Flight using Lego

[1974]

Great, now attach the batteries to the superstructure

Anything is impossible if you don't try.

That's probably not what you meant

[Zerobricks]

Guess what guys... M motors can fly too!

[Lost_In_Noise]

Good job, Jerry. Too bad about the RC motor. But still, it can't contain the power source, so no real lego flight yet...

[Zerobricks]

Good job, Jerry. Too bad about the RC motor. But still, it can't contain the power source, so no real lego flight yet...

By that logic electric locomotives also arent legit?

[anton1678]

Well, at least it is now known that LEGO can fly, even if it does only barely, and without the battery box in the air.

Unlucky with the RC motor, hopefully LEGO will release a "helicopter kit" (probably a battery box and 2 contra-rotating rotors, basically on one self-contained plastic box)

Yes, It would be dangerous, but not if contained in a cage, like fan blades.

[zux]

Well, at least it is now known that LEGO can fly, even if it does only barely, and without the battery box in the air.

It cannot since examples above show slow downwards motion, not upwards.Throw a brick - it will have same "flying" effect.

[anton1678]

It cannot since examples above show slow downwards motion, not upwards.Throw a brick - it will have same "flying" effect.

Though it was shaky, on the 'increased to 30 volts' you could see unbalanced upward flight

[Zerobricks]

So after popular demand I gave it a shot with a quadcopter. It's so very close, but the motors soon lock up and overheat.

All in all I think I proven Lego can fly, but the motors have to be pushed to destruction point (and beyond, RIP my RC motor ).

For now I am giving these exeperiments a stop before i break more stuff.

[Meatman]

I wouldn't consider that to be proof of legitimate flight.

[D3K]

How about this:

Using one RC buggy motor in "front", and a LiPo batterypack as a sort of counterweight in the back (I don't have one, so I don't know the weight of it). By using the fan blades ZBLJ has been using, and this setup, maybe with other gear ratios, maybe one could get it to lift off? Just a little? Maybe? Probably not...

[Zerobricks]

I wouldn't consider that to be proof of legitimate flight.

And this?

So this is what I managed to record:

How about this:

Using one RC buggy motor in "front", and a LiPo batterypack as a sort of counterweight in the back (I don't have one, so I don't know the weight of it). By using the fan blades ZBLJ has been using, and this setup, maybe with other gear ratios, maybe one could get it to lift off? Just a little? Maybe? Probably not...

Nope...Not with those blades, not with so many gears, not without anything stopping it from spinning around.

[Meatman]

I think everyone wants to see something actually liftoff from the ground. Not tossed into the air. If that were the case, then this video is also confirming flight.

[D3K]

Nope...Not with those blades, not with so many gears, not without anything stopping it from spinning around.

That was never the intention

By using the fan blades ZBLJ has been using,

As I see it, one of the main problems is still the one-way design of the fan blades, making it impossible to make a contra-rotating design...

One could probably lessen the amount of gears used as well, I don't know, it's just an idea that came to mind seeing your (tethered) quadcopter.

I applaude your attempts! I feel we are one step closer to seeing it fly! Although I highly doubt controlled, sustainable flight is at all possible with the current parts (as in, we won't see a 100% LEGO RC chopper or plane anytime soon)

[Blakbird]

I think this topic helps prove that the only way to make LEGO fly is to be very liberal with our definition of the word "flight" or the word "LEGO". By way of explanation, I offer the following questions:

• Is a model hanging from a wire flying?
  
• Is a model attached to a balloon flying?
  
• Is a model powered from the ground flying?
  
• Is a model taped to an R/C helicopter LEGO?
  
• Is a model using R/C motors and batteries LEGO?
  
• Is a model covered in Monokote LEGO?
  
• Is a model with an APCP rocket motor attached LEGO?
  

None of these questions has a definitive answer and they are all therefore subject to interpretation (as is clear by this topic!). However, in my opinion the answer to all questions is "NO". Balloons could more accurately be called "floating" as can other lighter-than-air craft. Unpowered models can be called "gliding". Parachutes are "falling with style". Traditionally, we would only call a craft "flying" if it met the following qualifications:

• Leaves the ground (any altitude)
  
• Remains aloft (can maintain altitude, not just fall. Climbing is a bonus.)
  
• Supports it own weight aerodynamically
  
• Provides its own power for lift and propulsion
  
• To be practical, should also be controllable although I'd be willing to call a LEGO model "flying" even without controllability
  

Airplanes, helicopters, gyrocopters, and even hovercraft meet these requirements. Balloons, hang gliders, parachutes, and boats do not.

Concerning the argument "you can never know until you try", this is a good epithet for encouraging perseverance and discouraging quitters. However, it is also only applicable to topics which are unknown, uncertain, or misunderstood. Many things we certainly do know without trying. If someone says to me, "I can run fast enough to escape the Earth's gravity and fall into the sun", I can say "no you can't". When they say "you never know until you try", I can say "Yes, I do know. I know exactly what the escape velocity for Earth is, and it is trivial to prove that no runner can ever achieve it." I don't need to do experiments to prove it. The science has already been done, the topic is understood. The same is true of flight. We've understood all the principles and equations governing heavier-than-air flight for a century. Therefore it is easy to show that LEGO flight is not possible without ever actually trying it. In fact, LEGO is very, very far from being able to fly. Even without an engineering background, anybody can use one of the many tools for R/C model builders to calculate just how much power is needed for a model of a given weight and wing area to fly. They are very accurate. You will quickly see that power 20x-100x greater than LEGO can provide would be required. However, I applaud the experiments which help demonstrate just how much actually can be accomplished with the existing parts.

I'm going to resist posting any more facts, equations, and numbers because some people just prefer to try it themselves, and I think that is a good thing. Trying things yourself is usually a better teaching tool than having someone tell you the answer. If anyone is actually interested in any real numbers or help with calculating the needs for a specific project, please let me know.

[Heppeng]

Do remember it was absolutely 100% proven using all the well established formulas that it was impossible for a bumble bee to fly, because its wings were too small to generate the required lift. Just as well no one could tell the bee...

[Lipko]

Do remember it was absolutely 100% proven using all the well established formulas that it was impossible for a bumble bee to fly, because its wings were too small to generate the required lift. Just as well no one could tell the bee...

You convinced me.

*burns diploma

[Blakbird]

Do remember it was absolutely 100% proven using all the well established formulas that it was impossible for a bumble bee to fly, because its wings were too small to generate the required lift. Just as well no one could tell the bee...

So you are saying engineering is pointless because sometimes people are wrong? Or you are saying that being ignorant of physical laws allows you to violate them? Whatever. Obviously a bumble bee uses different principles than an airplane. A LEGO airplane does not use different principles than an airplane. The "proof" you are referring to was never believed by anyone, nor was it intended to be. Everyone knows bumble bees can fly. The "proof" was just an illustration that there was a gap in our understanding of certain natural aerodynamic principles, and it was recognized that there was a gap. That gap has been filled. The same was true of the "sound barrier". It appeared that drag became asymptotic with velocity as you approached the speed of sound, and therefore theoretically it was impossible to ever exceed this speed. However, it was also known that an artillery shell went faster than that, so that revealed a gap in our understanding of drag. That why the Bell X-1 was shaped like an artillery shell; it was the only shape they were sure could go that fast. There is no gap in our understanding of what it would take to make LEGO fly.

[GuiliuG]

I'm fully interested by your equations and demonstrations Blakbird ;-)

[Lipko]

... sorry, wrong whatever

Edited June 23, 2014 by Lipko

[Lost_In_Noise]

Can't we just stop bashing, stick to the topic, and see just how far someone can push the current parts? It's like MythBusters, only with Lego instead of welding and stuff. Keep the pics and videos coming!

[Zerobricks]

Well for now I think we can give this topic a rest, because no matter how hard we try we will not reach the level of control/stability that is practical with current parts.

[Paul Boratko]

Do remember it was absolutely 100% proven using all the well established formulas that it was impossible for a bumble bee to fly, because its wings were too small to generate the required lift. Just as well no one could tell the bee...

You know what really makes a bumblebee fly..? A badminton racket...

[Blakbird]

You know what really makes a bumblebee fly..? A badminton racket...

Now there is something that can be experimentally validated!

Turns out the whole bumblebee thing is an urban legend anyway.

http://en.wikipedia.org/wiki/Bumblebee#Flight

[aol000xw]

The sad part is that Lego will never release a fly ready motor, because if it is fast and powerful enough it can become a circular saw. Not very child friendly. It will never release a battery powerful enough because that poses electrical/fire hazard risks. Even a proper propeller may prove too sharp and dangerous. So pure Lego will never ever flight.

So the real question is not if Lego can fly, it can´t. What is the bare minimum non Lego needed to achieve flight? I'd say propellers to achieve some hovering with ground batteries and motors for a real flight. Batteries can be ok with AA LiFePo cells and old style boxes.

Science: crushing dreams one by one since.. well ever. On the other hand dreams can't make Lego fly, science can. So I'd say thanks Blackbird for the sanity check.

[Blakbird]

So the real question is not if Lego can fly, it can´t. What is the bare minimum non Lego needed to achieve flight?

Now that's a very good question that it would be fun to explore. If you allow yourself unlimited R/C components, it would be fairly trivial to make a LEGO airframe fly. You just need lots of power (and wing covering). I have the components in my garage, maybe I should try it...... I think at minimum you need R/C Li-Po power supply, brushless motors, radio, speed controller, servos, and propeller. Pf remote is not adequate because of IR, battery box is no good because of weight and current limit, motors are no good because of low speed and weight. So you really need a full suite of R/C electronics but you could do the airframe with LEGO. It would be heavy compared with balsa or foam which means it would have to fly fast.

All of the above is talking about a fixed wing airplane. An airplane needs much less power to weight ratio than a helicopter, so it makes sense to tackle an airplane first. Stability is also much easier with an airplane.