I am just curious.

What is the biggrest concern if worried about crashing?  Well that the props stop turning and it falls from the sky.

That is the going idea about what happens to a UAS as it loses power for whatever reason is that it will just fall and indeed it will.  I alwasy thought that to be the case for any chopper but while I was researching some physics about flying a chopper, I found out that while the common collective thought is that a powerless helicopter would just drop like a rock, it is not the case.

In fact, to get your helocopter pilot's license you have to practice this powerless landing several times before you are granted a license.

When a helicopter loses it's power, the props go into what is called an "auto-rotation" and you can easily land a helicopter without power with this auto-rotation that I guess is somehow caused by the pressure of the air against the prop and is designed to make it spin should you have complete engine failure.

http://www.todayifoundout.com/in ... ed-safely-this-way/

I would guess the smart ones know where I am going with this.  Why is it that if a helicopter can auto-rotate while falling, can't a quad and specifally a UAS be designed to have auto-rotation?  Maybe not.  I'm definitely far from an engineer and I know DJI has the best in the world working for them but I would be interested to hear what the reason is that it can't.

Here is a video of a pilot landing with esentially no power.  Now they come down fairly hard but not hard enough that if they didn't pull up at the end it wouldn't crash and cause a ton of damage.  You can see that it might not be pretty, certainly would be a little scary but that's if you're in the friggen thing.  It would certainly save the craft.  But when the pilots do these tests they run the idle down to almost nothing so they can pull up at the end or in the eventuality that something goes wrong, the pilot teacher can riight the bird.

golf_sierra@lib Posted at 2016-4-28 02:56
Autorotation keeps the props spinning, that is true. When landing a helicopter without engine, the p ...

So by your logic , it would on a single prop helicopter?  

The landing, while done with a tiny bit of idle is done to emulate a full power loss so it doesn't matter if it's fueled by gas, electricity or urine, the act of falling out of the sky has been engineered by helicopter designers to make it so that the air pushing upwards against the props, causes it to spin the props so that the helicopter will do it's version of "gliding" even though I fully understand that it's not actually gliding.

It would seem to me, the biggest hurdle with quads, or hexes, or octos or whatever is getting the counter and clockwise props to do the right thing but it doesn't sound like it would be an engineering masterpiece to figure out a way.

I also understand that having a pilot in there certainly would help with a real life pilot and its passengers to survive the fllght but with automated UASs, we don't need perfection.  If we can get a version of this auto-rotation during a power outage, it would not only GREATLY increase the likelihood of saving the bird, but also from causing some possible devastation below. Both of those reasons seem good enough to try for it.

So my question is why in the RC world have I never seen it on a single prop either?

The fact that it's electronic vs gas powered is lost on me as the whole issue is that there is no more power so what was keeping it aloft to begin with is now not a factor, right?

I'm just saying if I threw a P3 or P4 out of an airplane it will fall like a rock but if you had a newer helicopter fall from the sky without a pilot, yes it would miss the runway but the helicopter would float down, not drop.  At least from the way I understand it but I got all my information from a couple websites I just now read including the one I linked to.

I am not saying you are wrong at all. I am just saying I don't understand the logic of what you're saying.

First, helicopter props have much greater inertia than the quads. Second, Helicopter has a variable pitch which can be changed in the air and allow aircraft to make a slow and soft landing.

DJI-Paladin Posted at 2016-4-28 03:19
First, helicopter props have much greater inertia than the quads. Second, Helicopter has a variable  ...

I understand the first part and am not a physicist so if the answer is that it just can't be done to a quad for whatever reason, I'll have to take it on faith.

However, not looking for a soft nice landing.  From 300 meters in the sky, a hard rough landing that only breaks the gimbal is a winner.

Very interesting discussion.
Certainly in Australia one of the biggest problems that the Civil Aviation Authority has with drones is their potential to do damage and injure people in the event of failure.  That's why they have the non fly within 30 metres  etc etc
I wonder if an easier way to save a falling drone and people underneath would to have an emergency parachute that would pop out the body in the event of a catastrophic failure and guide the drone gently to the ground. I'm sure that our engineering experts at DJI could come up with something.
All said half in jest - but - mmm!!! - might work.
I haven't looked for a while but I think there are some 3rd party companies that sell parachutes for drones.

ArtistFirst Posted at 2016-4-28 20:20
I understand the first part and am not a physicist so if the answer is that it just can't be done  ...

A real helicopter rotor has controllable pitch and as you are coming in to do your autorotate landing you are able to change the pitch to provide lift.
Our props are fixed pitch - you can't change the pitch so you can't get any lift and you keep slamming down whether your props are spinning or not.

petevandra@msn. Posted at 2016-4-28 18:32
Very interesting discussion.
Certainly in Australia one of the biggest problems that the Civil Avia ...

There are some more expensive drones where the parachute either comes standard or as a modular addition but this is not future tech you are describing.











Not sure why these were all slovic.  Anyhow, this was just on a quick google search and copy/paste but the parachute technology has been around and is being used for the more expensive devices with $50,000 cameras, and $10,000 birds.

Either way, auto-rotation baby! It's the future. ;)

ArtistFirst Posted at 2016-4-28 11:20
I understand the first part and am not a physicist so if the answer is that it just can't be done  ...

The variable pitch on the chopper blades means the pilot can angle them so that they act just like a wing on a fixed wing aircraft. Picture it as a rotating wing giving lift through forward movement of the aircraft. The UAS on the other hand has fixed pitch propellers. If a chopper has not enough forward speed then it will stall and drop like a UAS

Aardvark Posted at 2016-4-28 18:41
The variable pitch on the chopper blades means the pilot can angle them so that they act just like ...

Again, not an engineer or a physicist but why in God's name would they make a fail safe like auto-rotation left to the pilot?  

It would seem to me, like in most things, if you know the chaos, you can try and control it.  Couldn't it be designed where they know it's going to be falling and therefore when the power is gone X happens (and whatever X is) is the thing the pilot does to make the auto-rotation happen.

I see what you're talking about and if you look at the image I showed, that certainly looks like what happens but isn't that what happens when a helicopter flies.

Somehow, the spinning causes air to push up on the props giving lift to the bird but in a straight down motion (or in a hover motion) it's not using whatever mechanisms cause it to tilt forward or backward but rather just not fall as fast.

Seems to me, a laymen, that it wouldn't take an engineering feat of genius to develop a helicopter (or UAS) to cause that motion on it's own.

I have gotten too far into this discussion without the knowledge to be not talking out of my arse which I am already doing.

It was only 2 hours ago, that I even learned that a regular helicopter had this auto-rotation but I yield to anyone that knows about physics or flies a helicopter. I am working strictly on logic and logic to me dictates that if the air can be used to cause the rotation of the blades without power, that it could be done without a pilot and it could in theory be done in a UAS (drone).

I've never seen it on an RC single prop either which probably lends itself to it not being possible but there really has never been a multi-billion dollar company behind any RC hobby before I don't think.  I believe the innovations we will see in the UAS market over the next decade will be the biggest tech in the world and it's funny how infant it is right now.

We will one day look back at a conversation like this and laugh how full of rudiment it was.

A helicopter has a mechanical link from the pilot control stick to the main rotor called a swash plate.
The swash plate allows the main rotor to alter pitch of the blades and angle of the entire main rotor. This mechanical link wheather in full scale or model aircraft is what allows auto rotation.
Auto rotation in its simplest form is the ability to alter blade pitch and rotor angle while unpowered.
A quad copter does not have this.
A quad copter is controlled by one thing and one thing only, independent control of each motor rpm.
Even though each craft can hover and fly in a similar fashion they are completely different machines.

Drone Man Posted at 2016-4-28 19:01
A helicopter has a mechanical link from the pilot control stick to the main rotor called a swash pla ...

That makes more sense.  It still is just another way of saying it can't be done because this is how it's done in a real helli which it sounds like you know a lot about.

However, to call them COMPLETELY different machines, however different they are, is a bit stretched dont you think?

I mean a Tesla and a Corvette are two very different machines but they are hardly completely different machines.  

"if all the scientists around the world work all day for the next 100 years, maybe man will achieve flight" - NY Times

3 weeks after that, the Wright Brothers flew Kitty Hawk.

I actually paraphrased the Times there but they wrote it after one of those funny and goofy failures of flight that were taking place before the Wright Brothers figured out the puzzle.

That's where we are now is missing some pieces to the puzzle.  On top of it, technology is exponential.

If we don't kill ourselves, the technology of the next 50 years will make our parents look like they lived in the stone age.

Think about it.  If you believe in Christ, your great great grandmother traveled the same way he did and lit the area he was eating the same way.  That lasted for 1000s of years.

The last 100, now we can fly all across the world, have landed on the moon, can talk to each other on something that wasn't even a thought 50 years ago (the PC), and of course all the other technologies we now have.

It will not slow down, it will increase at a rapid pace and the reason for it is innovation breads more innovation.  

I don't claim to know what I don't know but what I do know is that the helicopters that those guys are landing in that video look archaic to me and I believe that in the next several years, drones that don't crash when they lose power will be obvious, not spectacular.

I'm like friggen Edison over here.  Someone give me an elephant.

Upon power loss in a conventional helicopter (real or R/C) you would normally put the rotor blades to negative pitch.  As the craft starts to fall the rotor would gain rpm.  At a determined distance from the ground you would start to flare and at the same time start giving positive pitch.  The rotor system would loose rpm but you would get 'lift' back in exchange.  If you get it just right you should have a relatively safe landing.  A quad because of its design cannot do this.

ArtistFirst my friend,
You are over thinking this waaaay too much,
Your splitting hairs and talking semantics, your going off in directions that are irrelevant to this discussion.
"Tesla and a Corvette"
"Wright Brothers flew Kitty Hawk"
"Christ"
This is not a Philosophy forum its a drone forum.
Just take my statement at face value,
One craft can auto rotate and one cannot.
And in fact they are completely different machines,
The only thing they do the same is leave the surface of the earth, they both
have the ability to fly.
They are completely different in concept and execution.
My .02

you can auto this type of multi rotor but its not the same as we fly for video or photos

Drone Man Posted at 2016-4-28 22:04
ArtistFirst my friend,
You are over thinking this waaaay too much,
Your splitting hairs and talking  ...

"Your splitting hairs and talking semantics"

...... well that depends on what you mean by semantics

mark.mwilliams7 Posted at 2016-4-28 08:18
you can auto this type of multi rotor but its not the same as we fly for video or photos

https://yo ...

wow...that thing is amazing.

I flew my Phantom 2 V+ to about 400' and inexplicably it dropped from the sky. Signal lost, no control, no video feed, no video recorded. I think I s#!t my pants.

One of the landing gear mounts popped out and the battery was ejected but otherwise it survived fine.

I always figured that some combination of weight distribution and drag/autorotation kept it right side up as it fell (I had prop guards on it). Also, the fact that it "landed" on an artificial turf field softened the impact.

I never figured out why it happened but my closest guess is that the battery was not seated properly and came loose during flight. One of the two batteries didn't quite always snap into place easily.

Nothing too dramatic in the video but the point at which it stops it the point at which it just dropped like a stone. (Skip ahead to about 1:00.)

Video Link:
https://goo.gl/wBzh6L

Drone Man Posted at 2016-4-28 20:04
ArtistFirst my friend,
You are over thinking this waaaay too much,
Your splitting hairs and talking  ...

COMPLETELY different they are not.  Very different, sure.

As far as philosophy is concerned, to a philosopher, it exists in everything and in that vane, I am making a point and the comparison of a Corvette and a Tesla for example is a perfect example.  Someone said because it's electric it wouldn't work but because we are talking about non-powered flight, it makes no difference.

And a Tesla and a Corvette are two completely different but also exactly the same in that they are cars.

An RC Helicopter is still a helicopter whether powered by electricity or gas, or coal or solar.

I was just using Christ as a Metric since most people can understand the time-frame and the exponential nature of technology.  All of the crazy technology we have was essentially invented in the last 20-30 years and there was nothing for 1000s.  You do the math.  If you don't understand what I am getting at, that's cool, but it doesn't make the philosophy of technology, a non-thing.

With all due respect, I don't think I'm overthinking anything, I think you are under-thinking, even if you have a great understanding of the physics involved that I do not.

ArtistFirst Posted at 2016-4-30 10:01
COMPLETELY different they are not.  Very different, sure.

As far as philosophy is concerned, to a ...

This discussion makes as much sense as .. planes can fly, why can't my car?

Find a helicopter that can autorotate with a fixed pitch rotor and come back to the discussion.
It will be hard though.  I can't think of any fixed pitch helicopters.

Until you have a controllable pitch quadcopter, there's no point to this discussion .... but you've already been told that several times.

labroides@yahoo Posted at 2016-4-30 08:12
This discussion makes as much sense as .. planes can fly, why can't my car?

Find a helicopter that ...

Well then maybe the answer is to not have the rotors fixed.

To say, a helicopter can fly, why can't my car to this discussion is disingenuous and untrue parallel to prove your point and I won't engage a conversation with someone that will do that.

Naysayers never innovate, they are hurdles.

ArtistFirst Posted at 2016-4-30 12:16
Well then maybe the answer is to not have the rotors fixed.

To say, a helicopter can fly, why can ...

Then why don't you go away and build a drone that can auto-rotate and prove all of the people in this thread wrong? I suspect you are one of those dreamers who think the hard part is coming up with the idea, and the execution is a minor matter. Over here we call those people wankers.

ArtistFirst Posted at 2016-4-30 08:01
COMPLETELY different they are not.  Very different, sure.

As far as philosophy is concerned, to a ...

There is your answer right there......"physics" You do not have an understanding.
Whichever way you drop a stone, it will still be a stone and it will still fall like a stone.

If you're asking why the current, fixed-pitch type of quadcopter can't autorotate, the answer has been given many times.  As stated, a *real* helicopter (or an RC helicopter) has a swashplate which is used to control the pitch of the rotor blades at all positions throughout its rotation.  The "collective" portion of a helicopter's controls moves the swashplate uniformly up or down to control the pitch of the main rotor identically at all points.  Watch a helicopter lift off sometime.  The pilot will increase the throttle, the blades will spin faster and faster, and then as he "raises the collective", the pitch angle of the blades increases and the aircraft will lift up vertically.  Decrease the collective, and the blade angle decreases, resulting in less lift, and the aircraft will descend (basically).  BTW, this has *nothing* to do with forward airspeed, which is controlled by the cyclic control.

In a loss of power, or retarded throttle for practice, the pilot "dumps the collective" and as the aircraft essentially falls, airflow over the rotor will cause it to continue spinning (or increase its rotational speed).  Just prior to landing/crashing, the pilot now increases the collective, using the stored energy of the rotating mass to keep the rotor turning, and increases the blade pitch angle, which results in lift, preventing the crash.  BTW, on some helicopters, you have to dump collective *very* quickly when power is lost or this won't work.

Forward flight uses cyclic control of the swashplate, tilting it cause the blade angle to be more at some points in the rotation and less at others (and there's the matter of gyroscopic precession, etc., which determines where in the rotation the blade inputs have to be effected by the plate).

Now, if you're asking "why can't someone make a quadcopter that has variable pitch blades and a collective so that it can autorotate", well...have at it!

Geebax Posted at 2016-4-30 10:58
Then why don't you go away and build a drone that can auto-rotate and prove all of the people in t ...

I actually do build drones but I don't innovate them.

I do innovate in a lot of other areas and work extensively with product specialists at companies all over the world including Lip Sync and Goldcrest in the SoHo district of London so I know Europe quite well thank you and I can promise you that they don't call philosophers, innovators, inventors and entrepreneurs wankers.

In fact, using the word wanker is pretty much only song by wankers in the otts.

At first it was just a question that I didn't know the answer to but the responses has forced a "really you guys can't imagine innovating something this simple" discussion.

In fact I found a video, and I wasn't even looking of a drone currently on the market (might even be the Matrice 600 that if it loses two of its rotors, the whole thing starts to spin and becomes the unit becomes part of the rotor system but that's just science fiction to wankers like me. The true wankers are again, people that use the word in this day and the people that fail to have vision. It's not even vision of the future.

I would love to have a discussion about the future application of aerial automation with you but you would just say "ummm, the rotors are fixed, how will I ever be able to serve a beer on a UAS, ya wanka".

Some of my best friends in the world are Brits and they are usually some of my favorite people in the world but you fit an anti-American "this is what we say and do across the pond" sort of character type that exists over there that I can't stand. Wanker? Really? Lol.

EDIT:

Went to search for the video of the hex or octo that spins down while losing up to three motors/props but I couldn't find it but it's a new one and it's bad arse.

Here is one from 2013.  It's a good thing that the people with brains, that don't go around insulting people for absolutely no reason, are innovarting and being wankers.

This was many years ago and you would probaby call it impossible.  It's a quad that can spin it's way down to safety after losing a prop.

I understand that having a bird drop with one missing prop out of 4 while being a pretty amazing feat, is not the same as NOT having any power at all but the algorithm in a flight board to have it spin and adjust properly without the other props are brand new algorithms so I have ZERO doubt that there will be a gliding down UAS in the next generation or two.  Keep dreaming Mr. Jobs.



hey look, anothe wanker



I found another wanker.  Now keep in mind, I only heard of auto-rotation on this first post so all of this stuff I am currently posting is what I am finding now with Google searches which shows that a) my hunch is correct that b) it is only a matter of time before they figure out how to get auto-rotation on a fixed wing multi rotor, including a quad.  They exist already for unmanned singe props.  The key is to having the rotors spin backwards to act as gyros and provide just enough lift to keep the bird from falling like a rock but instead softer so that you want have a full catastrophy so apparently my thought is not only science fiction but exists. Wanker?

ArtistFirst Posted at 2016-4-30 19:26
I actually do build drones but I don't innovate them.

I do innovate in a lot of other areas and wo ...

You asked the question "Why can't our Phantoms glide like a chopper after a power loss?"
It's been answered by 8 of  the posts in this thread and despite no knowledge of the subject, you've dismissed them all and diss anyone silly enough to continue to explain the very simple concept.
I have to concur with Geebax on this one.
You fit the definition emminently.

labroides@yahoo Posted at 2016-4-30 18:18
You asked the question "Why can't our Phantoms glide like a chopper after a power loss?"
It's been ...

Well here is the thing.

I just posed the question to start the discussion and to the people that answered nicely and intelligently, I took it as an interesting conversation and nothing more.

Since then however, and frankly, and especially because you resorted to name calling, I went to see if what seemed logical to me was.  I usually find logic to be a great mediator for truth and logic told me that if it's possible to use wind to auto-rotate a helicopter that logic would dictate that even if different, there must be a way to use the wind (a power source) to help control the fall so that a 300 foot drop wouldn't be devastating to the bird.

Now that logic, as per the videos above, and another one on a new bird that I can't find again, shows that thatit is not only a sound idea, but existent so why again am I so wrong that it's possible.

I knew I wasn't wrong that it's possible because most things are possible when brilliant minds go to work on them but I didn't know the physics behind it.

It's definitely happening with the non-fixed wings unmanned sing prop choppers, every year apparently.  

ArtistFirst Posted at 2016-4-30 20:33
Well here is the thing.

I just posed the question to start the discussion and to the people that a ...

"However, even an airline pilot who has served for 50 years including a stint in the airforce and with a good understanding of aeronautics and physics might not know that a fixed wing multi-rotor with backward spinning props, can slow down it's descent but that appears to be the case now doesn't it?"

If you think that's what you've been looking at you are sillier than I thought.
A multirotor with backward spinning props will only go downwards and very quickly.
Algorithms to distribute power in a way that allows a partly disabled drone to descend safely has nothing to do with autorotation or spinning props backwards.

labroides@yahoo Posted at 2016-4-30 18:46
"However, even an airline pilot who has served for 50 years including a stint in the airforce and w ...

*Of course alhgrothims don't make a difference as it pertains to auto-rotation but my point was that the algorithms put in the flight baords that let it do that were not existant forever and someone had to engineer it.  That was the point.

Well the discussion is about powerless birds so flight boards and ESCs and motors don't really matter for this discussion.

As for me being silly for saying that the method for a fixed wing multi-rotor to slow the descent of a dead bird is not mine. I have learned it from the minor research I've done to satisfy my curiosity.

But on a free-fall descent of a multi, it requires the ability of the drag to cause the props to spin backwards (all of them) in order to make it more of a "glide".

I didn't make this up. I don't know this as fact because of some knowledge, it's just what I've read on several occasions and in the videos that are up there and all over the internet.

I am merely spewing back what I have read (over the last half hour) and since these guys seem like they know more about it than you or I, I am gong with what my eyes see as opposed to your deadpan desire to argue something that it looks like you don't know a whole hell of a lot about.

I don't claim to know these things but I certainly know just based on what i've seen that it's at least not a crazy bat-shite idea.

At the end of the day, it might be impossible.  I am merely posing the question and discussiing it and you had to go get all nasty about it and me being me, got my back up.

mark.mwilliams7 Posted at 2016-4-28 20:18
you can auto this type of multi rotor but its not the same as we fly for video or photos

https://yo ...

Now this is correct.  The trick would be to do just that.  Again, might not be possible and I am definitely not an expert but something down this road needs to happen.  With the "Drone Revolution" happening, we can't have these things falling full speed from the sky or it's gonna get nasty one day so a failsafe in the event of power-loss should be in the discussion.

helidan Posted at 2016-4-28 19:40
Upon power loss in a conventional helicopter (real or R/C) you would normally put the rotor blades t ...

Are you sure though?  What about this free-falling quad?  It's far from perfect, but it's not a rock and maybe a start?

When a helicopter goes into autorotation, there is a pilot (the brain) who still have control of the chopper and can initiate the appropriate steps.  In a Phantom class UAV when the power goes out, so does the brain.

The brain is what keeps the real helicopter under control.

If you did have power and had a functional IMU / ESC system you could likely program the system to spin the props enough to allow the IMU to keep the craft level.  Remember, in a Phantom class UAV, it has no INHERENT flight stablilty.  I depends entirely on the computer system to keep the rotors turning at the right speed.  When you autorotate a model RC helicopter, you keep the power going.....

But if you have power, why not just land the craft in a normal mode.  Just like the Phantom does when the voltage begins to drop.

If you don't have power, you can't control the craft, you can't 'autorotate' (and remember, I am not talking about a 'real' autorotate with the swash plate / collective interaction).  So why bother?  It is an function of a multirotor UAV that there is no inherent stability - it REQUIRES active control by the system.  Your free fall video freely admits that 'it doesn't always work'.  And that thing has an aluminum frame.  It can crash a wee bit harder than a Phantom and 'survive'.  So, you still want to have an emergency controlled descent - you need a separate battery, maybe a separate IMU system depending on how many failure modes you want to protect against.

Now the thing weighs 5 kilos, has a flight time of 3 minutes and costs $3000.  You're probably not going to make much money on it.  Engineering is ALWAYS about two things - physics and compromises.  You need to read up on both.

ArtistFirst Posted at 2016-4-30 12:32
Are you sure though?  What about this free-falling quad?  It's far from perfect, but it's not a ro ...

Yes very sure, as people have been trying to tell you.

WetDog Posted at 2016-4-30 22:15
When a helicopter goes into autorotation, there is a pilot (the brain) who still have control of the ...

You definitely know more than I about the subject so don't take my question as anything more than a question.

If it is imperative that there be a pilot in the heli doing the autorotation of a heli than how do you explain the video I posted that shows a litany of hellis in a yearly competition where landing in a specific area on a free fall nets you points where someone is always a winner but all of the hellis rotate down?

ArtistFirst Posted at 2016-4-30 03:33
Well here is the thing.

I just posed the question to start the discussion and to the people that a ...

Your autorotation contest video demonstrates *precisely* what we've been talking about...every one of those birds has a SWASHPLATE which controls the pitch of the blades.  No pitch control -> no autorotation capability.

See all those linkages underneath the rotor hub?  That's what allows the swashplate to control the collective and cyclic pitch of the blades.

RV7 Flyer Posted at 2016-5-1 06:06
Your autorotation contest video demonstrates *precisely* what we've been talking about...every one ...

Let's get some swashplates up in here. ;)

ArtistFirst Posted at 2016-4-30 16:54
Let's get some swashplates up in here. ;)

Did you not see the video of Curtis Youngblood flying that crazy thing, posted above?  It appears that all four rotors have swashplates, which lets him do all those wild stunts (Curtis is world famous in RC helis, btw).

IF you had a way to apply power (maybe a reserve battery or something) just prior to impact, you could likely autorotate that thing.  But you have to have a way to change the blade pitch, which means, for an electrically-powered quad, uh, electricity.

http://www.curtisyoungblood.com/

"Developer of the world's first single motor collective pitch qaudcopter"

RV7 Flyer Posted at 2016-5-1 10:07
http://www.curtisyoungblood.com/

"Developer of the world's first single motor collective pitch qaud ...

I looked at that thing and the first thing I saw were belt drives to the props and a whole lot of complicated mechanics just to make it work. The four motor fixed-pitch design of the Phantom is elegant in comparison to that design.

Geebax Posted at 2016-4-30 17:10
I looked at that thing and the first thing I saw were belt drives to the props and a whole lot of  ...

True enough, but for a first-generation 4-rotor cyclic control system, it's a start.  I'd expect next-gen versions to have individual drives or perhaps drive shafts from a hub, etc.

Essentially, this looks like an early prototype of what can be done...I'd fully expect refinements and improvements in later version.

Question for *this* thread is...can it autorotate?