[TC15] AH-77S - HUNTER

[1gor]

Sorry to be late on party, but I like black even better 

[Ivan_M]

DBG with black is indeed very nice and possible to build:

1546803591m_Copy

There are also #3 and #4 panels in DBG already so the only panels missing in DBG are 1,2 and 5,6

 

[steph77]

looks good.

But for some reasons i think it's better to keep it white.

I think that more people could have the parts in the good color this way, as not everyone own the Mack set.

EDIT: BTW, where did you find those black shock absorbers?

Edited January 14, 2019 by steph77

[Ivan_M]

Sooo, it was quicker than expected, here it is:

https://drive.google.com/file/d/1Ttu5sF8GB6yf-VWw2HMFu_awwUXtrDNf/view?usp=sharing

An entry on rebrickable will be available soon. I have made several minor changes, mostly to save some part, use more common one or to make some assembly easier to build or to fit. Have fun

edit: https://rebrickable.com/mocs/MOC-21317/Ivan_M/ah-77-hunter-helicopter/#comments

Edited January 18, 2019 by Ivan_M
Rebrickable link

[steph77]

I just have to thank @Ivan_Mfor the excellent job on these instructions. I pass a couple of hours to check these instructions. I can tell you all that this guy made a way deeper work than it could seem at first look. I really hope for all those who will build it you will enjoy it as much as I does when designing it. Again thanks at Ivan.

[HorcikDesigns]

Thank you, @steph77 and @Ivan_M for sharing the instructions, I look forward to build this model. (at least basic frame of it - with all functions)

[fosamax]

On 1/14/2019 at 6:26 PM, steph77 said:

looks good.

But for some reasons i think it's better to keep it white.

I think that more people could have the parts in the good color this way, as not everyone own the Mack set.

EDIT: BTW, where did you find those black shock absorbers?

You will find the black shocks on page 3 of that thread https://www.eurobricks.com/forum/index.php?/forums/topic/167699-cada-battery-with-4-motor-outputs-and-remote-control/&page=3 so it's not a lego part.

[steph77]

So these shock absorber will remain in yellow. Thanks for the info.

[HorcikDesigns]

I could not resist building this awesome MOC. I changed some details, in order not to wait for the parts, and to look similar to 8444.
Hope you like it, and also you won't mind sharing it here. Thank you @steph77 and @Ivan_M for allowing us to enjoy this model too.
Good luck in the contest!

I inverted the gun-joystick connection - inverted the rotation (but it is not so strong, compared to the original)
I hope to continue in the modifications in the future.

Edited January 21, 2019 by HorcikDesigns

[steph77]

1 hour ago, HorcikDesigns said:

I could not resist building this awesome MOC. I changed some details, in order not to wait for the parts, and to look similar to 8444.
Hope you like it, and also you won't mind sharing it here. Thank you @steph77 and @Ivan_M for allowing us to enjoy this model too.
Good luck in the contest!

I inverted the gun-joystick connection - inverted the rotation (but it is not so strong, compared to the original)
I hope to continue in the modifications in the future.

 

So there is one more hunter in the EB sky. I am just honored you build it so no problem to post here. If it goes this way this topic is going to turn into a mod en and improvement one  

[steph77]

some try at pop up visual to prepare the final review:

@Jim when do you think unlocking the entry topic?

I will be out of land for a job travel during the finishline  of this contest and i would like posting it next Week...

[Rudivdk]

I just couldn't resist...

It's a fantastic build, interesting, sturdy, smooth functions: very well done!

[steph77]

I didn't understand, based on picture, that your model was so big! it looks pretty cool to me

the hunter is already a big model...

BTW, thanks for your kind comments  it's well the first time, I think, that a guy post the picture of another contestant in the same contest!

I like this blue color also. So now we have a white one, green (on rebrickable) , blue. Still missing black ops version. Who will be the next?

[Rudivdk]

I was actually surprised about the size of the Hunter, I think they end up in similar scale. They are same length, only P38 is wider of course.

After completing I just had to take a pic of them together...

Hope you don't mind seeing my build pop up in your topic during the contest though. Just say the word and I will remove it...

[steph77]

22 minutes ago, Rudivdk said:

Hope you don't mind seeing my build pop up in your topic during the contest though. Just say the word and I will remove it...

Contest are for fun first… No problem with that

[Rudivdk]

[steph77]

@Jim Entry topic is still locked. i'll be out for work this week, if i cannot post my entry today it will be post next week, and maybe a little late.

Ok for you?

[Mechbuilds]

When i see cool builds like these, it makes me wish lego made RC helicopter motors so we could actually fly these things.. 

[nigel1975]

Another great design for the competition, been really interesting following the design evolution.

Nice side-by-side comparison with my other favorite entry :-)

[steph77]

AH-77 HUNTER : THE FINAL REVIEW

This is my final presentation for this contest.

General overview :

dimensions: 65(L) X 27(W) X 20(H)

Weight with standard batteries : 1.208 kg

Parts count: 1421

LDD file : http://www.moc-pages.com/moc.php/450322

PDF Instructions credits @Ivan_M : https://rebrickable.com/mocs/MOC-21317/Ivan_M/ah-77-hunter-helicopter/#bi

 

Functionalities embedded:

- Flight control:

     - collective main blades control by a lever,

     - cyclic main blade control by a joystick in the cockpit,

     - tail rotor pitch control by a lever

- Adjustable rear spoiler by a control gear

- Orientable IR pod and front gun by a joystick in the cockpit

- Motorized rotors and functional fake turbo-engines

- Opening elements like doors of the cockpit, engine compartment

- Functional suspensions on main landing gear

- Orientable rear landing gear wheel

In the following section i'll try to give the maximum of information specially on the conception POV

The technical design:

I do not based this MOC on any defined real machine. However the general conception is the mixing between some cobra and apache design

From my experience on building such project I quickly defined a basic design for this model. Building Lego helicopters mean you need to understand the constrains and reserve the neccecery spaces in your build to integrate the mechanics, especially the flight controls. By separate the flight control and gun control I dedicated the space for each functionalities. as the flight control need more space, I place them under the pilot seat, as this one is higher than gunner's one.

The other main aspect is the motorization integration. As Lego batteries box and engines are difficult to integrate in a helicopter design, I take the decision to use the BB as part of the design itself, it take place as a credible technical compartment of the aircraft. About the two medium motor I used, I choose this setup as I wanted a single two blades rotor. This meaned a slightly higher RPM setup to keep a good dynamic impression when rotor engaged.

About the flight control, my very first goal was, after quick  Mocup test, to demonstrate the real functionalities and have a visual impact of the flight control on the rotor head and blades.

The very important thing to understand here is that whatever the swashplale position it is the real aerodynamic effect of the blades that is shown. For this reason, the rotor head is fully articulated. This also mean I had to integrate the whole constrain of a real flight machine and particularly the gyroscopical effect. In a sense I think that the only missing thing for it to flight is some real power...

The last aspect I kept in mind from the very beginning of the build was to get the system vibration in acceptable limits. This had a real incidence on the joystic design, the choice of each single pin (with or without friction), the main mast design,...This was the really harder part.

Then and finally there was to integrate all these minded things in a cool model. The build was also concentrated on the clean design of each element and this in order to get a sturdy and well designed model

The design:

Based on a narrow frame and tandem pilot position, the overall shape had to give a powerfull and nasty aspect. It's a hunter after all...

I worked this model on one high table so I mainly looked at it from a 'ground POV' and here is the result:

From the back the overall shape is quiet good. Note the design work on the underside armouring. Directly inspired by the apache real model. In case of ground fireing the pilot has to expose the underside of the helicopter who is specially armored. The underpart is therefore wider than the cockpit.

The cockpit area integrate a scaled place for two pilots. with the joystic commands in right place. As the model is really thick I take the decision to simplify the integration of the tail rotor and the collective lever. They are located outside of the cockpit. I also didn't wanted to place any printed parts to simulate computers or flight commodos. I made the choice to keep in a 'pure technic' design

The gunner seat is also ergonomically thought and credible for a pilot to seat in. The correspondent joystick controls the tilting and rotation of the main front gun and pods.

I made use of professional stickers to enhance the exterior design

I do add a little lever that locks the collective lever, this one tended to vibrate with the blade rotation. it gives a free position, high and low lock:

these are the possibilities of the main gun and pod positions:

Moving to the side here is a still not shown view of the rotating fake engine of the hunter. The two engine are located on opposite side and connected to the main transmission.

I use of some little 1X5 panels to simulate some physical protections of the engines.

The engine bay is openable :

moving to the back of the aircraft we have the stabilization flap: this one is intended to eliminate the residual vibration generated by the flight at high speed and the thrust generated is adjustable according to the flight speed and exterior conditions. command by the lateral black gear.

Finally the rotors...

these pictures show you the maximum angle of the main blades: neutral position - maximum collective pitch (thinking that the cyclic pitch still need to be added and by consequence the rotor head design always need to take care of this aspect)

maximum cyclic pitch:

The tail rotor has, this time, positive and negative angles

And now some static view of the aero effect on main rotor: full pitch backwards - full pitch frontwards and the respective effect on main rotor inclination:

see the final part of the video to  complete this explanation. The left and right action on the control stick has the respective same effect.

It's difficult to explain how the controls goes, here is one underside view. Go to the instruction by following the link above for more. central rod controls the front back inclination of the swashplate, the exteriors ones controls the left/right movement. The collective stick makes both of the 3 rods go up and down.

the motorization integrate a clutch on each engine for safety, and for the same safety reason I place a link between the two blades:

top view:

Don't forget: there is one hunter in the EB sky:

Video

 

final words:

This was a great and fun build time! I am happy with the final results.

I would like to thank @Ivan_M for creating instructions of a great quality.

Thanks to those of you who already build it and give kind returns.

Edited February 12, 2019 by steph77
added video

[MangaNOID]

22 hours ago, steph77 said:



Superb build!

do the blades on the real one really tilt like that? Incredible! I’ve never seen like that before. I’m no guru of course though. 

[steph77]

2 hours ago, MangaNOID said:

Superb build!

do the blades on the real one really tilt like that? Incredible! I’ve never seen like that before. I’m no guru of course though. 

Thanks! About the blades: They does…

EDIT : some precisons.

In fact if you make the real rotor turn at the same rpm than the lego model, you will get the same result.

With higher power the Energy, by gyroscopical effect, is transfered to the aircraft's structure. the whole rotor, according to physical rules will keep a stable angle relatively to the aircraft itself,

explanations:

Hope this is clear...

Edited February 13, 2019 by steph77

[MangaNOID]

So in essence this all makes the AH-77S more manouverable... yeah I don’t understand but interesting nonetheless.

I’d like to build this thing to see what one of your helicopters is all about. Thank you for making instructions @Ivan_M I’ve got many parts missing from the list though but all in good time.

[steph77]

6 hours ago, MangaNOID said:

So in essence this all makes the AH-77S more manouverable... yeah I don’t understand but interesting nonetheless.

I’d like to build this thing to see what one of your helicopters is all about. Thank you for making instructions @Ivan_M I’ve got many parts missing from the list though but all in good time. 

The only vital parts are the swashplate elements.

If you do have them, it wouldn't be a major problem to build it :)

[MangaNOID]

thanks @steph77 I do have those laying around unused () I have had a look through the free (? ) building instructions and I think I can get most of the way through the Technic bits no problem actually but Im probably just missing a few half liftarms L shape and turbine elements so I'll give it a go in the next few weeks when there is time and see how far I get and add any to future bricklink orders as necessary.

 again.