:sparta: Amazing and world leading feat, see it here: https://www.youtube.com/watch?v=VVBv22YKRiQ (https://www.youtube.com/watch?v=VVBv22YKRiQ)
Not that impressive really. Big batteries, big props and low kv motors all within LOS. Anyone of us could of done it.
Hardest part would of been getting the permissions
How comes James May's effort got banned then?
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Maybe because it was autonomous?
Maybe one of you fixed wing fpv guys should have a go that would be good.
Quote from: Brucey on February 27, 2016, 07:54:12 PM
Not that impressive really. Big batteries, big props and low kv motors all within LOS. Anyone of us could of done it.
Hardest part would of been getting the permissions
This is it, I mean if you think about it, a Phantom 3 gets 20 minutes flight time. So it's only three batteries for a phantom.
This really isn't a 'feat' at all, especially with a chase boat.... I could reel of a list of people from this group that could have easily done this, myself included....
Ah well, I guess the difference here is they 'did' do it....
Keukpa
Quote from: BillM on February 27, 2016, 07:42:12 PM
:sparta: Amazing and world leading feat, see it here: https://www.youtube.com/watch?v=VVBv22YKRiQ (https://www.youtube.com/watch?v=VVBv22YKRiQ)
Should have just added the video link to the existing thread on this flight.
http://www.fpvhub.com/index.php/topic,48379.0.html (http://www.fpvhub.com/index.php/topic,48379.0.html)
Lol, maybe if you think that you could do better, go for it. This can be beaten with fpv on multirotor (x4). This is an accomplishment for multirotor, so do not get confused otherwise.
Well, this guy did better 9 months ago:
| | | | | ! No longer available (http://www.youtube.com/watch?v=BeThBC1nARc) | |
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54km, 61mins flight time. So not only did he travel much further, he did it quicker and with a mix of head and tailwinds.
He did 3km out and back multiple times, that's the only difference. |
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Quote from: BillM on February 28, 2016, 12:41:11 AM
Lol, maybe if you think that you could do better, go for it. This can be beaten with fpv on multirotor (x4). This is an accomplishment for multirotor, so do not get confused otherwise.
As Steve W points out.... not really.... it 'would' have been cool if they didn't use a chase boat! Don't get me wrong....it's cool... but not quite 'aviation history' ;)
Keukpa
Ok, so it is a record with a chase boat if you like, has anyone got more motivation to do better or exceed?
Quote from: Steve W on February 28, 2016, 01:02:53 AM
Well, this guy did better 9 months ago:
| | | | | ! No longer available (http://www.youtube.com/watch?v=BeThBC1nARc) | |
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54km, 61mins flight time. So not only did he travel much further, he did it quicker and with a mix of head and tailwinds.
He did 3km out and back multiple times, that's the only difference. |
|
Any idea what the above setup is?
You lot are a tough crowd! Give the guy a break!
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Quote from: Dragon Lady on February 28, 2016, 11:16:26 PM
Any idea what the above setup is?
According to the video description:
Config:
AUW 2800 gr
NAZA-M V2, OSD TBS Core Pro
EzUHF, TBS69, etc, etc
Quote from: elmattbo on February 29, 2016, 12:18:15 AM
You lot are a tough crowd! Give the guy a break!
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"Amazing and world leading feat"
Not that amazing, and the only thing he leads is doing it over the Channel.
I am the first person to fly over my field, should I contact Guinness World Records?
Theoretical question:
As a multi does not generate extra-to-props lift in motion [?], would a multi stay in the air the same amount of time - regardless of whether travelling forward Or just hovering ??
If the same, than you could beat this record - without using a chase boat - by just sitting on a beach, whilst the multi hovers over the nearby sea - record of longest flight time 'over the sea' ??
:laugh:
Quote from: wgt40w on February 29, 2016, 01:10:01 PM
Theoretical question:
As a multi does not generate extra-to-props lift in motion [?], would a multi stay in the air the same amount of time - regardless of whether travelling forward Or just hovering ??
If the same, than you could beat this record - without using a chase boat - by just sitting on a beach, whilst the multi hovers over the nearby sea - record of longest flight time 'over the sea' ??
:laugh:
Let us assume still air as a reference.
If the multicopter was simply hovering the only power required is to maintain position.
However if the multicopter was moving, power would be required to overcome the drag induced over the frame as well as the simple wind resistance. In addition I doubt very much if the shape of the frame moving through the air would generate any lift to reduce the load on the thrust borne lift of the motors and props. Therefore I would estimate that it would stay in the air for less time when moving.
Quote from: electrotor on February 29, 2016, 02:02:28 PM
Let us assume still air as a reference.
If the multicopter was simply hovering the only power required is to maintain position.
However if the multicopter was moving, power would be required to overcome the drag induced over the frame as well as the simple wind resistance.
I would estimate that it would stay in the air for less time.
but there is transational lift. like a helicopter rotor, the disk moving through the air generates lift.
so Quads tend to be more efficient when flying forwards or in fact in any direction. obviously the efficiency reduces as the disk tilts forward so it could be negated in fast forward flight but if you are at less than 15 degrees angle of attack relative to the oncoming airflow then you will see lift.
/Steve
I've noticed I can fly forwards straight and level with my quad at a lower throttle setting than just hovering so you're probably right stevec
Quote from: stevec on February 29, 2016, 02:05:38 PM
but there is transational lift. like a helicopter rotor, the disk moving through the air generates lift.
so Quads tend to be more efficient when flying forwards or in fact in any direction. obviously the efficiency reduces as the disk tilts forward so it could be negated in fast forward flight but if you are at less than 15 degrees angle of attack relative to the oncoming airflow then you will see lift.
/Steve
A helicopter rotor is not simply a propeller pointed up the way. The pitch angle of the blades varies throughout each revolution, at least in a helicopter with a swash plate. This pitch change along with the fact that in forward flight a blade will also be retreating during a rotation causes dyssmetry of lift. Certainly there is an effect caused by translational lift but I wonder if the other negatives would cancel this out. It has maybe never been tested. Any takers?
Quote from: Steve W on February 29, 2016, 02:09:53 PM
I've noticed I can fly forwards straight and level with my quad at a lower throttle setting than just hovering so you're probably right stevec
I have noticed reduced flight times on windy days so perhaps there is sweet spot where low-ish airspeed helps generate a little extra lift but in higher winds (and therefore higher airspeeds) the drag and wind resistance takes more power to overcome than the reduction of power gained due to the extra lift generated.
I suppose it is difficult to know for sure without testing.
Quote from: electrotor on February 29, 2016, 02:16:40 PM
A helicopter rotor is not simply a propeller pointed up the way. The pitch angle of the blades varies throughout each revolution, at least in a helicopter with a swash plate. This pitch change along with the fact that in forward flight a blade will also be retreating during a rotation causes dyssmetry of lift. Certainly there is an effect caused by translational lift but I wonder if the other negatives would cancel this out. It has maybe never been tested. Any takers?
There are a lot of anecdotal references but I have not seen any proper proof.
I have noticed (like Steve above) that when flying forwards I tend to need to take a bit of throttle out or it climbs.
it would be nice to see if a proper teetering head design made things any different but I doubt it would add anything except complexity.
I think that if you want efficiency you use wings, if you need the adaptability of landing anywhere then either land the plane on its tail google style or get a multi and live with the short range.
/Steve
So - to go back to my original question:-
To beat the Cross Channel record, I could sit on the beach,say, on the East coast and either hover over the sea or fly in circles over the sea (establishing which is the most efficient energy usage method) and claim a new record !!!!
I wouldn't really bother - it would be as exciting as watching paint dry !!
Quote from: wgt40w on February 29, 2016, 03:15:00 PM
I wouldn't really bother - it would be as exciting as watching paint dry !!
A bit like watching their channel crossing video. ;D
Quote from: wgt40w on February 29, 2016, 03:15:00 PM
So - to go back to my original question:-
To beat the Cross Channel record, I could sit on the beach,say, on the East coast and either hover over the sea or fly in circles over the sea (establishing which is the most efficient energy usage method) and claim a new record !!!!
I wouldn't really bother - it would be as exciting as watching paint dry !!
Your mission wgt40w should you decide to accept it, is to do just as you suggest. In order for your possible record to be accepted you will require a team of observers from Guinness World Records and some method of keeping everyone awake. Hey, maybe that's why they had the chase boat after all - boredom alleviation.
Quote from: Ratty on February 29, 2016, 03:46:45 PM
A bit like watching their channel crossing video. ;D
Yeah, only slower!
Quote from: electrotor on February 29, 2016, 03:50:56 PM
Your mission wgt40w should you decide to accept it,
No thanks, I'll leave it to Com Truise as the theme for his next film !
Perhaps you could tow a rubber dinghy across the channel with an s900 or maybe wake board behind it
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Now that would be worth watching :D
Maybe I was too harsh on the guy - it is an achievement after all.
It's just that when I was watching the video I wanted to slap him because he made it sound like it was a huge technical achievement when it really wasn't. Certainly with a couple of hours thought any of us could do the same. Maybe a couple of extra hours for me, but I'd get there eventually :laugh:
What he should be congratulated on is actually getting off his backside and doing it - he is indeed the first person to fly a quadcopter across the channel, so fair play to him for that.
Next up:
- Non-stop return journey. That way it's a technical challenge because unless the winds are 0, there will be a headwind one way. (Do you need permission from France if you're not landing? Just buzz the beach and come home?)
- FPV version, no chase boat.
That is the hard part, permission, there are a few people on here who could do a round trip with a plane tomorrow but if you can't post the video then there is no point.
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Tech explanation http://www.copters.com/aero/translational.html (http://www.copters.com/aero/translational.html)
Back on Topic.... permission... Just do it, don't use your own yootoob account though ;D
and isn't this a double thread?
Quote from: Gundummy on February 29, 2016, 06:26:35 PM
Tech explanation http://www.copters.com/aero/translational.html (http://www.copters.com/aero/translational.html)
Back on Topic.... permission... Just do it, don't use your own yootoob account though ;D
and isn't this a double thread?
Whilst the principles are the same be it model or fullsize, the numbers and effects at various airspeeds cannot be read directly across. This is because of Reynolds Numbers (RN). In very crude terms, you can scale down the size of the aircraft but you cannot scale down the air in which it flies. Full size aircraft fly in a very wide band of RN but our models have a much narrower band.
Google RN and be prepared for brain cramp. ;D
electrotor :notworthy: ...
(Have you seen Antman?) ;)
Quote from: Gundummy on February 29, 2016, 08:05:26 PM
electrotor :notworthy: ...
(Have you seen Antman?) ;)
No, but I've read Michael Crichton's book Micro.