Enough "lift" for helicopter flight

[TechnicJuan]

So TBS, you are telling all of us that if you took this plane to an open field with absolutely no string attached to it what so ever, and you turned on the propellers that it would actually lift off of the ground and into the air and be stable there?

If that is the case, then that is the video that you need to create and post for all to see.

[Sokratesz]

Let it go, it doesn't fly =p

[TBS]

@Juan

///Ok.......... Minute 2 shows it flying in circles with the above attached device that keeps it in place but you left out the liftoff part in that piece of unveiled video that would have proven your liftoff claim. ///

Here is a symbolic pic of the "device" you mean which is clearly to see.

http://www.stanleylondon.com/auscale1.jpg

Of course there must be a string, its also visible.

The balanced weight which the rotors have to move was maybe 10-15 gram in order

to lift or to land on the ground. So one side had to have balanceweight / magnets as heavy as the plane. Its that simple. What shall i tell else ?

///What about at the 1:20 mark when the engines cut out and it seems to float to the ground? When the engines began to cut off one would think that it should have fell like a rock.///

See above. ~10 gram on a string don´t drop like a stone.

Watch all the Videos of my pal itchy,

The rotors were steered with the big IR-control, you can accelarate them slowly, also turn down this way as well as instant via the red button. (this is what you mean by rotor instant off)

///There have been several other points made about how the liftoff looks "staged" the wings showing no signs of flex is another key that seems to go unexplained.///

Nothing is staged, considering Videos we´re to "dumb" and lazy to make any special FX at all.

The wings are full liftarms and sturdy. Nothing has to flex here. balanced weight is 10 gram.

@LasseD

///Can someone please ask those guys in German if they claim that this model lifts itself ///

Yes. again balanced weight is 10 gram.

///and would be able to do so without the string which clearly has to be used to lift it?///

Of course not. Lego is a good toy, but will and can never be the same as an aerodynamic fuel-driven RC model-plane. No one ever made that claim. These are 2 different shoes and should be clear at first sight.

@Juan

///So TBS, you are telling all of us that if you took this plane to an open field with absolutely no string attached to it what so ever, and you turned on the propellers that it would actually lift off of the ground and into the air and be stable there?///

No, i never did. LEGO Motors / XL-Motors, even 4, will never lift 2 bulky kilogram plastic in the air.

How did you get that idea from what i wrote ??

Some little gram work as you have seen, its about the balanceweight!

@SOK

///I'm not sure what you are trying to do, but it's not flying,///

Depends on the viewpoint. it lifts, lands, and flies forward by itself as long the rope lets it.

///so stop pretending.///

Never did, Its my pals vids... i post this just for explanation and understanding how it worked.

///The only thing it does is move itself through air while suspended on a wire.///

haha... thats great, brought into 2-3 words for youtube, how would you name

this method of moving then ?????????? flying maybe?

Did you ever believe this is a plane made of bulky lego-bricks which flies like the real ones ???

With an light sensitve LEGO-IR Control ??? This must be joke of you.

However its a Lego-device moving through the air controlled.

And for this its quite good, and was fun seeing it in real.

Hope you understood me.

Tom

[Lasse D]

OK. I get it now TBS. It is just a question of semantics.

The model does indeed fly in the way you describe (and define) because the setup makes sure the weight is low.

It is simply a different way of achieving the similar result of using a large helium balloon.

That said. It is a very nice plane and it seems to function quite nicely.

The original question is: Can you make a LEGO helicopter fly without any means of suspension/balloons to help out with the weight, and with current day LEGO, that answer must be: No.

[DLuders]

[bUMP]

Itchy4000 posted this

of a Lego Bell-Boeing V-22 Osprey FLYING under its own power. He wrote, "This video is for all the people they say it is fake and I am a liar. Here you can see how it works. It give no external touch, only a lever with a counterweight. Powered by 4 Lego XL motors and controlled by LEGO ® Power Functions IR Speed​Remote Control (8879)."

Edited December 24, 2011 by DLuders

[Zerobricks]

Still aint lifting off and flying under its own power, so yeah... Doesnt deserve the hype IMO.

[DLuders]

Yes, this V-22 Osprey is "flying" under the definition in this Wikipedia article about "Flight" -- "Flight is the process by which an object moves either through an atmosphere (especially the air) or beyond it (as in the case of spaceflight) by generating lift or propulsive thrust, or aerostatically using buoyancy, or by simple ballistic movement."

"Mechanical flight is the use of a machine to fly. These machines include aircraft such as airplanes, gliders, helicopters, autogyros, airships, balloons, ornithopters as well as spacecraft."

"Because the craft is heavier than air, it must use the force of lift to overcome its weight."

The non-Lego rotors are generating the lift. The inaminate string and wooden counterweight is not generating the lift.

For those "Lego Purists" out there, I wonder how much lift could be generated by the white 89509 "Propeller 1 Blade 14L with Two Pin Holes and Four Axles" parts that come in the 9688 Lego Renewable Energy Add-On Set, if they rotated at the same speed as the rotors in the video?

[timslegos]

What exactly does the counterweight do?

tim

[DLuders]

The counterweight provides a measure of CONTROL, and the rotating mobile arrangement allows the helicopter to "fly" in a circular pattern. We're not talking about fantastic, 100%-CONTROLLED FLIGHT here -- it flies just as well as this toy does if it were attached to the same mobile:

Whether it's rubberband power (in the balsa plane), or the Lego V-22 Osprey (with its onboard motors and battery boxes), energy is transfered to the rotating rotors to generate LIFT. They both "fly" in the strict definition of the word.

Edited December 24, 2011 by DLuders

[andythenorth]

What exactly does the counterweight do?

Effectively it reduces the mass of the plane.

[DLuders]

No, the wooden counterweight does not "Effectively it reduces the mass of the plane" -- the Osprey and the wooden counterweight are BALANCED and can stay in equilibrium for as long as the Osprey's batteries hold out.

Edited December 24, 2011 by DLuders

[TechnicJuan]

The counterweight provides a measure of CONTROL, and the rotating mobile arrangement allows the helicopter to "fly" in a circular pattern. We're not talking about fantastic, 100%-CONTROLLED FLIGHT here -- it flies just as well as this toy does if it were attached to the same mobile:

Whether it's rubberband power (in the balsa plane), or the Lego V-22 Osprey (with its onboard motors and battery boxes), energy is transfered to the rotating rotors to generate LIFT. They both "fly" in the strict definition of the word.

I am sorry, but this model in question is 100% not lifting it's own weight with it's own power in order to achieve flight. It is being assisted by the counterweight. this is the same thing as if it was being slightly assisted by pulling the string with your hand. There is no question that when it is being helped lfting off of the ground that it can fly in circles, but the liftoff of this is not realistic by any means. If you take away the non lego counterweight, this thing will sit on the ground and do nothing.

The balsa wood plane is an entirely different principle that what is being demonstrated in those videos that you linked due the nearly non existent weight. You can take a balsa wood rubberband plane and set it on the edge of a building and it will propel itself forward off of the building and fly while this Lego Plane would do nothing.

[DLuders]

Let's draw an analogy between the V-22 Osprey and this crane below, which can lift 1000 grams at 100 cm. It could lift more (up to 9 kg at 20 cm) if the boom angle and counterweights are just right. The relationship between the LOAD and the COUNTERWEIGHT is the "mechanical advantage". The crane is truly "lifting" all of that weight via its onboard motors.

The Osprey provides LIFT and is FLYING in the vertical-->horizontal direction under its own power. Sure, it uses the "mechanical advantage" of the counterweight but IT IS FLYING HORIZONTALLY via LIFT from its propeller blades. It is "flying" as much as that crane is "lifting".

[TechnicJuan]

David, I completely understand what you are saying and trying to explain, but this topic was about a vehicle made out of Lego lifting off under his own power. Yes this vehicle in question is lifting off the ground and flying in circles under it's own power, but it is being assisted which is defeating the purpose of what this topic was about.

It's basically like attaching a bunch of helium balloons to it that almost have it ready to lift off of the ground and then turning on the propellers and gaining lift.

[KEvron]

uh, a counter-weight does reduce the effective mass of an object.

KEvron

[5150 Lego]

David, I completely understand what you are saying and trying to explain, but this topic was about a vehicle made out of Lego lifting off under his own power. Yes this vehicle in question is lifting off the ground and flying in circles under it's own power, but it is being assisted which is defeating the purpose of what this topic was about.

It's basically like attaching a bunch of helium balloons to it that almost have it ready to lift off of the ground and then turning on the propellers and gaining lift.

Jaun is 100% correct. We understand that "technically" this is lifting up using the lift from the rotors as well as the power from the LEGO XL motors. But it is not lifting its own weight. That is the question at hand. Can a LEGo powered vehicle, effectively lift a Lego vehicle under its own power? This vehicle does not demonstrate this ability considering it has a counterweight. Remove the counterweight and this model will go no where.

[DLuders]

uh, a counter-weight does reduce the effective mass of an object.

In this Wikipedia article about "Mass", it says "Weight is the gravitational force acting on a given body, while mass is an intrinsic property of this body." "In everyday usage, mass is often referred to as weight, the units of which are often taken to be kilograms (for instance, a person may state that their weight is 75 kg). In scientific use, however, the term weight refers to a different, yet related, property of matter. Weight is the gravitational force acting on a given body...." The MASS of the V-22 Osprey does not change, but yes the "effective" WEIGHT of the helicopter is changed by the counterweight.

If one looks at ISOGAWAYoshihito's

of a Lego solar airplane, it is "flying" horizontally just like the V-22 Osprey according to the Wikipedia definition of "Flight" -- "Flight is the process by which an object moves either through an atmosphere (especially the air) or beyond it (as in the case of spaceflight) by generating lift or propulsive thrust, or aerostatically using buoyancy, or by simple ballistic movement." Yes, Lego models CAN FLY. The V-22 Osprey needs gravity-assist from the counterweight but it CAN FLY horizontally using the lift generated from the propellers to move it forward.

[KEvron]

propulsion is not flight. though it has a propellor, a torpedo in the water does not fly by the mechanical advantage of displacement.

i'm sorry, D, but i won't agree with you on this one.

KEvron

[andythenorth]

i'm sorry, D, but i won't agree with you on this one.

He's right about the physics though - I should have said weight not mass.

[KEvron]

I should have said weight not mass.

in his study of the two-body problem, newton refered to effective inertial mass as reduced mass, with regard to one body of mass affecting another:

m(reduced) = (m1 x m2)/(m1 + m2)

as for the issue of "is it flight or isn't it": by semantics, i suppose D is correct, but i'd just as soon continue to refer to flight, as we commonly understand it, as just that, "flight", withouot any qualifiers ("free flight").

KEvron

reversal: no, not even via semantics can it be considered flight, because it never leaves the ground. it moves the position of the arm to which it's attached, but the arm remains fixed to the ground, flightless. propulsion, not flight.

Edited December 25, 2011 by KEvron

[locoworks]

I think a flying machine made with 100% lego (no balloons, no non lego powersource or propellers) may be possible, but with a catch. It's not with todays technology, or is it?

Anybody heard of Eric Laithwaite? If not then search on Youtube for Eric Laithwaite Christmas lecture. It's in several parts, should total about an hour in length.

In short his ideas about gyroscopes, precession, angular momentum and so on may lead some to believe that a spinning flywheel being moved in a particular way could generate a linear force, maybe enough to lift something off the ground without the need for propellers, jets or rockets, it would just seem to whirr and hover inside a completely self contained box. Now, most people in the scientific community still laugh at this. Eric himself was treated very badly and "cast out" as a heretic for this lecture. After all how can you generate a force in one direction without touching anything or throwing something out very fast in the other direction? Sounds like it shouldn't happen, but then there are one or two things that he demontrates in those lectures that shouldn't happen, like a skinny boy of primary school age lifing a 20lb spinning weight on the end of a pole at arms length. Now based on these ideas me and a friend built a device that generated up to 30 grams of lift. It's just a pity a couple of powerpuller wheels and buggy motors weight more than 30 grams but as a proof of concept, it makes me wonder if there really is something to this.

i don't think anything made solely from lego would fly. the motors don't have enough power to give a suitable power to weight of any contraption. and with the power needed the lego itself wouldn't take the strain.

[KEvron]

i don't think anything made solely from lego would fly. the motors don't have enough power to give a suitable power to weight of any contraption.

then leave the motor behind!

KEvron

[allanp]

For it to truly be flight, then it must ALL be off the ground, the countereight and framework included. This plane is like a see-saw or teeter-totter. Weight on one side makes the other side effectively weightless, requiring only a tiny push off the ground to lift. That is not flying, but that is exactly what is happening here.

i don't think anything made solely from lego would fly. the motors don't have enough power to give a suitable power to weight of any contraption. and with the power needed the lego itself wouldn't take the strain.

They have plenty of power THEORITICLY to lift there own weight, it's a question of efficientcy. Using a gear rack or winch, a lego motor can lift itself plus a substantial weight added too it. Bear in mind that with Eric's ideas i'm not talking about using propellers or turbines or wings to generate thrust and lift. That requires huge amounts of power for lego. Eric was talking about centrifugal forces and precession. If you put a power puller tyre on an old ungeared lego motor and spin it up, you will see there is enough centrifugal force there acting an all directions to stretch the tyre increasing it's diametre quite alot. If there was a way of redirecting all those outward forces into one direction, like up for example, I think you would see it take off quite easily! Seeing as it's the festive season, I urge you to watch Erics christmas lecture on the matter. Some very interesting stuff.

[Blakbird]

I'm sorry, but as an aerospace engineer I can say unequivocally that this model is in no way whatsoever "flying". Yes, the props do produce a certain amount of lift, but they are not lifting the weight of the model; they are only lifting the delta between the model weight and the counterweight. Neither is there any effective control system. The model is only stable because of the wire which adds a force to retain directional stability. Without the wire, it could not lift off and even if it could, it could not fly in any direction because it has no control surfaces and no way to control counter-rotating torque. If I was hanging from a wire and blew really hard to make myself spin, that wouldn't be flying either, but it would be completely analogous to what this model is doing. The actor hanging from a wire in a stage show of "Peter Pan" isn't really flying either, even if he/she happens to be using a fire extinguisher for thrust.

Don't get me wrong, the model is cool and this is the best that can be expected from a LEGO model. Although, the props are not LEGO so even in that respect the model is not an example of LEGO flight.

If I was allowed to use R/C motors and props, I actually could make a LEGO model fly. It would take a lot of power but it could be done. It would be cheating though.

[DLuders]

To all doubters:

Do a Google search for the term "Flight", and pick whatever online dictionary you like. Quote verbatim some text that refutes what I quoted from the Wikipedia definition of "flight". Those who claim that the model is not "flying" are basing their statements on their own opinions, not official definitions. Let's use scientific principles and be precise about exactly what "flight" is and is not. Thank you.