World's first manned flight with an electric multicopter

November 2, 2011 3:02 PM

World's first manned flight with an electric multicopter.
posted by atomicmedia (52 comments total)

I'd buy one.
posted by sarastro at 3:07 PM on November 2, 2011

Oooh, I've got a quadcopter here that I've been meaning to put together for ages. Now I'm all excited again.
posted by unSane at 3:12 PM on November 2, 2011

Man, I wouldn't be anywhere near those blades. Those dinky little brushless motors look harmless enough, but they will eat flesh like a raptor. In a crash he would be chopped to bits.
posted by unSane at 3:13 PM on November 2, 2011 [1 favorite]

Huh, I didn't know you could get a Cuisinart to fly.
posted by indubitable at 3:14 PM on November 2, 2011 [2 favorites]

I'm just wondering why nobody did this sooner.
Probably the batteries weren't good enough?
posted by localroger at 3:14 PM on November 2, 2011

Man, I wouldn't be anywhere near those blades. Those dinky little brushless motors look harmless enough, but they will eat flesh like a raptor. In a crash he would be chopped to bits.

Gives a real and immediate meaning to the phrase, "when shit hits the fan," doesn't it?
posted by indubitable at 3:15 PM on November 2, 2011

I'm just wondering why nobody did this sooner.

Combination of batteries and cheap brushless motors and open source Multicopter firmware finally becoming available, plus a critical mass of hobbyists tinkering with it.
posted by unSane at 3:17 PM on November 2, 2011 [3 favorites]

Finally, an explanation for those fucking crop circles.
posted by crunchland at 3:20 PM on November 2, 2011

I love that the landing gear is basically an exercise ball.
posted by polywomp at 3:22 PM on November 2, 2011 [3 favorites]

What does it say that I saw this link, thought "I bet this guy is German", clicked it, and found out he's German?
posted by nathancaswell at 3:25 PM on November 2, 2011 [2 favorites]

You can ride this AIR CAR around your home or school.
posted by darksasami at 3:27 PM on November 2, 2011 [7 favorites]

RC hacking is a hugely German preoccupation
posted by unSane at 3:27 PM on November 2, 2011

I suspect coordination of the blades would be an issue. I like the choice of landing gear too.
posted by ZeusHumms at 3:31 PM on November 2, 2011

This is a fantastic idea, and it's probably only been possible in the last five years. I can see at least three HUGE benefits for the intended market:

1) The computer control, gyro and/or gps feedback makes the craft child proof to fly - it just goes where you tell it, and stays there.

2) The rotors could be sized to supply 133% of the necessary power. That way if any one rotor failed on each of the four arms, the computer could compensate and the craft could land

3) This would be extremely cheap. The only moving parts are stock items, and the rest is just framing. Electronics are cheaper than swash plates

4) It could probably be knocked down to fit in a sedan. It's a general aviation dream come true!

The downsides are that it's going to always have a short range and low speed (the small rotors are necessary, but inefficient), but who cares - Hovercar!
posted by Popular Ethics at 3:32 PM on November 2, 2011

My guess is that it cost around $1000 to build (not counting prototypes).

Battery life is probably in the region of 5-10 minutes.

Everything it's made from can be bought at a hardware store or for peanuts from somewhere like Hobbyking.com.

I'm guessing the multicopter software is arduino running firmware based on something like this.

Flight failures are *extremely* common with this kind of stuff though. You would want a huge amount of redundancy built in, which reduces battery life and so on.
posted by unSane at 3:35 PM on November 2, 2011 [1 favorite]

(Battery life is 5-10 minutes but you may only get enough power to fly controllably for a minute or two -- they are gunning those motors flat out on big props)
posted by unSane at 3:36 PM on November 2, 2011

Moller's got some 'splaining to do.
posted by The White Hat at 3:41 PM on November 2, 2011 [1 favorite]

they are gunning those motors flat out on big props
They can't be going flat out. Multicopters need to keep some reserve so that they can throttle up each rotor when needs be to maintain stability.

I don't disagree that this thing probably uses a lot of power though. They've got the right idea with a (future) gasoline-powered hybrid, but I think it's still going to have a short range (minutes, not hours).
posted by Popular Ethics at 3:41 PM on November 2, 2011

I'm just wondering why nobody did this sooner.

In addition to battery and motor technology - it is programming logic combined with enough embedded processing power to allow the entire contraption to function fluidly with an intuitive control mechanism.

So - we have finally hit a sweet-spot.... nice...
posted by jkaczor at 3:42 PM on November 2, 2011

"This could be the future of flight, piloting a device as simple as a car." --- Yeah, how many times have we heard that before?
posted by crunchland at 3:42 PM on November 2, 2011

You can build your own micro version using a $24 controller board and $15 frame. You need to add a battery, motors and speed controllers -- there are suggestions for the appropriate ones on the pages I linked to. You'll also need a radio and receiver. This one is $23 and works great (I've got two).
posted by unSane at 3:48 PM on November 2, 2011

(Those things really are simple to fly, once you have gyros and an altimeter)
posted by unSane at 3:49 PM on November 2, 2011

and makes mounds and mounds of coleslaw.
posted by hal9k at 4:24 PM on November 2, 2011 [1 favorite]

If you crash a vehicle from a half-mile in the air it doesn't really matter if it chops you to bits on impact.
posted by LogicalDash at 4:30 PM on November 2, 2011

I've seen these things (unmanned!) with deployable parachutes FWIW
posted by unSane at 4:43 PM on November 2, 2011

From the site:

Should anything go wrong, e-volo can still safely land even if up to four of its sixteen motors should fail. Flight time can last between ten to thirty minutes, depending on the payload and the capacity of the lithium batteries. With an empty weight at 80 kg (including batteries), e-volo fits into the class of ultralights. [...] With a current flight time of on average 20 minutes, future versions promise anywhere from an hour or more. A hybrid drive, in which a conventional internal combustion engine generates the necessary electrical power, would already show an hour-long flight time.

posted by vanar sena at 4:49 PM on November 2, 2011

First manned electric multicopter maybe, but not the first
posted by jpdoane at 4:50 PM on November 2, 2011

I wonder why they didn't go for a ducted fan design? Simpler/lower weight? I would have thought that ducting would improve both efficiency and safety.
posted by vanar sena at 4:53 PM on November 2, 2011

EDF designs are generally not as efficient for these kinds of small prop applications. I think one of the problems is that the RPMs get so high that the blade tips start to approach mach speeds which gets nasty. I have a small non EDF plane with a very high KV motor and I can hear it start to rip up the air when the RPMs get up there. Generally multicopter designs use slow-fly props because the blades of the props suffer less from the wake of the other prop at lower RPMs.
posted by unSane at 4:58 PM on November 2, 2011

On the safety aspect, these designs typically use a single battery which feeds an ESC (speed controller) attached to each motor. The motors and ESCs are the chief point of failure but you are relying very heavily on a single power source. The flight controller board may or may not run off the same power source: it's generally safer if it has its own 5v power supply but if the main power fails all bets are off.
posted by unSane at 5:02 PM on November 2, 2011

As I understand it, helicopters are limited by (vehicle forward velocity + blade tip linear velocity at forward approach) <= mach 1. Ducted fans should allow smaller blades, right? So that should reduce blade tip speed at the same RPM. What am I missing?
posted by vanar sena at 5:05 PM on November 2, 2011

(sorry if I'm asking stupid questions btw)
posted by vanar sena at 5:06 PM on November 2, 2011

There has been some discussion of it but I think the conclusion was the EDFs are built for speed rather than static thrust (=small prop, high pitch), whereas static thrust (=big prop, low pitch) is what's required here.
posted by unSane at 5:08 PM on November 2, 2011

Full physics of why EDFs aren't good for this outlined here.
posted by unSane at 5:09 PM on November 2, 2011

Thanks for the link. I still don't completely understand (given a fixed blade size and RPM, shouldn't simple ducting improve thrust?) but I'll go do my own homework.
posted by vanar sena at 5:17 PM on November 2, 2011

The question is whether it improves the thrust enough to compensate for the weight of the ductiing etc, I guess.
posted by unSane at 5:22 PM on November 2, 2011

Yeah that's what I'm suspecting too. Since they're going to depend on vectoring to drive the thing, I assume they might add a few ducts down the track. The design page shows some sort of frame that resembles shallow ducts but I could be wrong.
posted by vanar sena at 5:31 PM on November 2, 2011

did anyone else notice that it looks like each motor is being held on with pop rivets? pop rivets? really? I think I'd like something a bit less emotional in terms of sheer strength.
posted by lomcovak at 5:33 PM on November 2, 2011

I don't believe they use vectoring. It's simple differential thrust to tilt the frame in the direction you want it to go, plus an altimeter to maintain horizontal flight.
posted by unSane at 5:35 PM on November 2, 2011

There's another open source ardurino based quad out there

The Arducopter

We have one here at work, I've been flying the past couple of days. Prolly going to get one at home so I can hack on the firmware.

I want to be the dude flying that thing so bad, but I so don't want one of those brushless devils biting into my thigh.
posted by The Power Nap at 5:38 PM on November 2, 2011

Wasn't there an issue where the model-sized equivalents of these sometimes just freak the heck out and fall out of the sky? Possibly even a metafilter post about it?
posted by Dr.Enormous at 6:09 PM on November 2, 2011

Looks like the Mythbusters may have to revisit another myth.
posted by chemoboy at 6:16 PM on November 2, 2011

The Starcraft Terran-music sounding soundtrack goes with the Starcraft looking vehicle.
posted by Dia Nomou Nomo Apethanon at 6:18 PM on November 2, 2011

Any idea why the pilot is sitting on top instead of suspended underneath?
posted by dontoine at 7:16 PM on November 2, 2011

Probably just easier to build that way. It's way easier to put a chair on a platform than suspend it below. Also the motors and electronics are much easier to get at if they're low. Most of the model versions use suspended payloads (typically cameras).
posted by unSane at 7:23 PM on November 2, 2011

I look at this and all I can think is that somewhere in Texas a sheriff's deputy is watching this and is about the get an unplanned vasectomy.
posted by Kid Charlemagne at 7:32 PM on November 2, 2011

Amazing how all the whirling blades were precisely at nut level.
posted by bonobothegreat at 8:06 PM on November 2, 2011

It looks like if he were to fall back he'd be headless.
The whole thing looks like an evil genius James Bond torture device.
"Tell us the secret and we'll let you down before the battery runs out." or "We'll toss cats at you"
posted by cccorlew at 8:17 PM on November 2, 2011

I was oddly reminded of the Wright Brothers' first flight when I watched this.
posted by unSane at 8:35 PM on November 2, 2011

unSane: I was oddly reminded of the Wright Brothers' first flight when I watched this.

Was it the entrepreneurial spirit? The potential dawn of a new age in flight? Or the uncomfortable proximity of spinning blades.
posted by Popular Ethics at 9:07 PM on November 2, 2011 [1 favorite]

It doesn't really look all that stable. I'd be surprised if he could get it more than 10 or 20 feet off the ground and still be able to control it. Reminds me of some of the Avrocar test flight videos from the 50's/60's.
posted by crunchland at 9:37 PM on November 2, 2011

Crunchland, he's not really controlling the stability aspect. It has an arduino board which uses accelerometers and (I would imagine) an altimeter to detect the attitudde, position and motion of the aircraft and calculates inputs to the motors to keep it stable. These things, properly programmed, are rock solid. The pilot is not in charge of keeping the thing attitudinally stable like they would be in a helicopter. He should be able to fly it hands off, or simply increase throttle to rise or reduce throttle to descend.

The main challenges to stability come when the attitude of the aircraft is changing faster than the controller board can compensate for. At this point negative feedback (to keep it stable) can become postiive feedback (which makes it uncontrollably unstable). This is unlikely in a big craft like this. It tends to happen in small craft travelling at high speed.

For example, I have a plane which I use for shooting video and which is gyro-stabilized on two axes (pitch and roll). These gyros basically detect uncommanded movement and move the control surface in the opposite direction to neutralize it. When the plane is moving at normal speeds the gyros are incredibly effective -- I can fly it perfectly level in winds that would otherwise make it unflyable. However, if I put the plane into a steep dive, the gyros aren't fast enough to keep up, and it will go into uncontrollable oscillations. Luckily I have a kill switch for the gyros which returns it to normal control, for just these kinds of situations.
posted by unSane at 10:23 PM on November 2, 2011 [1 favorite]