Hello,
I bought this copter from a fellow last year, but have only had a chance to fly it less than a dozen times. I am completely new to this, so it has been a steep learning curve. I am worried that autopilot has had issues since I got it, but I was too unfamiliar to realize it. I had two flight this last weekend, one in an auditorium to play with the basic tuning to see if I can fix the stabilize mode. The second was outside, testing if the compass calibration helped. At the end of the second (about 15 minutes of flying) the copter crashed. This is the second time I've crashed it. The first time a prop flew off because I hadn't noticed damage done to the root of the blade. This time it crashed in much the same way, as if it lost power to a motor, the one side dropped and it flipped to the earth.
In stabilize mode it has a wondering roll and pitch control which doesn't make sense anymore. I always attributed it to this or that (trying to read a lot) but I am wondering if the autopilot is broken in some way. After I had done a compass calibration yesterday, it was better. Sometimes it would hold level without touching the pitch/roll, and sometimes I would need quite a lot of input to keep it level, and other times I would need to put input in the other direction.
Anyway. I have no confidence in this anymore and hope that someone could tell me what's going on. I've attached the first log of the weekend where it was behaving very badly, and I've attached the second log where it was behaving better, but crashed at the end. Any help would be wonderfully appreciated.
Arducopter 3.2
Pixhawk, 3DR
F750 frame
16" props
5S 5A 25-50C nano-tech battery
no GPS hooked up
Please let me know what other information is needed. Thanks
Replies
You have several problems and I suggest you go back through the entire quad setup and calibrations.
Do a lot of reading so you understand all of this. Look hard at the First Time Setup
http://copter.ardupilot.com/wiki/introduction/
You have compass problems (location or calibration), high vibrations (bad props or PH mounting), accelerometer issues (is it correctly calibrated?).
Set logging to almost everything.
Don't fly until you sort through most of these issues.
Ahh, thank you. It's nice knowing for sure, instead of just guessing.
I was wrongfully sent a NEO 6 GPS with the machine, which I don't believe has an external GPS with it. A LEA 6 with compass is on it's way, will this help the compass issue?
The props are causing an issue for sure as a couple of the tips dug in in the first flight, but I thought I could get away with still using them. I will replace those.
The Pixhawk is mounted on a velcro pad. Should it be better tied down (I've wondered if the velcro is too unstable and foam tape would be better) or is that usually sufficient?
I tried calibrating the accelerometers before the weekend. It took 3 tries for it to accept the calibration, otherwise it would report bad accel. health I think. Is this somewhat normal?
I'll look up how to increase the logging.
Thank you very much for looking into it!
A NEO 6 GPS is an external GPS: the PH does not have an internal GPS . It may not have a compass?
Don't think velcro is a good way to mount a PH. Most use the 3DR foam pads. It should not be "tied down" that will only make it worse by transmitting more vibration. Search for threads on PH vibration or mounting:
Read this as a start: http://copter.ardupilot.com/wiki/vibration-damping/
Accelerometer calibration is done different ways by different people it can seem more difficult than it is. The most important step is the first where it says to start with the quad level. Take that literally, get a level and prop it up where ever required to have it level on both axis before hitting a key.
Keep searching a reading, also search YouTube there are some really great videos there.
Ooops, I meant external compass, not GPS...
Thanks a lot for the tips and suggestions. Much appreciated.