EC-145: Therefore, I placed 8×11 stud sized side cargo doors on 6×2 stud, L-shaped swing arms (57), which can rotate 180 degrees: when they are in forward position, doors are locked, PERFECTLY IN LINE with cabin wall, and cushioned top of swing arms serve as arm stands for back seats. When swing arms are backward, they extract side doors from cabin wall 2 studs and move them backward 10 studs. Each cargo doors have two „train windows” and between them there are latch-type door locks with inner and outer opening ears (99) 4.4.Cargo ramp Light and medium sized helicopters usually do not have lifting cargo ramp, just 2 streamlined „clamshell doors” made of glass fiber reinforced resin. However, modeling clamshell doors in Technic is troubleful as we can see in Darkenski’s EC-145: there are quite a gaps around door where poor rescued guy and its casevac can fall off in sharp turns… Therefore, I decided to build a two-piece, liftable, powered cargo ramp, which is mechanically more challenging than clamshell doors, but it can be faired easier with existing Technic panels. The ramp consists of two jacking pieces, the larger lower (71) and the smaller upper (72) part to better follow streamlining of the end of the cabin. Ideally, ramp should be lifted by a separate electric motor, but even the smallest type of Technic motor is too bulky and heavy for this – we have not enough space there. Therefore lower shaft of tail rotor reduction gearing (112) is extended backward and continued in an universal joint (113). This transmits drive to a ½ conical gear (114), which can slide on a short axle, forced by lift drive clutch lever (116) and pushrod (73). When the pushrod is pressed backward (accessible from left rear seat), gear (114) is connected with lifting gear and axis (115), which has ramp lifting hinges (74) at its right and left ends. Rotating 2 hinges pull 4 swing arms of ramp parts (75) through 4 pushrods (76) and ramp is lifted. Ramp lock rod (95) has a hook catching the left hinge (74), locking ramp in closed position. Pulling ramp lock rod to the left (accessible from right rear seat), the hook disengages, and ramp parts go down in line with cargo space floor by their own weight. The big challenge in building this was that lifting mechanism could be 1 stud wide on both sides to preserve 7 studs × 6 studs maximal cargo gauge using the ramp. The maximal cargo size can be loaded with ramp lowered is 7 studs wide × 6 studs tall × 24 studs long. Such an oversized cargo can be fixed to hooks (140) on ramp floor. When ramp is lifted, main cargo area can still accommodate cargo 7 studs wide × 7 studs tall × 11 studs long, as side doors have bigger maximal gauge than the ramp. See model with empty deck in LDD: BGEH Empty Deck.lxf 4.5.Rescue winch It is nearly the same story as cargo ramp: powering it would require a separate electric motor, but there is not enough space for that. So winch gets its lift/lower drive connecting left/ or right ½ conical gears (92) placed on spool axis with a swing arm to forward stage of tail rotor reduction gearing (111). This device eats only 1 studs space on main cargo space roof. Rope is lead from winch to crane arm (93) between throttle control rods (91) of right engine, which has rollers to drive rope. Crane arm (93) can be rotated 90 degrees above cabin roof to reduce drag when it is not used. 4.6.Toilette module Most bad guys/gangsters/dictators/politicians consider themselves immortal gods, or at least semi-gods who can do anything without any consequences. So they won’t eat, wear, drink what ordinary people do. And they will not use public restrooms… Therefore a decent personal helicopter should provide all these amenities on luxury level. Toilette module is a lightweight structure can be easily fixed and removed from main cargo space floor including toilette (54), hand wash basin (53), cabinet (52), entrance door (98). On the outer wall of the module facing towards back seats (56) has LCD TV (55) (made from part „train window”, whose back is covered with parts „container door”), intercom (100) and A/C unit (96). When toilette module is installed on cargo space floor, it locks left cargo door in closed position. So one cannot suddenly open it revealing the „big man” in desperate need… Toilette outer window has darkened glazing, but it is still the toilette with the greatest view on the face of the Earth. 4.7.Folding back seats The primary motivation behind torturing and massacring ten thousands of innocent people - regularly made by bad guys - is to accumulate enough money and power to hunt down most expensive girls and top models. (e.g. Kaddafi’s amazon bodyguards, Silvio Berlusconi’s unga-bunga parties, Saddam’s lovers, etc.). Or, hunt down not-so expensive girls, after lot of alcohol (e.g. Dominique Strauss-Kahn). A personal aircraft – as a symbol of status and power – can be an excellent device for womanizing activity if it provides discrete environment (e.g. Catherin Hepburn and Howard Hughes in PYB Catalina hydroplane in the movie Aviator). Therefore, back seats can be folded backward to create double bed releasing locking handles (58) and flipping down locking ears (59). Still with this help, life can be a boring routine for bad guy’s girlfriend aboard BGEH: morning – poison gas bombing of a rebel mountain village, noon – skiing in Swiss Alps, evening – cocktail party with celebs in Hamburg. To create some excitement, lid of toilette (144) is foldable and toilette paper roll (145) is rollable, providing excellent battlefield for women’s hysteria. 4.8.Placement of battery pack See model with battery loaded in LDD: BGEH Battery Loaded.lxf Lego Technic battery pack is too bulky and heavy to build in fixed somewhere in the airframe in scale 1:20. It would totally destroy styling. But BGEH can carry it as cargo when cargo deck is cleared. I will wait with integration of battery pack into the structure until Lego develops more compact, light, higher capacity and rechargeable Li-Po battery pack. This way, they could reach at least the technology level of cheap mass-produced Chinese mobile phones… 4.9.Fuel tanks In the reality, kerosene fuel of turboshaft engines is stored in the 2 large hollow spaces (2×7×11 studs) of cargo deck floor and lower cargo ramp floor can be filled trough cap (139). 4.10.Landing skid In most Lego Tech heli models landing skids are parallel with plane of main rotor disk area. However in the reality, cabin and rotor is put on skids somewhat backward tilted to make autorotation crash landing easier. I used 3.75 degrees backward tilting on skids (35) at BGEH. Moreover, it is important, because rear end of cargo ramp can touch ground, when lowered in level with cargo deck floor. This makes loading and unloading easier. 5.Armament Sooner or later, moment of justice/the good guy/revolution/the next bad guy comes for every bad guy, when survival depends on BGEH. Don’t repeat the mistake of Fantomas, who built a jet-powered, flying Citroen DS-19, but forget to put there any armament. Pity. 5.1.Four-barrel 12.7mm(0.5in) rotary gun in nose turret See gun turret in LDD: Gatling Gun Turret.lxf This gun is modeled after the Russian diminutive of the famous American M61 Vulcan 6-barrel rotary gun, which was used in Mil MI-24 battlefield helicopters. It is little bit oversized for a light helicopter. I paid the price of it in limited arcs of fire (-21..+26 degrees vertically and -30..+30 degrees horizontally), but creating it was challenging. Belt of 12.7mm (0.5in) ammo is modeled with motorcycle chain parts (Note: In LDD, this type of chain cannot be twisted, but it tolerates that pretty well in reality). To save space, I omitted parts of gun behind its rotor (151): bolts, springs, catches, etc. Gun turret can be controlled with joystick from cockpit through laying pushrod (152), which rotates trunnion directly. Training is made by training pushrod (153) rotating training lever (7), which drives training transmission gear (105) through rotating axis of trunnion. Gear (104) rotates training gear of gun (105). Behind fixing hardpoints of turret (154) there is a magazine for belt of 100 rounds (106). Belt is extracted from magazine by extractor gear (155) and received at gun by receiver gear (5), which is driven by gun rotor (151). This type of gun has firing rate of 4000 shots/min in the reality, so it can empty the whole magazine in a 1.5 second-burst, but I had no more space for magazine, and motorcycle chain is not very compact. 5.2.Six TOW missiles TOW stands for Tube-launched, Optical-targeted, Wire guided anti-armor missile developed by Hughes Aircraft in 1971 and continuously improved since that. Its advantages are relative cheapness and accessibility. As it is re-engineered and manufactured by Iran also, it is an everyday commodity on illegal weapons market for bad guys. As the missile is controlled during its flight by electric signals traveling on a double piano wire spooling down from a coil, it is relatively safe against Electronic Counter Measures (ECM). Disadvantages are limited range by wire (max. 3750m), limited speed to prevent tearing the wire (187m/sec in average) , limited armor piercing (630 mm) by 3.1 kg HE warhead, and the biggest one: launching platform has to keep target in line of sight during whole flight time of missile (max. 20secs) being an easy target itself for AA guns. Its semi-automatic optical guidance requires a gyro-stabilized periscope sight (15) with an ocular (85). At helicopters it is usually placed at cockpit roof, this way at least the cabin of the helicopter can be behind some cover during targeting. Modeling the missile launch tubes (80) in scale 1:20 was not an issue, as their real diameter (0.15m, 6”) matches pretty well with 1 stud diameter-tube parts. Missile weapons can be attached to retractable side weapons consoles (79) on both sides. When they are employed, they lock side cargo doors in closed position, but cargo deck is still accessible through cargo ramp. 5.3.Two Hellfire missiles Hellfire is a more modern and potent fire-and-forget weapon with semi-active laser homing produced by Lockheed Martin. Thus, it is much more hard to access for bad guys. I included it because of modeling challenge: the missile is launched from short rails, and I wanted to solve it as it is. The key was „Tacho 8”, an 8-winged stabilizator-like part (161), which has small T-hooks at the end of wings. These hooks can go between rails of „1×2 plate with rail” parts (162) in the reality, even if LDD cannot handle this. The difficulty was that rails had to be spaced in a distance, which did not match any standard Lego part size. Therefore, I hanged assembled rails with parts „1×1 plate with holder” on 4-stud cross-rods named „Lightsword” (165). This way, gap between rails can be freely adjusted to safely hook missiles (97) by T-hooks. 6.Dimensions of BGEH: Main rotor diameter: 69 studs/ 552mm/ 21.73” in real size: 11.04m / 36’ 2.36” Main rotor disc area: 3739.28 sqstuds/ 0.239sqm / 370.93sqinch in real size: 95.72sqm/ 1029sqfeet Tail rotor diameter: 16 studs/ 128mm/ 5.04” in real size: 2.56m / 8’ 4.72” Tail rotor disc area: 201.06 sqstuds/ 0.013sqm / 19.94sqinch in real size: 5.147sqm/ 55.33sqfeet Distance between main- and tail rotors: 39 studs/ 312mm/ 12.28” in real size: 6.24m / 20’ 5.51” Height: 25.25 studs/ 202mm/ 7.95” in real size: 4.04m / 13’ 2.95” Cabin size: 11studs/ 88mm/ 3.46”wide × 12studs/ 96mm/ 3.78” tall × 44studs/ 352mm/ 13.86” long in real size: 1.76m/ 5’ 9.25” wide × 1.92m/ 6’ 3.54” tall × 7.04m/ 23’ 0.98” long Largest loadable cargo size (with lowered cargo ramp): 7studs/ 56mm/ 2.20”wide × 6studs/ 48mm/ 1.89” tall × 24studs/ 192mm/ 7.56” long in real size: 1.12m/ 3’ 8.07” wide × 0.96m/ 3’ 1.77” tall × 3.84m/ 12’ 7.09” long Minimal storage space of BGEH with folded blades, without armament: 15 studs/ 120mm/ 4.72”wide × 26.25 studs/ 210mm/ 8.27” tall × 73 studs/ 584mm/ 22.99” long in real size: 2.40m/ 7’ 10.43” wide × 4.20m/ 13’ 9.25” tall × 11.68m/ 38’ 3.54” long 7.Unsolved problems and shortcomings - There is only one collective lever/throttle control for 2 pilots, so one of them should be left-handed: This was not because technical limitations, but I wanted to keep 9 studs internal gauge of cockpit. Wider cockpit can be done with twin collective lever. - Cyclic and collective controls are interlinked: changing collective pitch will influence cyclic pitch also and should be compensated on yokes. This is because there was not enough space for 4 dislinker levers in the already crowded controls housing. It is the price of the 1:20 scale. - Tail rotor is too close to main rotor and too close to ground, and disturbs usage of cargo ramp: Bell Jet Ranger-style straight tail boom should be replaced with angled tail boom and universal joint on tail rotor transmission shaft, even it will increase minimal storage size. - There are no flapping hinges and yaw dampers in main rotor. BGEH is already too big and too heavy using semi-rigid rotor. - Correct gearing ratio between main- and tail rotor should be 10:100 instead of 36:100 - There are no centrifugal clutches between engines and main rotor gearing, which would prevent stalling engines destroying inertia of the autorotating main rotor. - Gearing ratio of cargo ramp lift and rescue winch is insufficient: both of them should use clutchable worm drive, but there was not enough space for that. - Cargo doors can flip-flop in rotor downwash when their swing arms left half-open: there was not enough space left for secondary swing arms securing it. - Cargo ramp tends to jam at lowering, when there is not enough weight on that - Cockpit doors have no glazing. 8.Building guides See building guide: BGEH With Guide.lxf Complexity of BGEH put guide-generating algorithm of LDD on hard testing. This algorithm most probably starts from center of gravity of the model, and seemingly tries to group similar parts in each others proximity into sub-modules. Also it seemingly checks collisions of sub-modules during assembly at some level, but no fully. However, the fully faired design confused up it totally: - First, during 370 steps, it builds all the internals of the helicopter, then puts it aside. - Second, it builds up the „empty skin” of fairing elements in more than 200 steps. - In the final, 618th step, it tries to pull the whole „skin” on internals in one step, just like a robe, which is funny, but totally impractical. You may use the building guides of sub-models (e.g. LHM) instead of this. 9.Recommendation The idea of this twin-engined, twin-controlled helicopter is born on the same day as my twin sons – Daniel and Szilard – so I recommend it to them. 10.To be continued… My next Lego Technic heli has 6-blade main rotor with 148 studs (1.18m, 3’10”) diameter. So stay tuned…

I saw this picture once in google, but did not store in my memory as it was very far from engineering reality (eg. main rotor has no transmission like at autogiros, but there is no forward propulsion) I tried to make something similar but strictly tying myself to real engineering principles and functionality. You can the see same post in more readable format at MOCPages (search for "Helichopper" ...), because I could not upload all neccessary pictures for explanation at Brickshelf. Interested readers are invited to see MOCPages. There you can see together number coded pictures with their explanation.

Building instructions in LDD 1.Introduction I hesitated long before buying 8051 Racing Bike because I thought it was overpriced, but then I got it at sale. The strong selling point was styling: it is the fanciest Technic bike ever launched by Lego. Unfortunately, high style is not accompanied by high functionality. Lego guys did their best creating reasonably good wheel, shock absorber/spring, chain components. But there are annoying mistakes in the current design: -Both wheels have brake disks but there is no any brake assembly and any connection with fake brake levers placed on horns. -Front wheel has no fender, so it sprays mud directly into coolant radiator behind that, reducing its effectiveness. -Exhaust manifolds (2 bevel gears) are placed at 2 cylinders of the 3-cylinder in-line engine, but exhaust tubes are not connected to them: instead of it, they start out somewhere from the gear shift. -There are plenty of gears at the place of gear shift, but they form only a simple fixed transmission. -Chain does not match very well with distance of transmission gearing: taking out one unit from the chain, it is already too short, adding one unit results in too loose chain tends to buckle and jam during operation. Of course it is more easy to criticise someone else’s design than building my own. So, its time to put there more engineering thought to achieve some extra functions: I built a helicopter-motorbike hybrid called oTo Helichopper solely from the components of 8051 set (including spare parts for the alternative model) featuring: Right front in road mode Left front in road mode Right level in flight mode -2-blade, semi-rigid, Bell-type main rotor with aerodynamic rotor blades foldable alongside the vehicle -Main rotor mast foldable backward 60 degrees -Swashplate for main rotor with cyclic (pitch/roll) and collective control levers -Fenestron-type, 2-blade, variable pitch, ducted fan tail rotor integrated into rear wheel hub -Echeloning yaw control pedals connected with tail rotor pitch arm through cables -Retractable rear landing gear/trolley with lifting/locking mechanism -Horizontally opposed 2-cylinder engine -2-speed gear shift connected through bowden cable with gear shift lever placed on right horn -Front disk brake connected through bowden cable with brake lever placed on left horn -Adjustable headlights -Front fork lock mechanism -Front wheel-mounted, 7.62mm, belt-feed machinegun trainable from +60 to -30 degrees vertically, and from +60 to -60 degrees horizontally -Ammunition drum integrated into headlights   2.Basic idea: The idea of the roadable aircraft (see Roadabletimes for their history ) was born from the desire of „flying over the traffic jam”. For my generation, the Star Wars-trilogy gave another push with empire troopers zooming among woods on jet bikes. Departing from an „airfield” with average size of 5×2.4m/17’×8’ rounded with other vehicles, road signs, traffic lights, lantern masts, air cables and other nice&sweet stuff requires excellent VTOL (Vertical Take Off Landing) capability. Done by an aircraft foldable into the dimensions of a full size car… The engineering challenge is incredible: -Even ultralight aircrafts usually have 8-10m/26’-33’ of wing lenght/rotor diameter to produce sufficient lift, so if rigid/rotary wings are used, they should be foldable, which is risky and requires high-tech materials. -If smaller ducted fans are used to save space, it has two disadvantages: 1. The higher the speed of air downstream, the less fuel-efficient it is. 2. The craft is not able to make controlled dead-engine crash landing. So the nasty FAA (Federal Aviation Administration) won’t certify it – and they are right: Designers of such crafts usually recommend ballistic parachute for crashlanding. But if you deploy it from a destabilized, rolling craft, flying low, it is merely an invitation to your funeral. -Sizeable wheels, suspension, chassis providing reasonable road safety are just too heavy to fly or they should be made of expensive composite materials -Ideal placement of COG (Center Of Gravity) and wheel layout is very different between road vehicles and aircrafts, which can be bridged with complicated folding wings/tails/landing gears Answers to the challenge include some expensive media hoaxes (Moller), unmanned military drones (Urban aero), but recently 2 FAA-certified crafts (Terrafugia and Pal-v ). My model is a tribute to the Dutch guys creating PAL-V, a roadable 2-seat autogyro, solving tremendous engineering challenges with 10 years of hard work: -Electronic controlled rear suspesion of tricycle wheels to tilt the craft in road turns to maintain speed -Retractable tail boom and rotor blades folding into 2 pieces – a risky solution requiring aerospace materials, careful maintenance and expensive spare parts. -As it is an autogyro, not a helicopter, it still needs 50m/42yards space to take off instead of the 5m/17’ we have in the traffic jam.   3.Basic configuration and purpose of the oTo Helichopper: Left top view Therefore I opted for a hybrid helicopter-motorbike with main rotor mast tiltable backward, thus rotor blades foldable alongside the vehicle. This layout allows the maximum rotor diameter with the smallest folded vehicle size using one piece-blades. So blades can use relatively cheap conventional materials, eg. Dural tube spar with glass fiber reinforced resin ribs and cover. Tail rotor is more nasty story: omitting or minimizing it requires more bulky coaxial main rotor (eg. Kamov Ka-56 coaxial personal helicopter for marine special ops) or rocket/ramjet powered blades with incredible noise and fuel consumption (usually from very expensive and dangerous hydrogen peroxide). Both solutions cannot fully eliminate tail boom, as during autorotation crashlanding flight it is required to carry vertical stabilizer surface. Therefore I selected integrating fenestron-type tail rotor in the hub of a large sized (0.95m/38” tyre and 0.7m/28” rim) rear wheel. Its disadvantage is more short arm of force than conventional tail boom requiring more power to counteract main rotor torque. However a variable pitch ducted fan can be more effective than a conventional tail rotor, moreover it means definitely less noise and vulnerability. Wheel size requested was the primary reason to change scale of the model from 1:6 of the original 8051 Racing bike (roughly Barbie-figure scale) to 1:10 (1 stud = 0.08m/3.2”). This is not very frequent scale in Lego (Minifig scale is 1:36..1:38, Technic/Belleville figure scale is 1:18..1:20) but there were some sets (eg. 9392 Quad) close to this scale. An additional positive effect was that material was enough for a more complex model (material requirement increases/decreases roughly on 3rd power of linear size). One can see that oTo Helichopper has armament. Why? First, I do not think that roadable aircrafts are economically viable in civilian/commercial use: you can get far better separate car and aircraft at lower price. Second, they require excellent piloting skills because of their complexity. In my vision, the only area they can succeed is law enforcement patroling and special operations forces, where time of transition between air and road is critical. So, costs of mechanical complexity and excellent piloting skill can be justified. For example, think about the Utoya Isle massacre happened in 2011 Norway: police officers notified by victims on mobile phone were ashore within 5 minutes, then they spent 50 minutes to find a boat to make the last 300m on water. Communication towards airborne units was inferior. It costed lives of dozens of innocent people. The purpose of oTo Helichopper is – whenever heavily armed criminals are encountered - to convert a police cruiser patrol into an „air force of one” in 1 minute, and hunt them down from the air at high speed. Helichopper has road size of 3.5m/12’ lenght × 0.85m/3’ width × 1.75m/6’ height, which is somewhat bigger than a police cruiser bike, but smaller than a compact car. Main rotor diameter in flight configuration is 4.8m/16’, total height 2.1m/7’, safe clearance height under main rotor is 1.9m/6’, distance betwen main- and tail rotor hub is 0.95m/3’. Tail rotor fan duct diameter is 0.7m/28”. Main rotor disc area is 18.09sqm/200sqfeet, maximal takeoff weight based on 12kg/sqm (2.4lbs/sqfeet) maximal rotor disc area load for safe autorotation crashlanding is 217kg/482lbs. Assuming 80kg/178lbs for pilot, 8kg/18lbs for 7.62mm machinegun and 3kg/6.6lbs for ammunition, 22kg/49lbs for 30 liters/6.6imp gal 100 octane petrol fuel, 3kg/6.6lbs for lubricant, 3kg/6.6lbs for liquid coolant, its maximal unloaded dry weight should be 98kg/218lbs, which is very demanding and assumes usage of lightweight composite materials everywhere – a very different technology from conventional chopper building. Lets see it more detailed: 4.Main rotor Main rotor hub Creating the main rotor, the biggest challenge was that in 8051 set there was no any specialized parts necessary for helicopter rotor: 4 ball joints, large diameter bearing and cardan-hinge for swashplate (About working of helicopter rotors and controls, see April 2011 archive of http://technic.lego.com/en-us/Designers/Blog/Default.aspx). Moreover, I had to create a rotor with blades foldable along main rotor mast, which complicated mechanics further. Therefore I selected the simplest possible type of rotor: 2-blade, semi rigid, Bell-type. Both blades can be pitched around an axis peripendicular to main rotor axis nested in (1) hinge. However (9) blade is fixed on cross-axis, while (10) blade can rotate around that, but not entirely freely: (8) rubber tie – which was used merely to bridge unmatching geometry in 8051 – acts as a torsion spring forcing blades at 0 degree pitch default position relative to each other. A counterweight on (9) rotorblade spar balances the weight of torsion spring to keep the rotor balanced. Blades can be folded along main rotor mast by (6, 3) hinges turning around (11, 12) axises 90 degrees. Blades are locked in open position by (4, 5) sleeves nesting end of (9, 10) blade spars marked with red lines. Main rotor control rods (13) hinges and (14) pushrods can increase pitch of rotor blades sliding up/down in the holes of (15) rotating drive disc. Lower tip of pushrods pushed down by (8) torsion spring slide on (16) non-rotating swashplate, which is here really just a plain plate with a hole in the middle letting through main rotor axis (this way I could resolve lack of large diameter bearing and ball joints). Swashplate can be tilted around main rotor axis in any direction on (17) double hinges by (18) cyclic control levers, resulting cyclic change in pitch of blades. Swashplate be can lifted/lowered by (20) collective lever through (19) collective pushrod resulting collective change of pitch of blades. Collective lever What you cannot do on computer - Dirty building trick 1: as (19) collective pushrod lifts swashplate asymmetrically from backward against the foce of torsion spring, it would twist it forward also, which would disturb cyclic control. So collective pushrod is built in twisted backward to counteract it. This way, collective lever lifts swashplate perfectly leveled. (21) main rotor gear is driven by (22) main rotor transmission shaft running down on right side of main rotor mast. Rotor blade Dirty building trick 2: Rotor blades are the most controversial part of my design. I assumed that sticker sheet of decals provided to set 8051 is not pre-cut, but can be used in 2 large rectangular pieces to cover main rotor blades (I used transparent duct tape with the same area to simulate this). Why? I simply got fed up with that Lego cannot provide us reasonably aerodynamic rotor blades. They introduced specialized rotor blade component at set 8046 in 2010 but they put studs in the middle of it making it pretty ridiculus. Another sad example is SgtPepper’s Aerospatiale Alouette II design from 2008 (see: AlouetteII ). This guy made incredibly realistic machine, but he had to put studded bars in the airflow as rotor blades Therefore I make a recommendation: Dear Lego Technic Guys, you should introduce a set of standard sized transparent/colored stuctural decals which can be used as skin/cover/window on light vehicles – just like the very succesful set of fairing elements introduced 10-12 years ago. Advantages: -Decals are already well-known technology for Lego being part of many sets -They are cheap and comply children safety rules as long as they are not enogh big that kids can strangle each other with that -Larger areas of cover can be sticked together from smaller standard parts -Duct tape material technology made serious improvement in recent years using high tensile strenght plastic foils, water-resistant glues, sticky surfaces renewable with simply washing it with detergent, stretchable foils keeping their shape, etc. -Combining decal covering with stiff/elastic rod structures would provide excellent modeling tool for real world’s welded steel/dural tube stuctures covered with glass/carbon fiber reinforced resin: eg. most racing cars, rigid wing aircrafts, hoovercrafts, light ships, etc. -Mildly curved surfaces eg. windscreens of cars/planes could be modelled with ease Building rotor blades, I used the 4 “claw” components provided in 8051 as wing profile griders covered with decal. It is still very far from a patented NACA (National Advisory Committee for Aeronautics) -aerofoil section, but it made its effect. When I prepared the open-air photos of Helichopper, there was medium wind, and blades did what they are proposed to do with annoying flipping-flopping. (And Dear Lego Guys, when you will design the claws of the next Godzilla/ Tyrannosaurus/ Alien/ Lady Gaga set, can you accidentally use the shape of NACA 712A315 aerofoil, thanks.) 5.Tail rotor If I build it from scratch, I use two separate sets of cardan axises+universal joints+clutches for rear wheel/tail rotor alongside rear left/right fork. But in 8051 set there was not enough axises for this after building rotor blades. Moreover, it would require coaxial layout of rotor and rear wheel hub, and components of coaxial axises are weak point of Lego Technic. I tried to separate rotor and wheel drive on left and right half-axises, but it undermined the structrural strenght of rear fork. Finally, I fixed rear wheel and rotor on common axis driven by chain. This way, rear wheel has to be lifted from ground in helicopter mode by the retractable landing gear, allowing it spin fast as tail rotor. This is not very practical and clearly dictated by material limitations: At rough crash-landing, landing gear may collapse and fast spinning rear wheel may suddenly touch ground, flipping over Helichopper. A spinning fan before standing rear wheel reel blades would be also more effective aerodinamically. There is only one advantage of this forced solution. Fast spinning rear wheel acts as a flywheel increasing rotor inertia, which is critical for survival in dead engine autorotation crashlanding, reducing „dead man zone” (combination of low height and low horizontal speed insufficient for autorotation). Extra momentum of rear wheel does not influence badly maneuverability of rotors, as usually in most rotor systems, constant rotor speed is maintained by electronic engine throttle governor and all controls are done with altering main/tail rotor blade pitch. Let’s see tail rotor components more detailed: shorter type of fairing elements are used as (2) tail rotor blades, wich can be pitched around axis of (1) tail rotor hub peripendicular to rear wheel axis. Left-right movement of (3) flanges and (4) cotrol rods driven through rear wheel hub holes regulates their pitch. (4) control rods are held by (5) rotating slide, whose left-right movement is controlled by (6) fork of pitch control arm. The arm can be rotated around (7) axis by control cables running below left rear fork. Rear wheel axis is driven by gear shift through chain. Rotating point of (15) rear fork is so close (2 studs) to gear shift axis that fork movement in normal range does not influence chain tension seriously.   6.Engine and gear shift (8) gear shift axis can move 0.5 studs right and left shifting between high gear (equal sized flat gears on left side of engine) and low gear (different sized (8, 9) bevel gears on right side). The chain has enough flexibility allowing this small side movement. Dirty building trick 3: In the reality chain drive gears have conical teeth, this way they can tolerate pretty well if they are not perfectly aligned in line with chain. However Lego did not develope specialized chain drive gears and chain can jam on flat gears if they are not perfectly aligned. But, if we deploy chain reversed compared to 8051 building instruction (chain member hooks outward instead of inward), tip of gear teeth will meet rounded edge of chain members and jamming tendency will be reduced. In flight mode, the (10) lower bevel gear of main rotor transmission shaft connects to (8) large bevel gear of gear, locking gear shift in low gear. (13) spring of rear suspension is placed between (8) gear shift axis and (14) rotating axis of main rotor mast to save space. The placement of the horizontally opposed, 2-cylinder, 2-stroke, liquid cooled, Rotax-style engine before rear wheel is unusual at choppers, being more common in scooters. But it has serious cause: COG (Center Of Gravity) of the craft should be resided under the main rotor axis, therefore the relatively heavy engine is placed behind it, to counterbalance weight of fuel tank, forward fork/wheel and armament/ammunition. Pilot’s weight does not influence COG seriously, as he/she is positioned almost directly under main rotor axis. In road mode, gear shift axis is shifted left-right by (11) gear shift rod pulled by (12) gear shift cables. Rotor mast is locked in open position by (14b) backward foldable grider strut and (14c, 14d) locking pins.   7.Landing gear and yaw control pedals Landing gear can be lowered - to get rear wheel free spinning as tail rotor - by pulling (13) lever towards front edge of seat. However, it would be impossible to lift the whole rear part of the craft by this lever with manual force. Therefore, there is a scissor-mechanism under the middle part of seat consisting of 2 jacking hinges (14, 15) joined to (17) pin. Pulling them upward by (16) lever provides sufficient force to lift rear part of the craft and locks landing gear in lowered position. (12) gear shift cables run through (18) flange and (20) bowden towards left horn. (21) fender of front wheel prevents mud spilling from wheel clogging (19) coolant radiator. Echeloning movement of (22) yaw control pedals is governed by (23, 32) echelon-positioned arms rotating in (24) flange, which is fixed on (25) axis. The axis can slide forward/backward in (26) slide fixed to main frame, pulling either (28) control cable anchored to (32) arm, either (29) cable anchored to (27) arm with (31) pin. (28, 29) control cables run backward above crankshaft of engine, then through (33) lead to reach tail rotor pitch control arm rotating on rear fork. 8.Forward fork and horns By default, front wheel and fork would not play very important role during flight. However, I use it as a virtual „gun turret” allowing (39) 7.62mm machine gun mounted on forward wheel axis to lay from -60 to +60 degrees horizontally, and train from -30 to +60 degrees vertically. Horizontal laying happens simply by rotating horns, vertical training is made by depressing/raising (37) train lever, through (38) training rod. Leftover part of chain is used modeling (40) ammunition belt, which is rolling down from (41) running gear of ammunition drum built behind left headlight. (42) ammo belt brake lever locks belt moving it to right and release belt moving it to left. Moreover, moving (42) lever up and down can raise/depress headlights, because in flight mode headlights are used to illuminate/blind targets on the ground. As axis of gun barrel does not match axis of rotation of fork, recoil force of the gun will generate torque on fork wanting to turn it to right. As it is very hard to counterbalance manually, pressing (43) button can lock forward fork in a given position forcing a rod among the teeth of a bevel gear fixed to main frame. Fork lock is also used during autorotation crashlanding, when forward fork can be hit hard, to prevent its jacking. On most bikes gears are shifted with a pedal, but here pedals are used for yaw control. So (34) gear shift lever is placed on left horn, pulling gear shift control cables running trough (20) bowden. (36) brake lever is placed on right horn, pulling brake cable through (35) brake bowden fixed to (44) brake assembly. The cable pulls (45) brake arm, which presses a shorter arm to (46) brake disk. 9.Transition process between road and flight mode -(34) gear shift into low -(13) landing gear down -(16) landing gear locked -(43) forward fork locked -Open rotor blades and lock them into (4, 5) sleeves -Open main rotor mast -Open (14b) main rotor grider strut and lock with (14c) locking pin -Lock (14d) locking pin -Spin up rotors to standard speed -Raise collective lever, etc. 10.Leftover materials Set 8051 was a good source of material, in this sense, it was value for money. Moreover, altering model scale from 1:6 to 1:10 helped to create much more functionality from the same amount of material. Even we have some stuff left over: 11.Unsolved problems and shortcomings -Main/tail rotor gearing ratio is 1:1: this is serious shortcoming as it is 1:10 in reality, or in case of high rpm fenestron tail rotor 1:20. The reason is that gear shift has very limited space, and 8051 had no special gear shift components, so I could not solve building there more high gear levels spinning tail rotor more fast. -Collective control levers work 90 degrees rotated: tilting them forward causes right roll, tilting them right is backward pitch, left is foward. This is because reverser rods has no space left in main rotors constrained size, and 8051 lacked necessary ball joints -Incorrect Center Of Gravity: in most rotorcrafts, COG should be uder main rotor axis, while here we have it 2 studs/0.16m/6.4” forward from that. But in the reality, engine placed back side of main rotor axis is more heavy than wheels, so this problem will solve itself by engine placement. Weight of pilot will not seriously influence COG position, as pilots most weight resides directly under main rotor axis. -Engine is not connected to rotor drivetrain through centrifugal clutch: in the reality, road/flight modes would require 2 different type of clutches: road requires conventional manual clutch allowing use of engine braking. While in flight mode, a centrifugal clutch should immediately disengage engine from rotor drivetrain if engine rpm suddenly falls. This prevents a stalling engine destroying rotor momentum, which is key factor of survival at dead-engine autorotated crashlanding. 12.Acknowledgements -Name „oTo” comes from the name of Otoe American Indian tribe. This Sioux-originated tribe originally resided at Great Lakes but in 1884 they were deported in Oto Reservation Nebraska. My design is a tribute to them. -Thanks to my wife, Cathy not divorcing me during 10 days of continous Lego Tech-narcosis developing oTo Helichopper

Dear Grindinggears, Thanks for the reply. I have the following comments on your concept: 1. Yes, batteries may not be enough ballast weight for large and deep draft hulls. We can think about a stuff as ballast being: - cheap - heavy - worldwide standard in size and weight - accessible in any DIY store - has multiple smaller units to adjust ballast gradually - flat to bring Center of gravity as low as possible - can be fixed on hull section bottom to prevent sliding Maybe, plaster fillup of section bottom can work as large ballast: vailable everywhere packaged as powder, its non-toxic and it needs only water, when filled and dried it sticks to polypropilene parts of LEGO, but not too strong 2. Current LEGO PF motors has fair protection against spilling water, but electric connector parts are not. They should introduce some water-resistant connector boxes and cable plugs 3. I disagree with your "make the whole hull strictly watertight to prevent short circuit"-concept. Why? Its expensive and ineffective: - Real watertight stuff, which resists not just spilling water, but some water pressure (eg. pressure of 0.1-0.3m of water, which is 0.01-0.03 bar) require rubber or silicone sealing rings AND screws or VERY STRONG clips and cannot be made with usual LEGO polypropilene mold parts - Some perverse guys would like to sink the enemies RC ship in a battle, so hulls should be opened to water anyway - At battleships, it would be hard and expensive to solve water resistant sealing of rotating gun turret platforms (gun turrets usually intrude downwards into hull through decks) So my concept is get prepared that electric system WILL BE SOAKED ANYWAY. I would place a main circuit breaker in the watertight, pressure resistant and sealed battery rack, and 3-4 circuit breakers defending most important subsystems (engines, RC, lighting, gun turret servos). All other electric components would be only spill resistant, but not pressure resistant, so they can be cheaper. 4. About propeller shaft outlet on hull: a regular tecnic hole cannot be sealed to resist water pressure, especially using regular technic axises. The outlet should be a self contained unit screwed into hull wall, being diassemble for normal user and containing: - short piece of polished metal shaft (similar to old LEGO wheel axises) with regular technic shaft extenders at both ends - on the metal shaft, there should be a silicone simmering, whose compression can be adjusted by a bolt (fixed by contra bolt) as function of its wear. - From shaft outlet, separate extarnal shaft would run to the propeller, and separate internal shaft to the engine - I would place 3 shaft outlets in aft hull section: it is enough for most historic ships (some battleships had 5 or 4 shafts, but this simplification would be usually underwater and nobody would notice it) 5. I would not intend LEGO ships for open water, just in pools. LEGO - even with the proposals above - is not a level of technology suitable for open water - sooner or later it would be nice and expensive gift for the fishes... Rescuing ships with dead battery or RC from a pool - if you do not want to get wet - is the easiest with another RC ship, if there are some standardized rescue clamps on hulls to tow each other

1. 316-type hull was pretty nice, I loved as a kid (if you put there enough ballast in that), just this is the rescue boat in minifig scale, not the ship... 2. 7075 seems to have one piece hull. Are you sure? 3. Very big is 78cm long. Considering 1:36 minifig scale, it would be around 27m long in reality. Thats is reasonable size for tugboats, but tragically small for any sea-going ship, even strongly downsized. A large modular floating hull with suitable ballast is definitely missing from LEGO product lines. Also, it would be an excellent business for LEGO pulling out more money from peoples pocket: - I would sell the hull with minimal, light upperworks, without power functions (just with propellers and shafts) to keep it reasonably priced, to trap the guy - I would sell inflatable basin as separate accessory - I would sell power functions as separate accessory: battery rack at keel would play as ballast for heavier upperworks - I would sell extra middle hull section modules as separate accessory for those whoever want to make longer ships - This would also generate sales for basic bricks as increasing hull size will dramatically increase material requirement, but bigger upperworks are much more spectacular - I would organize a web-competition for rendering historic ships to motivate builders - I would ease on LEGO policy "no actual war macinery" a little bit, because battleships are the most spectacular LEGO ships ever. As current modern warships start to resemble floating black coffins because of stealth technology (think about USS Independence class), I would let issuing sets until end of 1970s battleships (eg. AEGIS-cruisers like USS Vincennes, etc.) as they are already historic and will phased out from active service very soon.

1. Very serious counterweight. Can it be more than 50 grams? 2. Simple LEGO for simple kids? I hope my kids will be little more complicated... Anyway, market will decide: if Chinese competition will knock out LEGO in those product lines within some years, then I had the right, otherwise all other LEGO fans.

1. In earlier posts we already cleared that flyable micro helis would require downsizing current Technic part into at least 1:4. That would mean a completely new product line LEGO would not jump into. 2. About making non-floatable hulls floatable: When I rebuilt my corvette from 102cm hull made by BanBao, I had the idea of filling the hollow space inside with self-expanding isolator polystirol foam can be purchased in any DIY shop. Finally I did not make it. Why? Floating is one thing, stability is another. Classic lego bricks even in minifig scale are pretty heavy even for upperworks of ships resulting hard topweight problems. If I were a LEGO develepoer how I would solve it (assuming that marketing and sales guys would not block me): - Floatable hull made of 4-5 stepped sized sections with 1.4-1.6 m total lenght, which can be embedded into each other when packaged like flowerpots, resulting 0.5m box size - Bow section should have a replaceable nose keel, enabling to make clipper bow (basic setting), vertical bow (like Titanic), bolbous bow (Modern freighters), ram bow (ironclad battleships) - Stern section should have 2 propeller shaft exits sealed with simmerings, and a detachable aft hub allowing to build both flat or rounded stern - I would cheat a little bit with beam/chord ratio. At most seagoing sigs it is from 1:8-1:10, but I would make it beamier 1:5-1:6. It improves stability and as LEGO ships usually do not have to make several thousand nautical miles in your bathtube, increased drag is not a really big problem - Also cheat a little bit with draft/beam ratio. In the reality it is 1:3 to 1:5 enabling ships to pass shalow water. I would increase draft to 1:2 or even more - I would use a watertight flat rack for A type batteries as ballast in middle section to set optimal draft for stability: 4 A batteries would be connected serially to make 6V in 1 row, and several rows of batteries in rack would be connected parallel. This way you can increase decrease ballast weight with quarduples of A batteries to get optimal settings. For longitudinal stability, you could move the battery rack on keel forward and backward - Battery rack should have a circuit breaker to shut off all electricity if electric system gets soaked - All sections should have 3 plugs (2 at sides and 1 at bottom): pulling them out, leak can be simulated With this variable hull, you could build wide range of modern commercial/navy ships using classic lego bricks as upperwork I think this would be a solution of your problem, not styrofoam or ping-pong balls

Then all other companies manufacturing wide range of flying helis for kids (usually recommended above age of 12-14) ceratinly have much better lawyers than LEGO. Because they can survive despite masses of decapitated kids by rotor blades... Seriously: can anybody attach at least 1 link about serious injury caused by micro-helis?

I'm continously collecting here list of mechanically most realistic helicopters from Brickshelf. Grading bases of my subjective judgement ranging from 1:Bad..5:Excellent: - Aerospatiale Alouette II, Exact, 2008, SgtPepper, >LEGO Tech figure scale, Mechanics:5, Innovativity:N/A, Realism:5, Gallery - UH-1, Lookalike, 2000, Roscohead, >LEGO Tech figure scale, Mechanics:5, Innovativity:3, Realism:3, Gallery - UH-1D, Exact, 2007, Scottbase, >LEGO Tech figure scale, Mechanics:5, Innovativity:N/A, Realism:4, Gallery, Pneumatic drive??? - UH-1, Exact, 2010, Scottbase, >LEGO Tech figure scale, Mechanics:5, Innovativity:N/A, Realism:4, Gallery, Electric drive - Bell Jet Ranger, Exact, 2008, Luh2000, >>LEGO Tech figure scale, Mechanics:5, Innovativity:N/A, Realism:4, Gallery, Electric drive??? - Bell Jet Ranger, Exact, 2005, Nparvin, >>LEGO Tech figure scale, Mechanics:5, Innovativity:N/A, Realism:4, Gallery - RAH Comanche, Exact, 2005, Nparvin, >LEGO Tech figure scale, Mechanics:4, Innovativity:N/A, Realism:5, Gallery - Westland Wasp, Lookalike, 2009, Sai, >LEGO Tech figure scale, Mechanics:5, Innovativity:4, Realism:4, Gallery - Sikorsky Sea King, Lookalike, 2005, Pierrick, >LEGO Tech figure scale, Mechanics:5, Innovativity:4, Realism:4, Gallery - Eurocopter Gazelle, Exact, 2006, Wojtek, >LEGO Tech figure scale, Mechanics:4, Innovativity:N/A, Realism:5, Gallery, Electric drive, Unfinished - Banshee tiltrotor, Custom design, 2011, Drakmin, =LEGO Tech figure scale, Mechanics:4, Innovativity:5, Realism:4, Gallery, Electric drive - Avatar tiltrotor, Exact, 2010, Barman, =LEGO Tech figure scale, Mechanics:5, Innovativity:N/A, Realism:3, Gallery, Electric drive - Eurocopter Dauphine, Exact, 2003, Samrotune, >>LEGO Tech figure scale, Mechanics:5, Innovativity:N/A, Realism:4, Gallery, Pneumatic drive - Eurocopter Squirrel, Lookalike, 2011, Gjpauler, =LEGO Tech figure scale, Mechanics:?, Innovativity:?, Realism:?, Gallery (Thats me, so somebody else should grade that) We also have to mention models of RalphS, who makes all kinds of military choppers in 1:36 minifig scale. They do not have any real mechanics but airframes are incredible: - AH-1: Gallery - AH-64: Gallery - CH46: Gallery - CH-47: Gallery - HH-1N: Gallery - Dolphin: Gallery - MH-53N: Gallery - MI-24: Gallery - SH-60: Gallery -Sea King: Gallery Other very realistic airframes without real mechanics: - AH-64 Apache, 2008, CombatM, Minifig Scale: Gallery - Eurocopter EC145, 2011, Darkenski, LEGO Tech figure scale: Gallery

You are absolutely right. There are bounch of very proficient builders making upperworks of battleships/cruisers almost like real even building smaller than minifig scale (I remember HMS Sheffield, USS Indianapolis, etc.) but they usually come into serious trouble regarding the hulls: - Build from bricks results in quite a "cubistic", faceted hull - Then they grab the good old hot air blower and start to slightly curve plates, and glue them, which is not really authentic LEGO building method... Only very large, 4-5m long hulls look reasonable made from unspecialized bricks (Yamato, HMS Hood, USS Harry Truman, and I remember a large cruise ship), even they cannot swim. Current swimming lego hulls are joke topping the mighty, tremendous, mind-busting 45 cm lenght without any propellers It would not require any high tech and new materials creating even a 1.6m long swimming hull from 4 or 5 sections (aft section would have 2 propeller axis exit sealed with simmerings). With carefully stepping section sizes they could be embedded into each other -like flowerpots- at packaging, resulting reasonable 40-50 cm box size. Longer hull than 1.6m would be hard to sell as it cannot fit a standard bath tube... (not everybody go to a lake or pool everyday). As an accessory a 2m rounded inflatable basin of 0.15m deep could be sold separately. LEGO is quite a passive in this area, which is strange, because large LEGO ships are very spectacular, as classic lego is pretty suitable to make upperworks, gun turrets, masts, etc. One of the relatively better quality Chinese copiers, BanBao issued in 2010 a battleship with 102cm non-swimming, but specialized hull, where there are 8 identical body sections between 1 piece bow and stern. The hull is pretty good, upperworks design is terrible, but it is a good source of material to build a corvette carrying 2 helicopters in minifig scale. Tolerance of their parts is around 1.25 times of LEGOs, which is not really good, but quite an improvement as they started with 2-2.5 times, which was almost useless.

Child safety is a serious issue as I already mentioned in the opening post. Thats why main rotor heads, flybars, rotor blades should be highly customized parts, being impossible to build together with anything else which can fly off from them directly into someones eye. Using self-contained "flying cores" with customizable airfarame can address the problem. But anyway if 20 grams is dropped on your head because you made incorrect design: its worth to try, maybe you will survive and learn from that... Originally LEGO's purpose was not just entertaining "droids" incapable of even the slightest innovative thinking (First Person Shooters are pretty good for this), but challenging kids to extend the limits of their creativity. And it is a learning process when you sometimes fail and then you try again...

I agree with you that flyable parts would mean a big shift (like between classic and Technic lego) and a completely different product line. This is a story where LEGO definitely would not jump into easily: - In my estimation, for "flying cores", Technic parts should be downscaled 1:4 and made from more expensive light alloy or glas fibre reinforced epoxy instead of current polypropylene/poliethylene mold, connected with metal screws (see mini electric RC helis of BuzzFly in UK as a fair example) - Customizable airframe parts could be something similar to Revell clip-it kits But what if those tricky Chinese guys come up once with a police station/rescue ship/trailer truck (all classic profit generator LEGO Themes with helicopter) where the helicopter can fly a little bit (incompatible, but spectacular way)?