Realistic Helicopter Rotor Head Swashplate (Cyclic & Collective)

[Nachapon Lego]

WIP... New version at post #5.

2 YouTube Lego helicopter realistic roter head swashplate LDD cyclic & collective sim 4 by Nachapon S., on Flickr

YouTube Lego helicopter realistic roter head swashplate LDD cyclic & collective sim by Nachapon S., on Flickr

YouTube Lego helicopter realistic roter head swashplate LDD cyclic & collective sim official 9396 lxf by P4trickvH by Nachapon S., on Flickr

Edited December 30, 2013 by bbqqq

[Jeroen Ottens]

It's looking good so far, however you have to make sure that the swashplate and the rotorhead keep the same rotation. Otherwise your 6L linkages will wind themselves up.

[mahjqa]

The rotor blades will fall off.

[jantjeuh]

The rotor blades will fall off.

I think so as well. That axle connection is really a weak link.

[Nachapon Lego]

It's looking good so far, however you have to make sure that the swashplate and the rotorhead keep the same rotation. Otherwise your 6L linkages will wind themselves up.

The black cross in new design below will help the rotorhead to rotate together with upper part of the swash palte easier.

The rotor blades will fall off.

I think so as well. That axle connection is really a weak link.

Yes, old design have to cheat by string or drill small hole to prevent blades fall off.

Here are some better alternate new design.

YouTube Lego helicopter realistic roter head swashplate LDD cyclic & collective sim 2 by Nachapon S., on Flickr

YouTube Lego helicopter realistic roter head swashplate LDD cyclic & collective sim 3 by Nachapon S., on Flickr

Edited December 29, 2013 by bbqqq

[Lakop]

I've never ever built rotors but something like this will always need to be strong. Strengthen those rotors and you are well on your way. I would have to build and test your design to see how well it works.

H

[Hrafn]

Yes, old design have to cheat by string or drill small hole to prevent blades fall off.

Here are some better alternate new design.

The left-hand design seems somewhat more secure to me, since the pin on has a very strong clutch power in a hole. Still, at high enough speed you could have rotor blades flying out. I certainly wouldn't want to stand next to it!

That said, this is very cool.

[Nachapon Lego]

I've never ever built rotors but something like this will always need to be strong. Strengthen those rotors and you are well on your way. I would have to build and test your design to see how well it works.

H

Looking forward to see your result. I have built one with real brick, but a bit different design cause I don't have all the parts. Still need to design structure to hold and tilt bottom of the swashplate.

The left-hand design seems somewhat more secure to me, since the pin on has a very strong clutch power in a hole. Still, at high enough speed you could have rotor blades flying out. I certainly wouldn't want to stand next to it!

That said, this is very cool.

Maybe need to oil the turn table if rotate very fast. Insert a stick into the pin to prevent it from compress may help.

This video show different angle of each blade while cyclic.

Edited December 29, 2013 by bbqqq

[DrJB]

While there are some valid points above (feedback from others), I must commend the OP for such design. Then again, my primary goal/expectation with Lego, is to reproduce functionality/kinematics ... not necessarily strength. I think the OP has 'proved' that a fully functional swash plate (with both cyclic and collective) is certainly doable with the current assortment of Lego parts ... Good Job!

Edited December 29, 2013 by DrJB

[Lakop]

bbqqq,

I won't be attempting to build your idea as I'm currently working on something else at the moment. But I would like to see a working version.

H

While there are some valid points above (feedback from others), I must commend the OP for such design. Then again, my primary goal/expectation with Lego, is to reproduce functionality/kinematics ... Not necessarily strength. I think the OP has 'proved' that a fully functional swash plate (with both cyclic and collective) is certainly doable with the current assortment of Lego parts ... Good Job!

DrJB,

I, and i'm sure the other's, agree with you. A good design (though I know nothing about rotors) and well presented.

H

[Hrafn]

While there are some valid points above (feedback from others), I must commend the OP for such design. Then again, my primary goal/expectation with Lego, is to reproduce functionality/kinematics ... Not necessarily strength. I think the OP has 'proved' that a fully functional swash plate (with both cyclic and collective) is certainly doable with the current assortment of Lego parts ... Good Job!

Well said. DrJB's design is ingenious and very well presented. The animations are particularly helpful in conveying how it works.

[AndyC]

I'm not sure you could actually physically construct that left design, surely there isn't enough flex in that part to pin the rotors in like that using half pins? And if there is, surely they wouldn't stay in long?

[dr_spock]

Interesting idea. Have you had a chance to build a physical working model of it?

[DrJB]

I just realized an 'impossible' build on post #5 ... the 1.5 pins holding the blades cannot be mounted inside part 53533. Still, that can be remedied easily with other parts.

[Moz]

DrJB: Yes, but you could use 3 long pins with friction in an "illegal" way and it would work. TLG designed wouldn't be allowed that, but you can. And 3L pins are cheap enough that even if you do trash them after they've been like that for a few weeks it's no great loss. The extra bit sticking out could be used to hold something decorative :)

Or just 3L axles with half bushes each side to hold them in place.

[Nachapon Lego]

Thank you everyone for nice comments and suggestions.

Here are alternate blade pin. Use 2L axle with a cut-off non-lego rubber band.

Each blade can be mount with one pin only. just like most RC heli. Blades will auto expand when spin at high speed.

I wonder if with help of seesaw structure to balance the heli to almost zero in weight. Is it possible to wire remote lego heli to fly like real heli with real lift fore by roter spin?

2 YouTube Lego helicopter realistic roter head swashplate LDD cyclic & collective sim 6 by Nachapon S., on Flickr

2 YouTube Lego helicopter realistic roter head swashplate LDD cyclic & collective sim 5 by Nachapon S., on Flickr

Edited December 30, 2013 by bbqqq

[DrJB]

DrJB: Yes, but you could use 3 long pins with friction in an "illegal" way and it would work. TLG designed wouldn't be allowed that, but you can. And 3L pins are cheap enough that even if you do trash them after they've been like that for a few weeks it's no great loss. The extra bit sticking out could be used to hold something decorative :)

Or just 3L axles with half bushes each side to hold them in place.

Precisely, that is why I said ... 'but that can be easily remedied' ... I'd prefer 3L with stops and 2× 1/2 bushings , though it all depends on the parts assortment one has on hand.

On a different note, I tried to 'reproduce' the LDD file, and it's not trivial as the OP has a lot of experience with LDD (more than I'll ever attain).

Also, post #16 shows a 2L axle with stop .. is this a new part or another trick by the LDD Masters?

Edited December 30, 2013 by DrJB

[LEGO Train 12 Volts]

Very nice mechanism ...too complex for me!

[Technyk32231]

I just realized an 'impossible' build on post #5 ... the 1.5 pins holding the blades cannot be mounted inside part 53533. Still, that can be remedied easily with other parts.

Yes they can. It just takes a little force.

[Zerobricks]

There is another issue, the connector which holds the baldes via frivtion pin with axle can simple turn arround instead of totating the blades. You need to fix it.

[Lakop]

This is an interesting topic. With the rotors folded back the helicopter can be easily transported on an open trailer or inside a container truck.

H

[DrJB]

This is an interesting topic. With the rotors folded back the helicopter can be easily transported on an open trailer or inside a container truck.

H

True, though that option was already available on the original lego set. I keep mine with two opposing blades folded as the display shelf is not deep enough....

[Nachapon Lego]

Thank you everyone for nice comments and suggestions.

There is another issue, the connector which holds the baldes via frivtion pin with axle can simple turn arround instead of totating the blades. You need to fix it.

Agree, noticed that problem in 2nd YouTube video. Design below fix it but not look that good.

Cyclic Animation:

[Nachapon Lego]

Precisely, that is why I said ... 'but that can be easily remedied' ... I'd prefer 3L with stops and 2× 1/2 bushings , though it all depends on the parts assortment one has on hand.

On a different note, I tried to 'reproduce' the LDD file, and it's not trivial as the OP has a lot of experience with LDD (more than I'll ever attain).

Also, post #16 shows a 2L axle with stop .. is this a new part or another trick by the LDD Masters?

Regarding to the 2L axle with stop, Yes, it is possible to make some LDD custom brick without hack any software. Sample below.

http://www.eurobricks.com/forum/index.php?showtopic=62039&st=175#entry1742003

Update: Use four "connector peg with knob" (part #4274)(illegal) to mount each blade as YouTube below.

For real brick, just cut the 4L axle with stop. Sample below.

I found a new way to use group function that turn LDD LXF file into easy to use digital building instruction.

Authors can manual fully control steps and building order. No more confuse, no more long time waiting for big LDD file to auto generate LDD BI.

Group & sub-group bricks by building order -> hide all -> hide each group icon then undo(ctrl+Z)to make bricks show up in building order.

For simple way. Just select groups icon in order to make LDD highlight each brick step by step.

Edited December 31, 2013 by bbqqq

[steph77]

Hi ,

I am very impressed with your work , especially by your mastery of drawing by computer. Great work.

However, to have built myself several functional helicopters, I see two major problems in your installation .

The first is the binding of the mat of the rotor with the top part of the swashplate .

You should create a physical and articulated connection , a mechanical training compass. It is imperative to create this piece because without it the rotation will generate a lot of vibration. Note that fixing the compass must absolutely be made to the plane of the swashplate ( see below)

The second problem, which is not the least of which is that it is absolutely neccessary that your swashplate is a perfect plane between the ball joint of the low bet and the ball joints of the upper part of the swashplate . Again, your installation will generate a lot of vibration. In a general way you also must minimize the weight , the mass, of the rotating parts to minimize the problems of vibrations.

In short, everything is history of equilibrium mass and homokinetism in the building.

And, I know, it's much easier said than done!

Otherwise, have you looked at the command system that controls this all?

This part of the design is also difficult. from my experience, be careful at the outset points:

First set the point of attachment of the rotor mast highest as possible. indeed lego axes are flexible and do not help to solve vibration problems.

secondly, ensures a secure and perfecty guided mechanism (vertical and tilting) for your swashplate. this for the same reasons ...

Finally, avoids toothed parts in your kinematic chain commands. they generate small 'play' in the mechanism that are really harmful to the proper functioning and stability of the whole. Therefore only uses systems linkage secured and guided.

Well, good luck to you, do not hesitate to build a real model, you will quickly realize what I mean with my stories of vibration ...

@+

!

Edited January 1, 2014 by Blakbird
Fixed font.