[MOC] Large helicopter

[Jeroen Ottens]

Hi,

I’d like to present my latest model. This time it is large motorized helicopter. It has a rotorspan (if that is a word) of one meter and also the body is one meter long. It has all the controls that you expect in a helicopter:
– Collective pitch control
– Cycling pitch control
– Anti-torque tail rotor control

Side view with the doors closed and landinggear retracted

 

The controls can be operated manually either from the cockpit (cyclic sticks, collective levers and anti-torque pedals) or through small HoG knobs on the rear underside of the main fuselage. It is also possible to add four servo motors to the model to control all these functions remotely via IR.

Furthermore this helicopter is equipped with a retractable rope at the side, a fully articulated camera/searchlight under the nose and a retractable landinggear. All these functions are motorized as well and remotely controlled via IR.

The camera/searchlight in the front can rotate 180 degrees side-to-side and 360 degrees front-to-back

Finally the doors in the front can open as well as the sidedoors that can slide backwards to give access to the spacious interior. When closed these doors sit completely flush with the fuselage.

The model is so large that it is difficult to get proper photos of it, that’s why I chose in this case to only show renders.

Comments, feedback and questions are appreciated as always. Instructions are for sale on my website and the partslist is available on Rebrickable.

Topview that shows the massive one meter rotor-span

[JintaiZ]

Fantastic build!

[Gray Gear]

Looks very nice, I like the helicopters that have a nose like this. Its giving the machine more character.

Do you only have the digital model or/will there be a real brickbuilt model?

Overall the body look prety clean and simple. But I think there is some room for improvement in the fron area, that huge gap between the curved side panels and the top ones just isn't nice to look at.

Thx for sharing!

[MinusAndy]

Fabulous! 
I have a constant internal battle to not go down the rabbit hole of building a large scale alouette2. Seeing this makes me want to build one even more. 
The blade droop when stood still will look really accurate too if you can build this physically

[steph77]

Looks good!

I have some questions, sir

- Do you have built it IRL? I guess yes at reading your post.

- How does the blades bend under their wheight?

- I've tryed for long to use the large turntable to build the swashplate but i faced too much problems of stability, vibrations and overal reliability, how does your system work?

- A selected view of the commands would be appreciated (only the upper part and essentially the mixing unit). Where do you mix collective and cyclic? from my experience the nearest you do it to the control stick, the best it works. It is obviously not the only way to acheived that. On your pictures i Believe you've done it directly on the rotor hub (like the real UH-1) true?

And if you had a video...

S.

 

Edited November 13, 2020 by steph77
typo

[Jeroen Ottens]

16 hours ago, Gray Gear said:

Looks very nice, I like the helicopters that have a nose like this. Its giving the machine more character.

Do you only have the digital model or/will there be a real brickbuilt model?

Overall the body look prety clean and simple. But I think there is some room for improvement in the fron area, that huge gap between the curved side panels and the top ones just isn't nice to look at.

Thx for sharing!

Thanks. That gap has been bothering me as well, but I couldn't find a satisfactory solution for it so I decided to keep it. IRL it is less bothersome than on a render though.

15 hours ago, MinusAndy said:

Fabulous! 
I have a constant internal battle to not go down the rabbit hole of building a large scale alouette2. Seeing this makes me want to build one even more. 
The blade droop when stood still will look really accurate too if you can build this physically

Indeed, the blades swoop down about 8 cm. When rotating they come up a little bit though.

15 hours ago, steph77 said:

Looks good!

I have some questions, sir

- Do you have built it IRL? I guess yes at reading your post.

- How does the blades bend under their wheight?

- I've tryed for long to use the large turntable to build the swashplate but i faced too much problems of stability, vibrations and overal reliability, how does your system work?

- A selected view of the commands would be appreciated (only the upper part and essentially the mixing unit). Where do you mix collective and cyclic? from my experience the nearest you do it to the control stick, the best it works. It is obviously not the only way to acheived that. On your pictures i Believe you've done it directly on the rotor hub (like the real UH-1) true?

And if you had a video...

S.

 

Yes I have it standing in my LEGO room. I've tried to photograph it, but the photos really aren't great. The model is so big that it is difficult to get it properly lighted and have a non-cluttered background.

The blades stay straight, but they hang at an angle. They are surprisingly sturdy.

The problem of using the large turntable as a swashplate is the fact that it doesn't have a sliding ball-joint connection to the central shaft. So I made a linkage system that has that ability of transfering the rotation of the shaft to the turntable, while at the same time giving it the ability to tilt in all directions and move up and down:

When building the helicopter I wanted to keep the compartment behind the cockpit completely empty. So all the controls had to go either under the floor, or in the wall behind the cockpit or in the ceiling. So the mixing unit is in and below the floor (it is very similar to the mixing unit you used in your AW169), three beams go up in the wall behind the cockpit and then three levers connect these beams to the pushrods on the swashplate. Below the floor the controls are also routed to the back where they can be operated through 4 HoG's at the underside. This is also where the servomotors can connect to the controls.

Videos are even a bigger challenge for me than photos. They take so much time to make that I rather spend on building. So if anyone is interested in making a video send me a PM and you can get the instructions for free.

[ifilin]

Thank You very much, Jeroen, for this incredible helicopter.

As I understood, it is possible to build it without Servo motors using your instruction?

My son likes to build planes and helicopters, but we've got only 3 servos.

P.S. Your Tomсat in our to-do list. :)

Edited November 14, 2020 by ifilin

[dhc6twinotter]

It's always great seeing your various builds, Jeroen.  Top quality stuff!  Helicopter MOCs are always great to see!  I like how you've built the swash plate.  How is the tail rotor built?

[Jeroen Ottens]

10 hours ago, ifilin said:

Thank You very much, Jeroen, for this incredible helicopter.

As I understood, it is possible to build it without Servo motors using your instruction?

My son likes to build planes and helicopters, but we've got only 3 servos.

P.S. Your Tomсat in our to-do list. :)

Thanks. Yes it is possible to build this without the servo-motors. You can then also leave out two IR receivers. If you also give up on the led-lighting you can leave out the extension cable as well. Enjoy the build! And get some serious shelf space

7 hours ago, dhc6twinotter said:

It's always great seeing your various builds, Jeroen.  Top quality stuff!  Helicopter MOCs are always great to see!  I like how you've built the swash plate.  How is the tail rotor built?

Here is picture of the tail rotor. Again @steph77's Augusta Westland 169 model from some time back gave the idea of using the wheel hub.

@steph77: Here is a view of the inside:

And thanks for all the positive replies

[howitzer]

That wheel hub in tail rotor is really ingenious!

And the view inside makes me feel like I'm looking at a real helicopter, not just a model. All those shafts and motors and stuff going to various places, while still having space for an actual cabin and cockpit.

[jorgeopesi]

I forgot to comment that awesome helicopter,  this machine teachs a lot of interesting tecniques.

[MinusAndy]

I’d love to see some bad photos and videos of the real thing. I’m something of an expert on bad photography so if you need advice on cluttering up your background with other Mocs, adding blur and poorly lighting it, I’m your man.

On a serious note, I’d be really interested to see how you’ve dealt with backlash from the joysticks etc.

[SNIPE]

Amazing set as usual. this should be a technic 2h 2021 set! those new frames really are a godsend.

Will there be a video showing it off ? (I assume there will but idk).

I'm thinking about buying this set next year for sure!.

Edited November 15, 2020 by SNIPE

[captainmib]

Amazing model.

The interior shot shows a lot better how massive this thing is.

I was wondering how you mix the different inputs.

(I'm building something with flapperons myself, and I'm still not done figuring it out. Maybe you have some tips)

 

And maybe I'm seeing things, but what are the wheels for? Landing gear?

[steph77]

9 hours ago, Jeroen Ottens said:

 

@steph77: Here is a view of the inside:

 

Typically what i was expecting!

Ahh those helicopter Mocs are always a little bit of challenging our brains!

Pleased to ear that my work may have inspired you !

Maybe you could replace this 3blades rotor by a 2 blades one (likely more credible as the main rotor has 4 blades) Go to my general topic and look at the 'liberator'. I used the mini turntable and it work just fine.

With a little more headache , it may be possible to convert it in a 4 blades one. I'll have a look at it and let you know the results. This could make this one even better.

 

...By the way, i build your swashplate today, and things goes wrong for me.

Except for the collective movement that goes right, impossible to inclinate the swashplate, it locks itself due to the geometry of the pushrod system...

I guess something was wrong in my built, or, in yours, the maximum angle possible for the swashplate is very tiny...

 

I'll have a very close look at the picture below to see how you've routed all the commands.

 

Thanks for sharing this!

 

S.

[Jeroen Ottens]

Thanks all. Some answers to the questions:

I am not sure about photos TBH. I've tried to photograph this a couple of times, but it is really hard to get a proper photo of such a large model. I do feel that I need to reach a certain quality of photography before I want to post it.

Videos are even a bigger thing for me. It takes me about one hour of editing per minute of video. At least to reach that minimum level of quality that I set for myself. I have so many projects I'd rather work on, that I push this photo/video work away. If anyone is interested in making photos/videos of models I make you can PM me and we can see if we can work something out.

@captainmib: Yes this model has a retractable landinggear.

@steph77: The swashplate has a +/-1 stud tilt capacity, which I considered enough for the tilt of the rotors. Can you reach that? If not, can you send me a photo of your setup? MOD-ing the design to have a 4-blade rotor in the back is what LEGO is about 

[MinusAndy]

On 11/15/2020 at 2:44 PM, captainmib said:

Amazing model.

The interior shot shows a lot better how massive this thing is.

I was wondering how you mix the different inputs.

(I'm building something with flapperons myself, and I'm still not done figuring it out. Maybe you have some tips)

 

I’m also currently building flaperons and struggling with backlash. We should talk. 

[Jeroen Ottens]

1 hour ago, MinusAndy said:

I’m also currently building flaperons and struggling with backlash. We should talk. 

I use a couple of tricks:

1) I minimize the number of pivot-points in the mechanism. So I try to make the path from the controls to the controlsurfaces as straight as possible
2) I use ball-joint links when possible. I have the idea these have less slack
3) For large distances I try to use moving beams instead of rotating axles. The rotational stiffness of axles is quite poor and gives a lot of elastic position loss
4) I start with larger exitations and minimize the excitation at the control surface. If you start with a +/-1 stud movement and you need only +/-0.5 stud at the controlsurface you have some room to deal with the slack
5) I usually add a separate HoG somewhere in the middle of the system. This way you can use this to control both the joystick (that typically has only a limited range of movement) and the controlsurface. Effectively this reduces the slack by a factor 2 when using the HoG for operating the controlsurfaces compared to using the joystick for it

[MinusAndy]

The hog is the route I’m going down at the minute. 
I like the beams instead of axles approach too! Genius idea.

[dhc6twinotter]

19 hours ago, MinusAndy said:

The hog is the route I’m going down at the minute. 
I like the beams instead of axles approach too! Genius idea.

Pushrods work well too, especially for mitigating slack and/or backlash.   I guess that's the same idea as beams too.  

[HydroWorld - HydroSchool]

Any status on a video for this model? Has anyone volunteered yet? I would really like to see this model's functions in action!

For those who are wondering, I would make the video if I could, but I don't have enough parts to build this model.

Edited March 15, 2021 by HydroWorld - HydroSchool