[REVIEW] 9396 The Big Helicopter

[freakwave]

Thank you very much for the wonderful and very detailed review, Frekwave!

This set has been on my buying list since the first pics were released.

I actually wanted to stop buying Technic sets, because of my disability to create something different from it, but I'm a emergency physician, so this is THE set for me to call my own.

Do you have a photo without the stickers applied?

And do you see a way to add the rechargable battery box instead of the bulkier curved one whilst adding PF to the model?

I guess you have to change your nick into "helidoc" after you got it

I do not have a picture without stickers, I put them on straight through the build, some photoshop needs to be done...

The space on the bottom is 5 studs wide, so the rechargeable will fit in for sure, to make it attach properly a bit of adaptation is necessary. There is really plenty of space inside to mount additional motors and stuff.

@JunkstyleGio: Enjoy the build!

[allanp]

The RC buggy motor makes it awesome, tho probably not so child friendly

[TimH]

Great detailed review and video.

[toycardriver]

Great review! I just love the picture with the two helicopters, it brings back memories. I had that kit all those years ago, but lost it in my dark ages.

[Foggy]

Big compliments for your review.

I'm SURPRISED noone made a comparison between the 8856 and the 9396.

This is the real battle 'cause are both rescue copters!

So please give me some measures of the new one compared to the 8856 ones:

LENGHT 50cm (about 20in)

WIDTH 15cm (about 6in) without main rotor, just frame

HEIGHT 19cm (about 7.5in) with wheels down

ROTOR DIAMETER 37.5cm (about 15in)

I really like the old 8856 (I have 2 of them 'cause I like even the B model) and the flex system and I'm gonna buy soon even the 9396 BUT I thought lego would add even the tail rotor control to make the model as close as possible to real copters and this disappointed me

I even like the 8856 all red color and think the new one would be great in all yellow as the SAR copters usually are..

Hope to hear comments

Ciao

Edited July 13, 2012 by Foggy

[Theo van Vroenhoven]

Looks like a really nice build!

Apart from the rotor blades and the new axles most pieces are very common.

Does anybody know where and when we can buy the new pieces?

[JunkstyleGio]

Try Lego Direct in a few weeks...

[Crazydance]

Somehow the model seems slightly off compared to the sleek front of the 8068 chopper above.

Can you compare the model to this one? Helicopters that lego makes are cool most of the time.

This function-packed version is no difference.

Let's say we can choose between the 4x4 crawler and the chopper... First-world problems I tell you!

[DLuders]

Here are the first two of four YouTube videos posted by Conchas -- an "integral part of Alexander's [AVCampos'] review to the 2012 LEGO Technic set 9396, Helicopter. The full set review is now available at:

http://technicbricks.blogspot.pt/2012/07/tbs-techreview-16-9396-helicopter.html .

-- "Landing Gear and more

-- Rotor"

Edited July 14, 2012 by DLuders

[DLuders]

Here are the last two YouTube videos posted by Conchas in the TechnicBRICKS review of the Lego Technic 9396 Helicopter set. Recommend viewing them in HD (High Definition).

-- "Main Model

-- PF [Power Functions] Motorisation"

Edited July 14, 2012 by DLuders

[JunkstyleGio]

Awesome video's!

Usually Video's like these take away the fun of building; these only want me to start up as soon as possible!

But oh.... the time is going slow!

[freakwave]

In the meantime I built the B-Model as well and after reading AVCampos superb review I need to say that the tail-rotor/propeller in this model is not redundant, it is actually used to power the main rotors and when switched, to also raise the main landing gear.

I will add a few construction pictures and videos tomorrow (ran out of battery...).

The B-model's shape looks very sleak! The main landing gear retracts nearly all the way into the body. Motorizing is not foreseen by TLG and looks like a bit of challenge as some gearing needs to be changed to make the M-motor spin the blades. It takes some force to do it. Need to check all gears if they are properly installed.

It's colors are a bit off due the stickers on the panels.

But I need to say that I admire the set-designers for getting so much out of the primary model!

fW

[Phoxtane]

I will also say that the tail rotor on the B-model would not be redundant in real life; as far as I can tell, there's no way for the main rotors to actually tilt forward! Without that tail rotor, it'd only go up.

That's the Sikorsky X2, an experimental high-speed helicopter prototype. It's already set a new helicopter high-speed record of 259 miles an hour [418ish kilometers an hour, if you live across the pond]. Once it starts going fast enough, the main rotors slow down to the point where they keep it in the air, but aren't creating too much drag, and the tail rotor takes over.

[Blakbird]

I will also say that the tail rotor on the B-model would not be redundant in real life; as far as I can tell, there's no way for the main rotors to actually tilt forward! Without that tail rotor, it'd only go up.

There' no such thing as rotors that tilt forward. All helicopters use a cyclic to vary the pitch of the blades cyclically and produce forward thrust, and an intermeshing helicopter is no exception. So there really is no need to the tail "prop" in real life, although I understand its application on this model.

That's the Sikorsky X2, an experimental high-speed helicopter prototype. It's already set a new helicopter high-speed record of 259 miles an hour [418ish kilometers an hour, if you live across the pond]. Once it starts going fast enough, the main rotors slow down to the point where they keep it in the air, but aren't creating too much drag, and the tail rotor takes over.

The example you provided is fascinating! Not a true helicopter, but kind of a combination using a prop for thrust and a rotor for lift. Almost more like a gyro except the rotor is powered. Cool. The limiting factor for speed in a helicopter is that the combination of the rotor's tip speed and the helicopter's forward speed make the tip approach the speed of sound. This would destroy the rotor, so you can't go that fast. However, if you STOP the rotor and use it as a wing, then you have a much higher limit. The tip would still flutter if you went supersonic, but you don't have the rotating speed to contend with.

[EdmanZA]

The limiting factor for speed in a helicopter is that the combination of the rotor's tip speed and the helicopter's forward speed make the tip approach the speed of sound.

There's another limitation on the rotor blades on the other side of the hub too. If the forward speed becomes too high relative to the rotor speed, the effective airspeed over the trailing rotors approaches zero and they stall.

[cavegod]

also they are biased to either left or right depending on rotor direction so you have to compensate for that while flying and as said before with the cyclic control of the swash plate you get more lift on one side and thus without compensating you would roll over. Off topic a few hours ago a Chinook flew over lovely sound!!

[Phoxtane]

There' no such thing as rotors that tilt forward. All helicopters use a cyclic to vary the pitch of the blades cyclically and produce forward thrust, and an intermeshing helicopter is no exception. So there really is no need to the tail "prop" in real life, although I understand its application on this model.

Ah, yes, I remember that now.

I'm still going to maintain my opinion that the tail prop is necessary on the Sikorsky. According to the Wikipedia article on this aircraft, most of the power is transferred to the tail prop - which implies that the rotors are primarily used for upwards lift.

However, if you STOP the rotor and use it as a wing, then you have a much higher limit. The tip would still flutter if you went supersonic, but you don't have the rotating speed to contend with.

Intriguing. Unfortunately, I don't see how this would work without a massive rotor surface, which turns into drag at supersonic speeds. There's also the added weight to contend with... I think that at best your design would compromise the ability of the helicopter to fly.

By the way- I had it wrong. The tail rotor is actually a tail propellor!

[allanp]

My spidey sences were telling me that probably not all helicopers work the same. Here's a clip from one of my favorite shows. The interesting bit starts at about 1:18. The whole series is well worth a watch.

http://www.youtube.com/watch?v=hGZb1wTWNec&feature=relmfu

Larger heli's are basically the same in pricipal with the teeter bearing becoming less common the bigger the heli gets. A seaking resue helicopter works like this:

Edited July 17, 2012 by allanp

[freakwave]

so, got some delay in the B-model pictures but here they are!

A few compressed shots during the construction to show some of the mechanics.

Landing Gear:

Compared to the main model everything here is done with gears and axles, no linkages used to connect functions.

The main landing gear really folds very well!

9396_B_01 by 1wave, on Flickr

Main Rotor Pitch

Next up the mechanism to adjust the pitch on the main rotor. It is constructed much simpler than the A-model. The top two pictures show how the two "Axle 4L with Stop" are moving the red 3L Liftarm, the bottom two are the corresponding images with the linkages to the blade control already attached.

And this is in fact the small disadvantage here compare to the A-model. The B-Models pitch relies on gravity to move the rotor. Moving them up (horizontal position) is no issue as it is being pushed. Going down is working well without load, meaning without rotating blades. Once they reach a certain speed the centrifugal force wins over gravity and they do not come down. They stay in the "down" position nevertehless even if the rotor moves at high speed, but once horizontal, that's it... You need to stop it to let them move again.

9396_B_02 by 1wave, on Flickr

Leftovers:

Those are the leftover parts when you are finished with the B-Model:

9396_B_03 by 1wave, on Flickr

Functions:

As mentioned before, all functions are driven by the tail-rotor. This is convenient and gives ample control. The transmission is well chosen to retract the landing gear swiftly. Also the rotation of the main rotors is done in the same way. Switched by a driving ring, the force is directed to the rotor. The main-rotor also features the safety latch to have the rotor spinning freely when it is not driven anymore. This ratched mechanism is built a bit stronger, than the A-Model.

What's noticeable is that much more force required to spin the rotor. This is due to a transmission from the 24T Bevel Gear to a 12T Bevel gear. I guess the reason why they have designed it like this is to achieve a proper speed for the landing gear retraction.

On the other hand you cannot simply put a motor there, the torque required is too much and it is screaming...

To put a motor in line with the axle of the tail-rotor and make it move everything I swapped the 12T and the 24T this makes it much easier to drive! Video is coming! ... and yes, one of the things to consider with tilted rotors, the blades do hurt if they hit you (when driven with an RC-Motor) as their rotation plane is not spotted easily when spinning at....speed!

Finally a few eye-candy shots:

9396_B_07 by 1wave, on Flickr

The side view reveals the concession you have to make with the applied stickers. I would love to see this one in a black / dark bluish grey color scheme! I think it would look great! ...more evil :-)

9396_B_05 by 1wave, on Flickr

9396_B_06 by 1wave, on Flickr

enjoy!

[paul_delahaye]

I've just finished building the 9396 helicopter and it's big! no doubt about that, I think it was a great build, with the only mistake I made being missing a 16 tooth cog on step 75, which I only realised on completion and rotated the knob and nothing happened!

I have a couple of observations:

1, I just don't understand why Lego did not include the Small PF motor and battery box? the price point of this set was in line with last years flat bed truck, and more expensive that the hauler and skip truck from previous years, both of which included Power Functions?

2, I think they missed a trick not including a second Light Bley Panel which could have been used to fill the void where the battery box should go and this would create a floor inside the helicopter, the instructions even tell you to put light grey pins in ready for the battery box/floor panel.

The colour scheme is great, and the soft tips on the rotar is a nice touch, shame they did not put the soft edges on the tail rotars as well to match.

Just in case anyone is interested in the rotors from Lego direct, the part numbers for the lego rotor blades are:

Small Tail Rotars: 4651820

Large Main Rotars: 4651822

Paul

[Paul202]

This would be amazing, if only the panels came in black. :(

[freakwave]

Well it took me (or YT, but I guess it is more myself) some time to have the movie of the B-Model uploaded. iMovie worked so well uploading the first one, the second one took ages to upload and to be visible in the search results...

Enough moaning, here it is! Again the RC-motor rocks!

Edited August 2, 2012 by freakwave

[chorlton]

Well it took me (or YT, but I guess it is more myself) some time to have the movie of the B-Model uploaded. iMovie worked so well uploading the first one, the second one took ages to upload and to be visible in the search results...

Enough moaning, here it is! Again the RC-motor rocks!

Stick your fingers in the way while rotating. I dare you

[freakwave]

Stick your fingers in the way while rotating. I dare you

I actually did, accidentally... The 'scene' is cut from the clip, though, but the rubber tips are worth it! The problem with the tilted rotors is that it's harded to estimate where they are when rotating with, well, speed!

[JunkstyleGio]

Got the helicopter yesterday. Couldn't stop building.

Here is a photo with a size comparison with models 852 and 8068(b)

This was totally worth the wait.

Edit:

Added a PF-switch. I really don't like to work the switch on the batterybox.

Edited August 4, 2012 by JunkstyleGio