Can't leave the ground.

Good day,Tried my first test flight today without success.My goal for today was to hover in stabilized mode perhaps move around a little.HT-FPV frame10-47 propsAPM 2.5 with GPS and sonar2.7.3DX825 amp plush ESCDid the setup and calibration during the week.Gently applied throttle and either the back or front would rise, one end on the ground. Definitely not level so I thought it was not balanced correctly. Added weight to either end but the same results. Either the front or back would lift off, then would attempt to flip before I cut the throttle. Actually flipped once.I'm missing something here.I also noticed a spike in the throttle on the bench and during my test flight. Brief increase in speed before retuning to normal. This happen consistently.Any suggestions?ThanksRandy

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  • I did see text files in the folder. I will have a look and upload them after work.

    The other files I was able to play back in MP. Not sure if it is a tool for troubleshooting or just viewing your flight. That is where I noticed it said "Alt-hold". Was in Stabilize then it switched but perhaps means nothing. 


  • I have uploaded a log file which I think I did on Sunday.

    Have a look. I think it is saying I'm in "alt-hold" instead of stabilize. I not sure how to interpret the logs. I did a flight test on Saturday but the dates and times don't really match.

    Is there a tutorial for using the flight logs?

    There is no KMZ or GPX file for that date. Not sure what the file extentions mean.




    2012-09-16 10-15-14.rlog

    2012-09-16 10-15-14.tlog

  • I have seen many videos where the quad takes off without any issues but I'm not working the controls so I agree I need experience.
    I will work with the controls on the DX8 to see f that helps.
    I'm not familiar with the logs so I'll research that so I can post.
    Raining here today so I will try during the week.

    The props are new, do I have to balance them?
  • @R
    Yes, I did buy the adapter board from James.
    The orientation is exactly the way you have it your post.
    The GPS points in the correct direction and it moves as I turn the quad.
    I did the motor test several times. Starts with motor one and goes clockwise.
    Motors all start at the same time and looks good, just the front or back rises first. Doesn't ascend evenly.
    Perhaps I have to adjust the trim at the transmitter?

    Should I expect the quad to ascend evenly as I apply throttle?
    What do you think?

    Thanks for your comments.
  • I have recallibrated the ESC and leveled and made sure it was on the X configuration.
    Made sure it was balanced.

    Still either the back or front rises first as I give it throttle.
    If I try and adjust the yaw when lifting off then it helps but I lose control immediately once in leaves the ground.(Yaw and throttle are on the same stick. I thought it would have been pitch for forward and back)

    Could my problem be the PID settings?

  • Thanks for the comments.
    I will go through the setup again. Perhaps I have over looked something.

    The DX8 is new.
    I will suspend it from string and make sure it is balanced but I agree that I don't think this is the current issue. In my hands I can feel the front and rear motors are not equal.
    I will check the soft start on the ESC.

    This is my first quad so I will go through the setup again but suggestions are always welcome.

  • If you have not already, remove the weight for balancing.. unless it is extremely out of balance. That is not the problem.

    But with a 'flying man' type frame, it will come into play once loaded up with the camera. How much? You are not there yet.

    Can you suspend the aircraft somewhere near the CG by a means that will not be fouled by the props? If so, you can determine if the controls are correct. When I started flying my 3DR based frame (home brew) Aruducotper, Elevator was reversed. Even in stabilzed mode it was evident.

    Is your DX8 new? Mine DX6i was used and had a glitchy Airleron pots. I could see it on the 'Monitor' setting. You might check the same thing on yours. It should also be evident in Mission Planner during radio calibration if such a thing exists on your system.

    Oh, I have to fly my AC in ACRO (fixed wing) mode on the DX6i  NOT Heli. Heli slaves Chan 5 with Throttle (inversely). Not sure about how the DX8 functions in Heli. You only want Throttle changing the ESC drive.

    Do your ESCs have a soft start function? They don't need that with a quad usually.

    Also try disabling/disconnectng the sonar input.. simplify the installation as much a possible.

    I used a servo tester to determine if the motor rotations were correct on my quad.

    Another idea is a short leash type of tether. Twine about 6 -8 inches in length connected one to each arm. The other end is secured to a large flat board or heavy items that the quad cannot possibly lift. This way you can get up off the ground but control how much it can 'get away'.

    Good Luck


  • Are your props spinning the right way?  Are they plugged into the correct channels as per the wiki?  Do the hand test!  Hold on tight and clear to the underbelly and apply throttle - you'll soon see where the drive isn't coming from.

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