Discussions

Hi everyone! I’m new in the forum and in the aeromodelling world.

I’m building a low cost quadcopter drone based on APM 2.6 for my university final project and I need some help with some issues I’ve experienced. First of all I’m gonna focus on the most disturbing one.

This week I performed the first test flights, flying only with Stabilized mode, ‘cause I haven’t calibrated the compass yet (this is one of the other issues I’m having, I cannot calibrate my compass).

Getting to the point, at my third test flight, one minute after take-off my drone suddenly dropped to the ground like a stone. Here you can watch a video of the accident:

https://www.youtube.com/watch?v=ctlrmx4Xghw

I still don’t know what happened. First I thought one motor had failed, for some of my bullet connectors are quite troublesome. Then, watching to the video, I got to the conclusion that if only one motor had failed, the vehicle wouldn’t have dropped this way, I think it would have started spinning or something, so my conclusion was that all the motors had stopped at once (when I picked it up from the ground, the LED’s of the APM were flashing as usual).

As you can see on the video, the accident occurred just after quite a long yaw to the left, so one hypothesis I worked out was that maybe the APM was Disarmed after 5 seconds of holding the throttle stick to the left, though that’s only supposed to happen when throttle is set to idle, not at the middle of the power range…

What do you think about the accident?

This is quite a disheartening situation, ‘cause now I cannot rely on my quadcopter until I have this issue solved. Who knows when it’s going to fail again? It’s too risky to fly it now.

By the way, it was not a low battery issue. The voltage at the moment of the crash was around 12V.

Here I attach a list of my main components:

Motors: HexTronik DT750 Brushless Outrunner 750kv

http://www.hobbyking.com/hobbyking/store/uh_viewitem.asp?idproduct=6247&aff=371472

ESC: Turnigy Plush 30amp Speed Controller

http://www.hobbyking.com/hobbyking/store/uh_viewitem.asp?idproduct=2164&aff=371472

APM 2.6: http://es.aliexpress.com/item/APM2-6-ArduPilot-UAV-Flight-Controller-APM-2-6-6M-GPS-w-Compass-Power-Module-915Mhz/2021736205.html

Battery: Turnigy 2200mAh 3S 25C Lipo Pack

http://www.hobbyking.com/hobbyking/store/uh_viewitem.asp?idproduct=8934&aff=371472

 Turnigy 9X 9Ch Transmitter

http://www.hobbyking.com/hobbyking/store/uh_viewitem.asp?idproduct=8992&aff=371472

Thanks!!