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P3P shakes while coming down

Discussion in 'Pro/Adv Discussion' started by SangYuP, Jun 12, 2016.

  1. SangYuP

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    Hey all, I have a P3P that flies smooth while gaining altitude or flying side to side. The only time I see it not smooth is when I'm decreasing altitude at full speed. As it's coming down I see it shaking while it's coming down. Is that normal? Thanks in advance.
     
  2. Oso

    Oso

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    It's not unusual if you are coming straight down at full speed. Is that what you're doing?
     
  3. Andrea

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    hmm... search the forum for "vortex ring".
    I am not exactly a copter expert, but I have the feeling that in there you could find the answer.
     
  4. alokbhargava

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    Does your video too shake? If it's not then it's acceptable. Secondly I never take it directly down unless it's about 10' high. I prefer move forward with throttle down. It comes down smoothly and video quality is excellent
     
  5. mindtrick

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    The area, from which I fly, requires me to come straight down when landing. My P3P wobbles too, but the vide is rock solid. I believe this is probably the nature of this type of flight.


    Sent from my iPhone using PhantomPilots mobile app
     
  6. msinger

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    Coming straight down is perfectly fine. I don't recommend coming straight down at full speed though. Some people do it and claim it's safe to do, but I don't like to tempt fate. VRS is not a common occurrence with the P3. However, I would not totally write it off as being impossible if you're flying in just the right conditions -- especially if you see your Phantom wobbling (which is one of the signs of VRS).
     
  7. MasterBlaster

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    Same happens to me if I try to come straight down. To prevent it I try to fly tight corkscrews while coming own. You'd be surprised that you can corkscrew coming down in really tight spaces once you have practiced and have it down.
     
  8. msinger

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    Coming down half throttle works well for me.
     
  9. m0j0

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    I would not come straight down at max decent rate can put your bird in VRS. I always apply some direction when coming down at the max rate. Should fix your problem.


    Sent from my iPad using PhantomPilots mobile app
     
  10. SangYuP

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    Thank you for your answers. What does it mean when it goes into VRS?
     
  11. peter west nz

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    Vortex ring settling. Descending into the disturbed air from the props.
     
  12. Wibble

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    Are you using prop guards?
    I have found the P3 to be almost immune to VRS - the V2+ was always on the verge of it.
     
  13. Wibble

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    Vortex Ring State is the normal term I believe.
     
  14. Meta4

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    VRS was something that the P2 series would encounter at its original high descent rate.
    DJI designers prevented that by limiting the P2 to a snail's pace 2m/sec descent.
    On the P3, they set the motors at an angle rather than leaving them vertical.
    This allowed them to raise the descent speed 50% to 3 m/s and still avoid VRS.
    VRS is pretty well unknown for the P3.
    I've only seen one report that might (or might not) have been caused by VRS and that Phantom was handicapped by propguards.
     
  15. SangYuP

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    Thank you for the info. I'll make sure from now on to avoid going straight down and I do not use prop guards.
     
  16. peter west nz

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    yes, you are correct. I was thinking of helis, which suddenly lose height when they get into this state.
     
  17. Wibble

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    Yes same term same principal.