Cinestar 8 Operators with DJI A2

Discussion in 'Cinestar 8' started by Graydon Tranquilla, Jun 23, 2014.

  1. Graydon Tranquilla

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    How are others doing with the DJI A2?

    Based on what I am experiencing I see no benefits to the concept of: 8° inversion and a 3° inclination on the motor arms. Here is my Cinestar 8 on test flight #5..... just a few days ago and have had multiple flights since:
     
  2. James Cole

    James Cole Member

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    Nice build, but isn't it a bit of overkill for a GoPro?;)
     
  3. Graydon Tranquilla

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    Yes it does look a bit odd with that tiny GoPro underneath! :cool:
    Adding a rugged 3 axis BGC system soon and eventually a Panasonic GH4 if all goes according to plan.
    Also getting rid of that open source 2 axis Martinez BGC for an Alexmos 3 Axis or better.
     
  4. kjetil tønnesen

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    hello
    what do you think off the dji A2 on your cinestar 8?
    i have one on mine to with 500 booms and tiger 4014 navigator motors and 14" props and it is wery unstable when i comes to wind!!
     
  5. Graydon Tranquilla

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    I have had only 8 flights to date c/w a very light payload, i.e., GoPro3+ Black and a small 3 axis BGC. I start small then move up later when to time is right! It is super stable but not yet flown in stronger winds. I use 15 x 5.5 cf props and same motors as well as the default Basic and Gains settings listed in the A2 manual for the S800 EVO.

    And I am using the 4014 - 11 i.e., 400 KV motors with 2 - 6S - 6000 mah batteries onboard.

    BTW - Have you applied the hotgun glue to hold in the Canbus connections as indicated in the diagram on page 12? Also the GPS module mounts straight forward.... no need to adjust for magnetic angle of declination relative to true north..... but a few laps around the block may be required for it to self-correct.
     
  6. Drew Kachurak

    Drew Kachurak Member

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    Graydon - How are things with the CS8 and A2 going? We're getting ready to build another system and considering the A2. Considering KDE for motors and ESCs w/ 16x5.4 CF props.
     
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  7. Graydon Tranquilla

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    I am up to flight # 14 or so and no significant issues to date...... super stable, easy to fly straight, holds altitude extremely well.
    However I still have not tested anything beyond Attitude and GPS flying modes......
    Have not yet tested RTH, POI, Home or Course lock or Manual. Just trying to complete some aerial video work before testing additional features.

    While it flys extremely well but I did notice that I need to land in Attitude mode.
    When I try to land in GPS mode, the motors continue to idle and sometimes 2 or 3 motors rev up for not particular reason and the rig tilts over...... As to root cause, I have no idea yet. ESC were very well calibrated including speed range etc.
     
  8. Ryan McCrae

    Ryan McCrae Member

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    I saw mention of landing in gps mode causing tip over in another thread. Some one said it was because the its trying to find its position, as if it was still flying.
     
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  9. Graydon Tranquilla

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    One would be inclined to think that in view of post landing behaviour. FC logic process is probably something like this:
    IF landing has occurred....... stop motors after 2 or 3 seconds.
    IF landing has NOT occurred...... relocate closer to target GPS position.

    I am thinking a slightly heavier payload might resolve this issue.... I am testing with only a GOPRO on a small BGC.....
    not much AUW for a Cinestar Octocopter.
     
  10. kjetil tønnesen

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    Hello
    i am not so happy with the a2 and how it react to little wind,the a2 is not smooth in wind ,it correct all the time so i am going to switch controller ,I have been flying multicopter in years and never had this problem before with the wind ,but when i use A2 i get the problem of shaking in the wind so the hole gimble is shaking:-( bad.
    I have never had any problem with the A2 system ,just that it is not so smooth like i want to,so i am going to stuck with mk and now i am trying the hoverflypro board,it is super smooth:)
     
  11. Graydon Tranquilla

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    Drew,
    Wishing you great success with your build. I have been fortunate to have calm flying conditions for many days now but can't determine if my rig bumps in the wind until there is some wind.
     
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  12. Graydon Tranquilla

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    I was able to fly in gusty wind conditions today. My only payload on the Cinestar 8 - 1100mm is a GoPro3+ and Simple BGC 3 axis 32bit. I could tell that it was gusty by watching the Multirotor bump around a bit in the wind. It flies a bit steadier than did my previous 800mm Hex with the WooKong M but I never flew a Mikrokopter so I can't compare.

    In any case te only issue now with the onboard video is that there is some horizontal vibration, i.e., the yaw axis. I attribute this to less than perfect tuning of the yaw axis but also the fact that the tripod landing gear has two legs facing the wind and only one leedside. A heavier camera might help as well as a larger torque yaw motor or yaw motor on a gear reduction belt to help add more torque for yaw.
     
  13. Graydon Tranquilla

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    kjetil tonnesen et al,

    Thought I should update you on the DJI A2 on my Cinestar 8.......... I flew it again in stronger wind and on the lee side of a line of trees to get some rough air...... dialed down the A2 Basic and Attitude gains..... the MR stopped bouncing around in the rough air and the aerial test video turned out very smooth. IMHO - the stability is available once one adjusts the gains to be a bit sluggish with respect to RC joystick input.
     
  14. kjetil tønnesen

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    hello
    ok do it get better to dial down the attitude gain to??
    what number do you have on basic and attitude?

    thanks for letting me now:)
     
  15. Graydon Tranquilla

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    I started with the S800 defaults for both Basic and Attitude gains, assigned a Futaba T8FG RD "volume" dial to both so I could adjust the FC gains remotely while flying. Use the defaults for flying in no wind.
    Then for windy conditions I turned gains down by about 25%. Both Basic and Attitude gains were the the same..... see image of defaults before I adjusted values down by 25%. Stick response is more than adequate for typical aerial video slow but sure MR movement.

    My MR loaded, i.e., c/w batteries camera and BGC system weighs about 20 lbs.
     

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  16. Albert Chang

    Albert Chang Member

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    my experience with A2 is while in a gusty wind, the futaba 14sg allow it to dial the sensitivity of the controller to deal with the wind...
    it started in zero and adjust accordingly. it takes a little try on error, but it's very obvious in the air...
     

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