Enough "lift" for helicopter flight

[trekman]

I was considering building a helicopter out of technic and was wondering is it possible to get enough lift to make a basic chopper airborne. I understand a little about the rotor profiles, but can a basic tilted rotor blade create the lift needed? Or do we face the age old problem of technic components starting to wear away before we see any lift off?

[timslegos]

Lego usually never gets off the ground . Goodluck though!

tim

[Blakbird]

I was considering building a helicopter out of technic and was wondering is it possible to get enough lift to make a basic chopper airborne. I understand a little about the rotor profiles, but can a basic tilted rotor blade create the lift needed? Or do we face the age old problem of technic components starting to wear away before we see any lift off?

Short answer: no way. Lego parts do not have an airfoil shape to make a proper rotor for lift, and they are not even flat plates. Even with a proper airfoil shape, you could never get enough torque through an axle to lift the weight of a LEGO helicopter. The best you can hope for is a mild breeze generator.

[AussieJimbo]

I'm only an amateur technic builder but I love seeing threads about trying to make Lego fly, this sort of ambition is what Lego is all about. Unfortunately as Blakbird mentions, the consensus I've seen in comments from expert builders is that it's just not possible. The forces and tolerances involved are just not achievable in a Lego-only solution.

Projects seem to stop there. I wanted to ask if anyone had accepted this limitation and built a Lego model around the flight critical non-Lego components and made it fly or is the Lego itself simply too heavy to get airborne.

Maybe staring out with a Lego canopy for an RC helicopter, then moving on to the rest of the body and tail boom whilst retaining the non-Lego engine, rotors and control system.

For a fixed-wing plane, could you build a sufficiently light but robust airframe to support the non-Lego engine and control surfaces to enable powered flight. This might just be fuselage to start with but I could imagine cloth/plastic covered wings or even a brick-built airfoil shape with vinyl wrap to reduce the drag.

From there thrust is provided by one or two of those cool mini jet engines (the project just got very expensive) and you roar into the sky on a wave of Lego awesomeness and wishful thinking.

:classic:

Edited October 3, 2011 by AussieJimbo

[timslegos]

Projects seem to stop there. I wanted to ask if anyone had accepted this limitation and built a Lego model around the flight critical non-Lego components and made it fly or is the Lego itself simply too heavy to get airborne.

the only form of flying Lego i have ever seen was a blimp with a huge non-Lego balloon with a tiny Lego observation deck attached.

tim

[AussieJimbo]

Cool, that's a start.

You could conceivably build a Lego motor and control system for a blimp or even rigid airship with Lego frame. The question then becomes how big does the envelope (balloon) need to be.

:classic:

Edited October 4, 2011 by AussieJimbo

[telecasterman]

There's one of Isogowa's creations that flies, albeit on a boom with the power functions battery box as a counterweight. Here'e the link:

I had tried to build a flying dragonfly using a similar technique, but it just weighed much too much. (So I cheated and used a second motor to make it go 'round...):

(I'll be damned if I can figure out how to embed the videos...)

Edited October 4, 2011 by telecasterman

[DLuders]

Yes, these videos are quite good!

P.S. To imbed videos on a Eurobricks forum, here are the steps:

1. Copy the URLs into your web browser.

2. Once the video appears on your browser, copy the new URL into your Eurobricks post.

3. Chop off (delete) any text that starts with &feature=youtu.be (in this case).

4. Cut and paste the URL into the "Insert Media" button at the top center of your post menu.

[Blakbird]

Projects seem to stop there. I wanted to ask if anyone had accepted this limitation and built a Lego model around the flight critical non-Lego components and made it fly or is the Lego itself simply too heavy to get airborne.

Maybe staring out with a Lego canopy for an RC helicopter, then moving on to the rest of the body and tail boom whilst retaining the non-Lego engine, rotors and control system.

For a fixed-wing plane, could you build a sufficiently light but robust airframe to support the non-Lego engine and control surfaces to enable powered flight. This might just be fuselage to start with but I could imagine cloth/plastic covered wings or even a brick-built airfoil shape with vinyl wrap to reduce the drag.

I admire your determination! I fly a lot of R/C helicopters and airplanes, and I also analyze real airplanes for a living. There is a very obvious theme here and that's the importance of minimal weight. Lego structures made from ABS and snapped together with no mechanical fasteners have a lot of disadvantages when it comes to achieving flight. However, when someone challenges me with a question like "is it possible?", the answer is always "yes". The caveat is, "how hard are you willing to try?". After 10 years flying R/C, I've stated that I can make any object fly with enough power. So you could indeed (for instance) build a LEGO Technic airplane fuselage, wings, and even flight control surfaces. You'd have to cover them so seal the openings. It would be really heavy, so you'd have to add an obscene power system and you'd have to use proportional servos. Take off and landing speeds would be very high. But it could be done!

Dluders has flown a LEGO rocket. Again, with enough power you can launch anything.

Helicopters get a lot harder though. The rotor and swashplate system can be simulated with Technic, but they just don't have the tolerances or torsional rigidity to support the required loads to generate critical lift. So what about if you used a commercial helicopter rotor system and made the body of LEGO? Maybe, but those rotor systems are made only to lift bodies with weights proportional to the rotor size, so the assumed weight is much lower than you could achieve with Technic. You could theoretically use a rotor head that is way too big in scale with the body. Helicopters also have a lot of vibration and require rigidity as well as light weight. I'm fairly confident that, with enough budget, I could make a flying helicopter with a LEGO body. It would not be a very good helicopter, but it would "fly", more or less.

I stand by my original statement that making an entirely LEGO (heavier than air) creation fly is probably impossible.

[Alasdair Ryan]

What about a plane with a rubber band in the prop?

web link

[trekman]

I found a couple of videos which create flight in some manner:

This one uses a helium type balloon to give the lift, and the lego motor for the propulsion

http://www.youtube.com/watch?v=eL35FH6y4HU&feature=related

This one, which is more interesting creates 4grams of lift from a lego motor, albeit with rulers as rotor blades. I just wonder could I improve the speed????

[MMR1988]

I've seen this thing in real, while I was at my "Lego-Dealer." A friend of him built this awesome thing.

The rotors are non-LEGO parts. The rest is made with Lego.

And yes, it is hanged up with a string.

Max

Edited December 28, 2011 by MMR1988

[AussieJimbo]

Thanks for the detailed followup, Blakbird. I agree with all of that.

After my post I checked out some youtube videos of pulse-jet powered R/C planes which is mad and awesome at the same time. Limited endurance and significant heat issues but it's a cheaper option than those cool mini jet engines.

I admire your determination!

Active imagination rather than determination. ;-)

I think the most likely outcome would be a search for any salvageable parts after you've put out the fire.

What about a plane with a rubber band in the prop?

web link

Might be able to do it, if the only Lego component was the propeller. :-)

I found a couple of videos which create flight in some manner:

(1) uses a helium type balloon to give the lift, and the lego motor for the propulsion

(2) which is more interesting creates 4grams of lift from a lego motor, albeit with rulers as rotor blades. I just wonder could I improve the speed????

Cool videos.

The creator of the second one has a fine approach for his experiment but needs to work on his maths skills (in his second test 204 - 196 = 8g of lift not 12g). That best test shows the mechanism developing just 4 percent of it's own weight in lift, leaving aside the need to build a body. Interesting but orders of magnitude away from being practical.

The balloon airship is a fun little model though. You can see that the maker is having trouble establishing neutral buoyancy. In real life blimps this is addressed by using inflatable air bags within the gas envelope:

http://en.wikipedia.org/wiki/Ballonet

I think you could address this with a Lego solution by using one of those motorized pneumatic pump assemblies to inflate and deflate an inner balloon within a helium balloon. The you get remote trim adjustment but of course the more weight you add the more balloons you need to lift it.

Lighter than air is really the only feasible approach for controlled Lego flight. I like the idea of DLuders rocket though. Maybe I should hunt out some of those old Estes rocket engines that have been sitting around for too long and build something for the next visit to my mate's farm.

:classic:

Edited October 5, 2011 by AussieJimbo

[DLuders]

I like the idea of DLuders rocket though. Maybe I should hunt out some of those old Estes rocket engines that have been sitting around for too long and build something for the next visit to my mate's farm.

:classic:

Yes, I can assure you that a Lego Rocket really can fly. Read all about them on MOCpages and get the Lego Digital Designer (LDD) .lxf files for two of them from my Brickshelf gallery. They were on display at Brickcon 2011 in the "Space" theme area.

[Finntech]

I've seen this thing in real, while I was at my "Lego-Dealer." A friend of him built this awesome thing.

The rotors are non-LEGO parts. The rest is made with Lego.

And yes, it is hanged up with a string, but only for "controlling" the flight.

Max

So this thing really does lift without any help? If it does, it is truly amazing because it must be quite heavy with all the motors and parts.

Regarding previous posts, I understood that this is probably not even possible. But here it is, right?

[Sokratesz]

I've seen this thing in real, while I was at my "Lego-Dealer." A friend of him built this awesome thing.

The rotors are non-LEGO parts. The rest is made with Lego.

And yes, it is hanged up with a string, but only for "controlling" the flight.

Max

Given the difficulties that the US army has in keeping their ospreys aloft, building a LEGO one would be even more impossible than a regular helicopter ;)

I like the idea of a LEGO platform that floats by means of helium balloons but steers with LEGO motors - although some sort of control over altitude would be nice.

- Sok.

Edited October 5, 2011 by Sokratesz

[DLuders]

Here is that

of the flying Lego Mindstorms Airship (Zeppelin):

"A unique view of LEGOWORLD Copenhagen 2011, Video made for the LEGO® Mindstorms® Group presenting the C5, a flying NXT blimp project from the BrickIt.dk team.

- MORE TECH DETAILS AVAILABLE HERE: http://www.brickit.dk/index.php?page=projects&id=8&step=2 .

- Filmed in Denmark at LEGOWORLD Copenhagen, on Feb 17th to 19th 2011.

- Video edited in Montreal, Canada."

Edited October 5, 2011 by DLuders

[allanp]

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.

[Alasdair Ryan]

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.

Em sorry alan but i fell a sleep reading your reply ,are you thinking of a fly wheel or a rip cord?

Edited October 5, 2011 by Alasdair Ryan

[allanp]

But.....how the fu......RIPCORD?!?!!!!!......Yup, you fell asleep alright! I meant flywheel, or gyroscope to be more accurate

Edited October 5, 2011 by allanp

[MMR1988]

So this thing really does lift without any help? If it does, it is truly amazing because it must be quite heavy with all the motors and parts.

Regarding previous posts, I understood that this is probably not even possible. But here it is, right?

Yes, you're right. It lifts up without external help.

Martin

[Blakbird]

Yes, you're right. It lifts up without external help.

Hmmm, I'm afraid I don't believe it. The weight is clearly being supported by a string. The rotors are only providing thrust. This thing has no control surfaces and therefore could not possibly hover without external support no matter how much thrust it has.

[MMR1988]

What do you mean with control surfaces? Ruders for controlling the flight?

Yes there are now such controls on it. It can only control the angle of the rotors. That's why it is supported by a string.

You can see the flight at Second 4.

Martin

[Blakbird]

What do you mean with control surfaces? Ruders for controlling the flight?

Yes there are now such controls on it. It can only control the angle of the rotors. That's why it is supported by a string.

You can see the flight at Second 4.

My point is that real R/C vehicles that hover (like helicopters) have adjustable throttle, adjustable pitch on the rotors, gyros, and many other electronics to keep them stable. Even so, the very best such vehicles I have ever seen (which cost many thousands of dollars) are nowhere near as stable in hover as this thing is. So either this is the best vertical flight vehicle ever made (impossible with no gyro or swashplate) or it is actually not being supported by the lifting surfaces. This looks to me like a "control line" model, which is quite common. Weight is carried by a string, and the motors only provide propulsion.

[Paul Boratko]

I am having a real hard time believing that those 2 propellers are lifting what appears to be 6 or 7 pounds of plastic...

And the reason why is because there is ZERO flex on the wings that the propellers are connected to when the thing lifts off of the ground.... They certainly don't appear to be heavily re-enforced to prevent flexing and like I said, there is ZERO. That is quite a bit of weight in the base of the vehicle those wings are connected to... Actually when it lifts off, the wings appear to still be bowing downwards from the weight at the tips of the wings, and it should be the exact opposite...

Edited October 7, 2011 by Paul Boratko