Hello DiyDrones community!
I crashed my quad for the first time today and I cannot figure out why? Also, this is my first post, but I have been a long time lurker reading most of the multicopter threads to learn from other's mistakes and just want to say thanks to everyone involved with this awesome project. Now to the crash...
First off, I have had around 20-30 successful flights on my stock 3DR quad including in most all of the modes so I am confident all the hardware is setup correctly. Today while flying the angle the quad considers level seemed to rapidly drift from level to past 60 degrees pitch down resulting in the quad pretty much being uncontrollable leading to the crash. The best way I can think to describe what happened is by using the log and the video together. Most of the "unstable" look on the video is me at the controls trying to figure out what is going on.
Details: APM2.5 on stock 3DR quad (built from kit)
Video: 0:08 Log:~1000
Normal takeoff and quad is flying fine.
Video: 0:27 Log:~1500
While flying I noticed I was needing quite a bit of pitch up, but it was pretty windy so at the time I attributed it to the wind. After turning the quad about 90 degrees to the left is when I notice something is very wrong.
Video: 0:35 Log:~1730
The quad is pitched down causing it to accelerate forward even the log shows that it should be level. Continues to pitch further and further forward. Shortly after I pretty much lose control, but am able to barely recover and at the time I did not really have a clue what was going on. The quad continues to pitch forward as it flies to the other side of the field.
Video: 0:57 Log:~2320
I have full deflection on the transmitter to pitch the quad up. According to the log the quad thinks it is pitching up, but the video shows it still pitching forward.
Video: 1:00 Log:~2400
I did make a few adjustments on my radio earlier so just in case it was the radio I thought I would try RTL mode, but that just caused the quad-copter to pitch violently down even though in the log it shows the quad returning to level.
At this point the quad was flying very fast away from me and towards a building, so I cut the throttle and a small tree broke the fall.
I know serious vibration can cause the sensors to drift uncontrollably, but since I have flown the quad with no issues so many times I have a hard time blaming this. Furthermore I looked at accel vibrations just a few days ago and it was well within the +-3 that the manual suggests. I also make it a point to check all the screws before flying so I am pretty sure nothing came loose in flight.
Any ideas on what went wrong on this flight???
Thanks,
Brian P.
Video: https://www.youtube.com/watch?v=XBJuHiUTPrY&feature=youtu.be
Pitch in vs Pitch
Log is attached!
Replies
I have tried to see if I can recreate the problem by purposely causing the quad to vibrate (without props) and see if the level position drifts as it did in the flight, but the level position always remains level. As soon as I get a new prop all the damage from the crash will be fixed, but I am reluctant to put it in the air again until I know why it crashed in the first place.
Anybody have any trouble shooting suggestions or any possible reason why this happened? Thanks!!
Hrm, I see nothing unsual about the logs, but I'm not an expert either. I do notice that you switch to RTL and then back to Stabilize right at the end, not sure if that was intentional or not.
Added the Video