Hi. My EAST program is working on building an ArduCopter as our big project this year. We have the frame up, but now are starting to run into issues. I have all the battery connections hooked up well, the ESCs all connected properly, and the Futaba receiver wired up. Now, we come to the big problem. When we take it out to test fly, just trying to get a couple inches off the ground, the Arducopter flips. It did this on a table, in the hallway, and the grass. 

My teacher and I did ESC calibration several times, and I've have attempted to level out the frame. I'm fairly certain that it is leveled out well, so I don't feel like this is a problem.

This brings up the big issue though, which is why the thing keeps flipping. Can anyone provide any help on this. Some detailed instructions maybe?

Also, we are using a 6 cell Venom battery (http://www.amazon.com/Venom-5000mAh-22-2-LiPO-Battery/dp/B0027GEYSE) and a Venom OPR2 Charger. Now, the battery is only showing 5 cells when hooked to the charger. I read that if you set it to 6 cells and start the charge it'll eventually bring the charge up enough for the charger to learn that this is the problem with the battery. Then stop the charge and restart it. When I monitor the charge of each cell, I see the charge of the cell reading 0.00 go up to 1.13 then 1.58, and then the charger errors out. Does anybody know of anything we can do for this? 

Any help would be greatly appreciated. This late in the year our funds are a little low, so we'd like to get it in the air with the parts we have.

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  • The first file only consists of this:

    ArduCopter V3.1.2 (e2ed3dd1)
    Free RAM: 65535
    PX4

    The second file does not look any more promising, mainly due to file length.

    <gpx creator="Mission Planner 1.3.0 build 1.1.5224.30728" xmlns="http://www.topografix.com/GPX/1/1"><trk><trkseg /></trk></gpx>

    The log files are generated in the device each time the controller is turned on or reset. They will run/log continuously while power is applied or the processor is functioning and running the code.

    A flight of several minutes will have much more data.

    This assumes, of course, that the logs are being retained and were not lost as a result of the crash.

    -=Doug

  • No big secrets on researching the logs...

    1)Go HERE

    2) Drill down in the picture below...

    3701722372?profile=original

    3) READ and Practice

    4) Post the *.tlog files here or at the other more technical forum to get a group mind opinion.

    -=Doug

  • Wow, you are getting the full immersion experience now aren't you?

    Fly away and crash.. are you able to obtain the logs to post here for analysis?

    If not, it will just be a mystery.

    Yep, CF looks cool and has advantages but for a learning machine, it is overkill.

    Busts up just the same as plywood IMHO but, costs a lot more.

    When you start messing with modes other than 'Stabilized' many other variables are considered.

    The default values for some of those variables has been a problem on some releases of AC code.

    It takes some research to make sure you don't have a value that the copter wants to see when you enter a mode.

    That is why the logs are soooo important after a crash/failure to analyze what went wrong -- usually.

    -=Doug

    • I will need to do some research into how to obtain the logs. But I will definitely try my best. Would like to know what went wrong. 

      We are building a frame that is 1150mm from motor to motor, measured diagonally. We hope to get some good stability, and based upon my experience with the aforementioned 25lb weight, we plan to have it in the air again soon. 

      This time, with another frame on standby. :))

  • We can hope Chris updates this post but, I got a text message from him yesterday stating

    We just figured some stuff out and gotit (sic) flying  :) :)

    Seems there is nothing like a deadline to motivate people and focus energy.

    -=Doug

    • Hi. I know its been a while, but like you said, deadlines get you going.

      I have gotten the copter functioning by remote, completely, land function and all. The autopilot worked once, and then the next time I tried a flight, I armed and it took off toward the heavens. At ~150 feet it began a rapid descent in a very very linear fashion toward a group of ROTC kids. When it hit the ground, very little was remaining of our carbon fiber frame. $170 down the toilet. That was on 4/22. Working on building a new frame fromm scratch with aluminum rods. I did discover, quite by accident, that the copter at max thrust, will raise a 25 pound weight. That is good, but has some very scary thoughts running through my head..

  • Keep at it, unfortunately this is a hobby not for the impatient, read the wiki threads mentioned above (I'm doing the same right now after a new motor install). If you need RTF contact a local Ardu builder and see if they'll help you make that deadline. :)

  • It has been good to talk with you and I have some information regarding your LiPo battery condition. From THIS page...

    A 3.7 volt RC LiPo battery cell is 100% charged when it reaches 4.2 volts. Charging it past that will ruin the battery cell and possibly cause it to catch fire.

    If the one 3S battery measured 17 Volts, that puts you definitely in the overcharge range. A good multi-chemistry charger, correctly set up, would not have allowed this to happen. Your battery was overcharged at 17/3 = 5.67 volts per cell.

    I cannot honestly tell you what the condition of the battery is at this point. Placing it on a discharge cycle with the charger will tell you if the battery is wrecked and can be salvaged. Maybe you will be lucky, maybe not.

    Regardless, you are learning about the many aspects of this hobby and technology -- even if it has been an expensive lesson for everyone.

    Let's hope your partner gets the wiring diagram/schematic posted soon.

    -=Doug

  • Hate to revive this thread, but I need some help. The 3DR Tech help said (like what was mentioned before on here) that the Power Module couldnt handle the 6S battery we were using. Well we bought an AttoPilot 180A to eliminate that problem. i wired it up and used a series circuit adapter and 2 brand spanking new n the AttoPilot, we are only getting 1.47 volts out of the module and to the Ardupilot. How do we get the 5 volts back out of it.

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