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Vortex - caused by propeller protectors??

Discussion in 'Phantom 2 Vision + Discussion' started by johnbrowning, Aug 17, 2014.

  1. johnbrowning

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    This is a video of my buddy's P2V+, was hovering at about 400 feet, has on the propeller protectors, came straight down, and he said at about 50 feet he lost control, wouldn't respond to any input, you can see the result.

    I've come straight down before and full speed and haven't had this problem, and don't have the propeller protectors.

    What are your thoughts??

    http://youtu.be/ZfCuQMzX8ME (PS - skip to the 2 minute mark).

    John
     
  2. Morgon

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    Vortex Ring State

    Never come 'straight' down, as you're flying through the turbulent air the propellers are generating, killing your lift (and your craft).

    Some people claim that the protectors exacerbate the issue, but I don't have any personal experience with them yet; my P2V+ protectors don't get in til next week.
     
  3. skyhighdiver

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    Don't use them when they come in they are phantom killers. Have had phantom drop from a hover with them on no stick input
    Since there removal never had a problem agian
     
  4. planedr

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    And you're pretty much an idiot for having your face that close to the props. Have you not seen what they can do to flesh?http://www.liveleak.com/view?i=8d9_1407980380
     
  5. pilotbcm20

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    Had them on mine last week and same thing happened except it landed in a pond and sank 8 ft. Was about 40-50ft up in a hover getting ready to bring it in. Started to move the drone forward over the landing area and that's when it lost control wobbled and fell out of the sky. Terrifying sight especially when it hits the water.
     
  6. Morgon

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    Just out of curiosity, were only the prop guards installed, or did you also string up the safety cord?
     
  7. skyhighdiver

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    just the prop gaurds
    :(
     
  8. Morgon

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    Yeah, I am pretty sure I read somewhere (perhaps here) that the safety cord is a must when using the prop guards.
    I dunno, I'll try them out at low altitudes when I get them and decide then. I still pucker when I see the thing over 100 feet in the air. :)
     
  9. cmhorka

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    I'm no expert, but 'losing all control' doesn't sound like a prop wash problem to me. Even if you were caught in a vortex, I'd think aileron input would show some effect. I think I'd look at other possibilities. My $.02
     
  10. DBS

    DBS

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    There's two things happening in these situations that people don't separate in there discussions... VRS wobble can be easily flown out of if the Phantom is in stock condition... but with those prop guards on... A wobble is very different to recover from... it gets amplified greatly by increased mass acceleration out at the ends of the arms and even out past the ends of the arms... try holding a three pound weight out straight armed parallel with the ground... no big deal you can do it all day... now jump up and down and try to keep your arms parallel with the floor... gets much harder because the acceleration of the weight makes it much heavier to stop... This is doubled by the seesaw effect of the opposing arm moving upwards and trying to stop it's momentum as well... All this being done multiple times per second and a firmware correction is trying to stop the whole thing by using a correction that doesn't take into account the extra weight, inertia, momentum, whatever you wanna describe it as...

    Prop guards didn't do quite as bad on the earlier Phantoms because they flew at a lower take off weight in the first place... now the Vision Plus is the monster out there approaching the designs max take off weight with the larger battery and gimbal etc...

    This whole thing is exacerbated by a slew of youtube videos released early by people trying to take your money or "reviewing" a set that was sent to them for free so they are being overly optimistic about results ...

    New pilots get entirely the wrong idea... they think it's safer to practice in a familiar area (back yard usually) where there are obstacles and obstructions and possibly people around to watch this new toy being flown... "keep it low" they are thinking... "it'll be safer"... totally backwards way of thinking

    The right idea is to get out in the open... get away from stuff period... if you got trees around then climb 60 ft above them ... it's like practicing driving when you're a teenager out in an open parking lot somewhere, but now you have to think 3 dimensionally... clear on all sides , above , and below... THAT'S when you'll stop wrecking and crashing your Phantom... When you have the ROOM to make mistakes and stop relying on cheap aftermarket plastic parts to makeup for poor choice of flight location :ugeek:
     
  11. CarlJ

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    I have a FC40 and have flown many times with and without prop guards. The truth is coming down from altitude is a little trickier with the prop guards on, but the difference isn't huge, and you certainly don't lose control unless your decent is like a bat out of hell.

    As others have pointed out VRS has a wobble associated with it, if it falls out of the sky like a rock it's not VRS.
     
  12. Werz

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    That has been my experience, too. It's been a while since I had the prop guards on, but they never presented a problem. Prop guards or not, I do not do direct vertical descents.

    I also watched the video. There was something rather predictable about that crash from the very beginning. And it wasn't the prop guards.
     
  13. Fplvert

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  14. Panamon Creel

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    The wobble is because of the loss of lift and the unit will lose altitude very quickly if it can't power out of it. Overall weight has a very big influence on the severity of the wobble, the more weight the worse it gets because there might not be enough max. trust available to pull out of it. With that in mind the P2V+ is heavier than the FC40 thus can't be directly compared. Operational altitude also has a big influence because the higher you go the less max trust is available to pull out of the VRS state ( or any other problem ).
     
  15. johnbrowning

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    Yes, too funny, my friend can be a knucklehead, in a good way. I wasn't there to see it. He bought the prop guards because his first phantom hit a tree. (Back to earlier post about higher = safer.)

    But, I do believe him when he said he came straight down from hovering.

    I came straight down from hovering my first outing with my P2V+ and didn't have any problems. That was before i knew of these forums and before I knew better, and now I don't come straight down.

    John
     
  16. MapMaker53

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    Doesn't RTH cause it to come straight down from 20 meters after reaching the home point?
     
  17. Phantom_Menace66

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    Ok first of all, as others have stated that was REALLY STUPID having spinning props so close to your face. You risked serious injury when it would have taken all of 30sec to shut down the motors, insert the card & get it back in the air. Secondly you need to understand about VRS (vortex ring state) which is turbulence created by the props, there are many threads relating to it on here & many helpful videos on YT. I knew nothing of it when I bought my first Phantom even after many years of flying fixed wing r/c aircraft and found the experience/advice of other Phantom pilots very helpful.
    Lastly, please don't refer to them as DRONES because people immediately relate it to high tech military and spying drones....
    Use common sense and think safety. If not for yourself, then other curious onlookers...
     
  18. MapMaker53

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    I've been flying my drone with the prop guards with no noticeable difference. I've even descended at a rapid rate from about 300ft without anything bad happening - which I will now rethink based on the vortex discussion here. But I would also add an additional possible cause of the rapid descent failures while prop guards are in place. The guards are fairly flexible with a concave shape underside that can easily catch air and be bent upward enough to possibly interfere with and slow down one or more props during rapid descent. At some points, the props are only 0.25 inches above the guards at rest. The string "bracing" doesn't make them much stiffer, if at all. Just discovering this convinces me to take it easy on future descents.
     
  19. SpikeFinch

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    Or for anyone that has a hard time understanding what is going on with the air...
    [youtube]https://www.youtube.com/watch?v=0z_hFZx7qvE[/youtube]

    The fact that there are 4 props on these things and can still stay in the air.. If you saw the air wash from these things you would just be in awe.... :eek:
     
  20. Clipper707

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    So in the end, did the Prop Guards actually protect the propellers?