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8068 Rescue Helicopter discussion

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Here's a video of the rescue helcipter (8063) being built by JunkstyleGio:

Edited by Zblj

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The white panels and rear-rotor hubcap that Blakbird is talking about are shown in this picture of the 1H2011 Lego Technic 8068 Helicopter set (from Tony_st170's high-resolution pictures on this Eurobricks post):

003.jpg

Edited by DLuders

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I'm debating whether or not to buy this. It looks great, and I like the white pieces. However, I'm disappointing that a helicopter in this price range has fixed rotor blades. I think I'll wait and see what comes out during the 2nd half of year before making a decision. I do really like the appearance, especially the B model. :thumbup:

Edited by dhc6twinotter

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Remember this is a mid-range model with only 408 parts with 50 connectors.

Moving rotorblades would be a big thing to incorporate without loosing its looks. It is strange that the rotors have a 1:1 ratio. That should have been otherwise.

Still, this set is a great addition to the line of choppers and for the kids a great follow-up to last years small helicopter.

8068-8046.jpg

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Remember this is a mid-range model with only 408 parts with 50 connectors.

Moving rotorblades would be a big thing to incorporate without loosing its looks. It is strange that the rotors have a 1:1 ratio. That should have been otherwise.

Still, this set is a great addition to the line of choppers and for the kids a great follow-up to last years small helicopter.

Very well said. I love the looks of this model and the B-model as well and I am pretty satisfied with its functionality (Working doors or so would be great). Maybe if the colour scheme was yellow/blue I would be more satisfied, but it does not change the thing that I cannot wait to get this set. Any helicopter/airplane is way better for me than an excavator.

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Remember this is a mid-range model with only 408 parts with 50 connectors.

Moving rotorblades would be a big thing to incorporate without loosing its looks. It is strange that the rotors have a 1:1 ratio. That should have been otherwise.

Still, this set is a great addition to the line of choppers and for the kids a great follow-up to last years small helicopter.

True, however the 8412 Nighthawk and the 8444 helicopter had moving rotor blades. If I remember correctly, both of these sets were less than $40. Maybe Lego's mold for creating those unique swash plate pieces no longer exists. :sad:

That aside, I think it is a great looking set. I didn't realize it was so much larger than 8046. Thanks for the photo! :thumbup:

Edited by dhc6twinotter

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True, however the 8412 Nighthawk and the 8444 helicopter had moving rotor blades. If I remember correctly, both of these sets were less than $40. Maybe Lego's mold for creating those unique swash plate pieces no longer exists. :sad:

That aside, I think it is a great looking set. I didn't realize it was so much larger than 8046. Thanks for the photo! :thumbup:

All 3 sets to feature the "Technic Propeller 4 Blade 7 Stud Diameter with Square Ends" (which is the special swash plate piece in question) also used the now-discontinued Flex System to control said swash plate.

Maybe the number of parts required to bring the swash plate out of retirement is too great.

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Well that was easy!

replacing one gear and removing one half bush and the front-rear rotor ratio is to 1,66:1.

8068gearchange.jpg

@ jonwil:

Yes the the retracktion of the wheels are operated by the lower 12t double bevel gear.

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Finally I got mine. Thank you JunkstyleGio for the simple modification of the rotor gear ratio.

p1160982.jpg

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True, however the 8412 Nighthawk and the 8444 helicopter had moving rotor blades. If I remember correctly, both of these sets were less than $40. Maybe Lego's mold for creating those unique swash plate pieces no longer exists. :sad:

That aside, I think it is a great looking set. I didn't realize it was so much larger than 8046. Thanks for the photo! :thumbup:

I really like this Set... Nice thingy. :wub:

Moving rotor blades for $40.. these were other times...

while studing the catalogues you´ll notice over time... functions as well as parts cut down a bit year by year.

its like chocolate... fewer nuts and smaller bars for increased prices :cry_sad:

In this price range its the best set compared to 8048 or 8262 to me,

and finally we get more than a hand full of nice white pieces again.

i am totally sick of yellow, red and black,

so i am happy this set and the coming 8073 bucket truck is a source for white beams and panels. great. :classic:

Lets see if we get some lime and more blue again 2012...

The only thing i don´t like in design is the "windscreen" flex-hose, which looks weird this way.

It should have better started at the end of the red frontpanels.

Tom

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Yeah, I put the flex axle through the connector between the panels and it looks slightly better. I did not like the former version as well.

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I like this set very much. I missed out on last year's Helicopter (sadly :cry_sad: ), and this seems like an adept replacement.

I hear that there were some helicopters with tilting rotors before, but I am okay with this not having that function. However, I am not okay with a sticker on every single panel. "How would that look on the alt. model?" I ask myself. May someone who has this (w/stickers applied) post a pic of how the alt. looks?

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I built this set a few days ago and it is a very nice model. I also bought a few others for parts :classic:

Edited by TechnicJuan

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Slovakian AFOL "LUGSK" posted this short

of TLG's 8068 animation. He wrote, "With this very realistic looking helicopters can perform daring aerial rescue. Move chainrings ensure simultaneous rotation ..."

Edited by DLuders

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When I first saw 8068 Rescue Helicopter – being both LEGO Technic and helicopter addict – there was a definite „Whao effect”: finally a realistic looking LEGO chopper!

At the first sight, both in shape and colour scheme it strongly resembles to Eurocopter (former Aerospatiale) Dauphine used by US Coast Guard. However not an exact copy: unlike the original, here engines are before main rotor mast (more like Aerospatiale Puma) and airframe is „pod and boom” instead of being fully faired. I guess it was very intentional, to avoid licensing problems with Eurocopter

In the history of LEGO Technic helicopters, this is the 3rd-4th serious attempt to model a real helicopter. (You can find an excellent summary about their history at May 2011 archive of LEGO Technic Designers Blog It has no pictures, but you can easily hunt down pictures from Internet):

- 8844 dated in 1981 resembled an early Bell Model 47 with tailwheel tricycle landing gear

- 8456 dated in 1996 had some slight similarity to AH-1 Cobra

- 8444 dated in 1999 resembled Eurocopter Tiger (without weaponry)

- 8068 today: Eurocopter Dauphine/ Gazelle (2nd version)

Thus the strong point of 8068 is the airframe, especially because of retractable tricycle landing gear, which has a fairly compact mechanism in the cabin floor.

Less successful but still acceptable features are:

- The seats: they are too big for minifig scale, too small for LEGO Technic or even Belleville figures. Correct scaling to the latter ones would make the chopper too big requiring more parts and resulting higher retail price. But moderate upscaling of seats and cockpit doors would have made 8068 more usable.

- The rescue winch: it has no crane arm unlike the reality, so poor rescued guy will be shattered at the edge of cabin floor during lifting…

The weak point of 8068 is very clearly the dynamic system, which is rather primitive for a medium sized Technic model:

- Monobloc 3-blade main rotor: Ironically, the very first LEGO Technic helicopter 852 dated in 1977 had the most realistic working 2-blade, variable pitch Bell-rotor with collective controls connected into cockpit. However it was big and clumsy because of the lack of specialized parts. (About working of helicopter rotors and controls, see April 2011 archive of LEGO Technic Designers Blog) Since that, LEGO never attempted variable pitch blades. 8856 in 1991 introduced a specialized swashplate part, which enabled cyclic control of main rotor, however in a rather unrealistic way: the whole rotor - forming one monolith unit - was tilted on main rotor mast, which is practically unworkable. Even this simple stuff was not used after 8444 in 1999.

- Non-connected controls in cocpit: 8412 in 1995 was the last model with cyclic controls connected in cockpit

- Main/tail rotor gearing ratio is 1:1: this is a common mistake of all LEGO helicopters, as this is usually around 1:10 in reality. Earlier posts showed that this can be raised to 1.6:1 at 8068 switching gears

- Gas turbines are not connected with drivetrain

- Hubcap?! instead of Fenestron tail rotor: Fenestron is a small diameter, multi-blade, variable pitch, ducted fan tail rotor invented by Aerospatiale and used first on Gazelle. It gives the advantage of reduced noise, less drag, and less vulnerability (modern examples: Eurocopter EC-135, RAH Comanche). Replacing it even with a fixed fan propeller would be a strong simplification, but LEGO used here a hubcap of a large diameter wheel: if you see carefully, one blade has negative pitch, the next one has positive, and so on: thus air goes nowhere from this! This is very crude mistake, considering that quite a realistic looking fenestron (and Eurocopter Dauphine) was built from classic LEGO parts, however in somewhat bigger (1:36) scale (see: acidcow ). Moreover, none of the LEGO Technic helicopters has variable pitch tail rotor at all. In the reality, this little tail rotor hub means the difference between life and death.

Of course, it is very easy to criticize someone else’s design. Therefore, in my next post, I will show that all these problems adressed above can be solved using parts solely from 8068 Rescue Helicopter. And even we do not need the hubcap…

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Building more realistic helicopter from 8068 Rescue Helicopter

I built a Light Assault Helicopter solely from the parts of 8068 with 4 seats, single engine, 2 side gun pods, 4 channel realistic controls, resembling a mixture of Eurocopter Squirrel and Hughes Defender

Main rotor:

It was the biggest challenge. As size of LEGO Technic small mechanic parts (hinges, joints, flnges) are still pretty big compared to the scale of LEGO Technic figures, the hard thing is to build SMALL AND REALISTIC rotor. So I selected the simplest possible main rotor: 2-blade Hiller-type with flybar used on most RC model helicopters.

(Technical note: Flybar is a pendulum-like device fixed with cardan-hinges to main rotor axis transversal to rotor blades. It was invented by Robert Young (Buffalo, NY) in 1946 and used first at Bell Model 47. It acts as a stabilizing device: it tries to keep its original plane of rotation because of 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 swashplate, and only the flybar controls main rotor blade pitch. It has the advantage of increased stability over the Bell-rotor, where the pilot directly controls collective and cyclic pitch of rotor blades trough swashplate. Its disadvantage is less responsive control, so there is a mixed system called Hiller-Bell, which is stable AND responsive but mechanically more complex)

To create such a thing we need 3 critical specialized parts: 1 swashplate (a large diameter bearing with ball joints), 4 ball joints for control rods, 1 cardan hinge slideable on main rotor axis. Of course 8068 had none of these stuff, so the real challenge was further simplification of Hiller-rotor without loosing its functionality

- Building a sliding cardan-hinge would be theoretically possible from 8068 parts, but its size would make the whole rotor ridiculusly bulky. So I omitted the whole thing, and flybar really „flies” around main rotor axis, wich has a single ring closely rounded by flybar hub components. So flybar can tilt in any direction around main rotor axis and can be lifted and lowered vertically. But how it will stay strictly transversal to rotor blades once it is not linked directly to main rotor axis?

- The solution came from a limitation: total lack of ball joints. Thus, both control rods have two simple hinges at their both ends tilted by 90 degrees, and 2 hinges can slide on flybar rod sideways. This allows all necessary movement of flybar but keeps it transversal to rotor blades.

- As there was no any large diameter bearing for swashplate, I built reels of 2 original landing gear wheels into the flybar hub as rollers on half-axises longitudinal to rotor blades. Swashplate here is really just a plate under rollers with a hole in the middle letting through the main rotor axis. Plate can be lifted and lowered for collective controls: it lifts flybar hub through rollers, which increases pitch of blades through control rods. The short red elastic rod on the top of the rotor (everybody believes that it is a clamp to lift the helicopter by crane…) acts as a torsion spring decreasing blade pitch gently pushing flybar hub rollers against swashplate. Also the plate can be tilted longitudinally or transversally for cyclic control: it changes the tilting of flybar hub, which will influence its plane of rotation, which provides cyclic blade pitch control through rods.

- Collective and cyclic levers go in the cabin roof from swashplate forward to cockpit, where vertical bars running behind the front seats connect them with collective and cyclic control arms placed between front seats

- I omitted flapping and dumping hinges ususally connecting rotor blades to main rotor hub in Hiller system, but their attachment looks like bearingless „elastomer” joints of more modern rotors. In turn they are foldable by 90 degrees making the helicopter storable in compact spaces.

Tail rotor:

Theoretically, a variable pitch tail rotor should be a more simple story than the main rotor, but it wasn’t. Small size requested and lack of swasplate were the limitations again:

- Tail rotor hub setting pitch of 2 tail rotor blades with short control arms can slide on tail rotor axis sideways

- A 90 degree joint acts as pitch control arm, pushing a roller (made from reel of 3rd original landing gear wheel) to tail rotor hub forcing it sliding forth and back on tail rotor axis

- Tail rotor blades are made from shorter type of fairing elements, which are quite aerodynamic: quickly turning tail rotor they make reasonable wind, and this is what we want…

- Tail rotor transmission shaft and pitch control rod run along tail boom under the longer type of fairing. I found good use of the thin long black flexible rod given to 8068 leading control rod through fairing, so it is fully covered giving more clean lines to the helicopter

- Jaw pedal controls are before the left forward seat. Their reversed movement is ensured by triplet of gears. Unlike real helicopters, jaw control rod runs backward in the cabin floor to avoid big „crowding” around main rotor mast. Behind left rear seat, under the fairing, there is a hinge transmitting jaw control to control rod running parallel with tail boom

Drivetrain:

- Single engine is placed at the tail of cabin under tail rotor transmission shaft covered by fairing. It is geared 1:1 to main rotor axis and 1:1.6 with tail rotor shaft. Air intakes are at the top side of tail boom

- The 3-part tail rotor transmission shaft is very mildly curved enabling to match gearing

Airframe:

My intension was to creat very compact cabin like Hughes Defender but having 4 seats capable of accommodating 4 LEGO Technic or Belleville figures (or 4 Playmobil figures – oops, thats another company…).

- This was done maximally utilizing flexible bars and fairings (8068 is good source of these) shaping the cabin.

- Vertical part of seats are also griders of the airframe to save space and material.

- As forming the cabin tail cone of Hughes Defender proved troubleful from available material left and collided with the placement of the engine, moreover the 4-seat cabin became slightly bigger, the final airframe more resembles to Eurocopter Squirrel (earlier called Aerospatiale Ecureuil), except that it has the engine under tail rotor transmission shaft covered by fairing like in the Defender.

Other parts:

- Instrument panel: virtually unchanged from 8068

- Weaponry: 2 side machine gun pods with variable elevation built from 4 left over fairings and 2 rods similar to Hughes Defender

Summary:

8068 was a good source of material for building much more realistic, but somewhat smaller helicopter, even some valuable stuff is left over (1 gear, 1 rotor blade, 1 fairing, etc.). What I could not solve because lack of material:

- Cyclic control arm works reversed compared to real helicopters and controls only forward-backward pitch, but not rolling: the swashplate can tilt transversally, but not enough rods, joints hinges are left for roll control

- Gearing ratio between main rotor and engine/tail rotor is not enough big

LEGO Technic Helicopter future and recommendations:

The big question is: Will LEGO Technic helicopter ever lift off the ground? Even just some years before this idea looked totally sci-fi, but recent advancements in mass producing of cheap, simple electric helicopters makes it actual. In my vision it depends on following conditions:

- Developement of aerodynamic, auto-folding main/tail rotor blades: technically, it is not a big issue (Why the hell 8068 has dots in the middle of the rotor blades??? No one wants to fix there anything!), but children safety issues are serious, especially in USA, where anyone can sue anybody for anything for at least a million dollar.

- Developement of on board Li-polimer battery rechargeable from USB port of iPod, laptops, etc.

- Developement of smaller sized, brushless motors with adequate cooling (built in fan with vents)

- Developement of set of thinner, high tensile stenght, glass-fibre reinforced rods as shafts and structural airframe parts, with siutable sized ball joints and hinges. Child safety issues will occour.

- Introducing mini metal-plastic screws for vibration resistant and compact joints. Child safety issues will occour.

- Developement of specialized swashplate part with reasonable ball bearing

- Developement of more compact, vibration-secured electric plugs and cables with adjustable lenght connecting electric parts. Current standard LEGO Technic/Mindstorms plugs and cables are too big, too heavy, too rigid and vibration-unsecured, making them useless for helicopters and even for speedy robots.

- Adptation of light servos in LEGO Technic environment. This is the costy part, but some coaxial rotor model helicopter designs do not need any servos.

- Developement of shock resistant piezo-gyroscope units: reasonable control of an RC model helicopoter requires 1-3 gyros (yaw trim at coaxial main rotor, pitch/roll/yaw trim at single main rotor). Current cheap gyros „go mad” after some hard crashes, which naturally occour frequently. Re-calibration of gyros with suitable software after crash may help.

- Developement of a flight computer, which communicates over wi-fi with flight control software on iPod or laptop. This way the costy, clumsy, battery-eating conventional RC-controller can be spared, and there is a possibility for two-way communication, transimitting on-board camera picture stream also. Ideally, flight computer should be programmable from PC/Mac GUI software. Using Fuzzy Systems enables performing difficult non-linear control tasks, created and continously refined on an intuitive graphic user interface, requiring only basic math knowledge (see FuzzyTech for example)

Edited by gjpauler

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bought a set tonight MISB 8068, paid $20.

the lady who sold it said his son doesn't like it...

DSC_0874.jpg

here's the only flaw...his son punctured the box, but seals are intact :laugh:

DSC_0876.jpg

Edited by francisalmario

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