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elev-8 rotates (yaws) on ground, then flips — Parallax Forums

elev-8 rotates (yaws) on ground, then flips

stanles78stanles78 Posts: 8
edited 2014-11-17 18:33 in Robotics
My elev-8 quad spins(yaws) when under part (less than half throttle) no concrete surface. As soon as throttle is increased to take off, the quad flips. I have checked every motor direction and verified the prop placement and tripled checked the servo leads. I think one of the motors is spinning at a different speed thatn the others, creating a differential torque. Any help would be really appreciated.

Comments

  • PublisonPublison Posts: 12,366
    edited 2014-11-06 13:03
    Welcome to the forums!

    First question, is this an ELEV8 version 1 or 2?

    Have you done the ESC Calibaration? That is Max Throttle and Min Throttle Calibration ?
  • PublisonPublison Posts: 12,366
    edited 2014-11-06 13:10
    Also, it would be good to know which transmitter you are using, and how you have it set up.

    I have to log off for the night, but will check back in the morning.
  • stanles78stanles78 Posts: 8
    edited 2014-11-06 13:17
    It is a Elev-8 version 1 and I am using a spektrum dx6i. We have been testing the controls with the quad strapped down and they all seem backwards. The front arrow on the Hoverfly board points to the front of the quad (between the black checked arms). There is another elev8 here from a previous group that has the hoverfly board pointing between the red arms. i have not inspected the wiring on the other one to check if they just put the decals on differently or if there is something else.
  • stanles78stanles78 Posts: 8
    edited 2014-11-06 13:20
    The ESCs were programmed with the card and calibrated with the throttle up, 2 beeps, throttle down, three beeps procedure. The gear channel is set to up25% and down25%. The other EPAs are 100%
  • PublisonPublison Posts: 12,366
    edited 2014-11-06 13:45
    It is possible that the incorrect props(CW vs CCW) got put on the motors. I would double check that first.
  • stanles78stanles78 Posts: 8
    edited 2014-11-06 18:27
    Nope. they're correct. I am using both the manuals that parallax provides and the build your own quadcopter book from Donald Norris, which is available from the Parallax website. Occasionally they differ slightly. I have been through all the forums and websites reading about they rotation and wiring, and I just cant find any issues with that. The fact that the quadcopter spins when there is still friction between it and the concrete is disturbing me, since that friction will go away once it lifts of and would then yaw even faster. We can get it yaw 360 degrees in probably 3 to 5seconds when it is still in contatct with the ground by just increasing throttle and not touching anything else. not enough trim to get rid of it.
  • Ken GraceyKen Gracey Posts: 7,400
    edited 2014-11-06 21:02
    Hmm. You shouldn't need to adjust any trims. Can you check all the following for me:

    - correct rotation direction
    - correct CW/CCW propellers installed in a way they provide lift when they're rotating the right direction
    - post a picture here on the forums so we can look at the propeller orientation
    - double check your ESC wiring to the OPEN board (I know you've done this, but please check it again - I've seen this problem many times)
    - confirm that you configured the board with the Hoverfly firmware update as an "X" configuration

    After you reply to these points, I'll give some thought to the next step of troubleshooting.

    Hang in there - we'll get you in the air and keep you there.

    Ken Gracey
  • stanles78stanles78 Posts: 8
    edited 2014-11-17 18:33
    A friend/coworker/instructor went through it and essentially redid all the wiring and programming. Flying now with lots fewer broken props but more broken landing gear. tennis balls make bouncy and super tough landing gear.
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