Welcome to PhantomPilots.com

Sign up for a weekly email of the latest drone news & information

Fc40 wobbly drifted in gps

Discussion in 'Phantom FC40 Discussion' started by 30secs, Jul 14, 2015.

  1. 30secs

    Joined:
    Jun 12, 2015
    Messages:
    889
    Likes Received:
    113
    Hey all. I went this meeting for a flight everything was good. Then I decided to take some quick pics so I fired up the 40 again..

    As it was doing is boot I moved out a little too get the cables in. By the time it was done the green was flashing so I took it up. This time it was a little wobbly and after a minute it stayed to drift more than the usual foot. I let it hover to stabilize but it didn't help.. Winds carried it and it wasn't locked on altitude either. I switched to atti and brought it down.

    Can you guys chime in as to why it did that?
     
  2. Monte55

    Joined:
    Apr 26, 2014
    Messages:
    2,198
    Likes Received:
    517
    Location:
    Raymore Missouri
    When you power up the bird....have it level and don't move it around. I plug in my battery and don't touch it. After I get the proper lights, I push battery in and shut door. The gyro is trying to stabilize when starting. That may not be your problem, but it might be.
     
    IflyinWY likes this.
  3. IflyinWY

    Joined:
    Sep 12, 2014
    Messages:
    3,470
    Likes Received:
    939
    Location:
    Where the deer and the antelope play
    Gotta agree with Monte55.
    Whenever you mess with it while it's waking up, you are just asking for trouble.
    Are you sure you got the second set of 20 greens, or did you just see one set? Regardless, that would have just been the "Home Lock", and you would have locked on the sats as you flew.
     
  4. 30secs

    Joined:
    Jun 12, 2015
    Messages:
    889
    Likes Received:
    113
    Not sure on second lock but it was interesting to test it. I don't always have a level surface but I'll try to keep it steady as it boots.
     
  5. Monte55

    Joined:
    Apr 26, 2014
    Messages:
    2,198
    Likes Received:
    517
    Location:
    Raymore Missouri
    The problem with getting the second set of quick green flashes(Home lock) after takeoff is the home point will not be where you think it should be. Maybe it's over a house or between or above trees. So using Home lock or Return to home will not yield good results.
    Solution...take your time and get HL at Home unless you want to change it in the air to a different location. If you are short of time at the field, leave the house a minute earlier.
     
    IflyinWY likes this.
  6. IflyinWY

    Joined:
    Sep 12, 2014
    Messages:
    3,470
    Likes Received:
    939
    Location:
    Where the deer and the antelope play
    Funny and right on the money Monte55. :D
     
    Monte55 likes this.
  7. Monte55

    Joined:
    Apr 26, 2014
    Messages:
    2,198
    Likes Received:
    517
    Location:
    Raymore Missouri
    I always find it a bit funny how people driving behind you wanting to speed or people in line behind you are so **** impatient. I want to tell them.."If you would have got up 5 minutes earlier this morning, it wouldn't even be an issue".
     
    IflyinWY likes this.
  8. 30secs

    Joined:
    Jun 12, 2015
    Messages:
    889
    Likes Received:
    113
    So I took the quad to the beach this evening. I didn't move it as booting up. It was however seriously slanted. When it home locked I went full throttle up and away it went. Excellent flight. Very tight and solid. Pushed it hard and let go, full push phunnels, atti, even tested Rth switch which worked great and to my delight gave me full control when i switched back to GPS. Home and course lock was awesome too. So yea I guess it was moving the quad on boot. Slanted position didn't matter.

    I did notice towards the end when I pushed it it would blink red a couple of times then return to green. I guess the vintage drops considerably when pushed.
     
  9. IflyinWY

    Joined:
    Sep 12, 2014
    Messages:
    3,470
    Likes Received:
    939
    Location:
    Where the deer and the antelope play
    Nice report there 30secs.

    Motors don't like sand. You say beach, I see sand. I really like my 68 liter plastic tote. The Phantom stores well and secure with props on. The lid makes a great place for liftoff.

    I can get red lights flashing on most of my batteries, with my heavily loaded FC40, just by climbing at full power. The lower the "C" rating, the easier it is to do. The Multistar 4000, with it's 10 C discharge rating will give me red flashes whenever I am "Hot dogging" (flying aggressively). All I have to do is ease up a bit and it will catch up.
    I think most batteries with a discharge rate below 30 will give you the low voltage warning a bit early if you push them too hard.
     
  10. 30secs

    Joined:
    Jun 12, 2015
    Messages:
    889
    Likes Received:
    113
    Thanks. So do you keep the default voltage warning levels? And if so do you put the bird down when it starts to consistently flash red? And how many minutes is that usually before it auto lands?
     
  11. Monte55

    Joined:
    Apr 26, 2014
    Messages:
    2,198
    Likes Received:
    517
    Location:
    Raymore Missouri
    I always time my flights. I have a timer on my transmitter. I have a good idea of the flight time of the Phantom whether it is bare, carrying a camera and gimbal, or fpv equipment. When I think I an nearing the end of the flight for the weight of the quad, I will goose the throttle. If I see it start to blink red a bit, I start to bring it in. I also will have it close at that time. Soon after if still flying. it will steady red blink. I land immediately. Not sure how long after the red blinking it will go to failsafe. Never tried it but I'm sure it would be soon. No sense in pushing my luck. I have never had a failsafe or even used the RTH. I have never had a problem so I think I'll keep doing it this way.
     
  12. IflyinWY

    Joined:
    Sep 12, 2014
    Messages:
    3,470
    Likes Received:
    939
    Location:
    Where the deer and the antelope play
    Monte55 has a great way of ensuring long battery life and minimizing the chances of having the Phantom land due to low voltage.

    I do play with battery voltages in the NAZA assistant. I've set them way too low and flown for over 20 minutes using the Multistar 4000. Folks who know a lot more about batteries than I do, say not to do this because it shortens the life of the battery. Sometimes it may be worth it, so the bird makes it home instead of landing on the other side of the river, or in it.

    The only time I land the bird when the light starts flashing is when I am conditioning a new battery. In that case I will set the first level, no load to 11.9. Some of those smart battery folks say it's good to limit the first 10 uses to 50% drain.
    Most of the time there will be a few minutes flashing red before I land. With first and second levels set close together, this is not possible.

    I've seen as many as 6 minutes red flashing before auto land. Again, this is not recommended because of how low you will be draining the battery if you have changed the settings in the NAZA assistant.

    Your times and mine will vary due to aircraft weight, configuration, electrical load, and density altitude; to name a few of the factors.

    11.1 volts is as low as you ever want to drain the battery, according to the brainiacs. :D