Hello all,
Sadly I have a flip-crash today with my new-build copter. Big thanks if you could give me some tips on troubleshooting this issue. I am not sure if the crash was due to bad PID setting or due to faulty ESC.
It is a quadcopter using :
- TBS discovery quadcopter frame,
- TBS AerialMob arm,
- 15" prop,
- DYS 480kV motor,
- DYS ESC SimonK "tgy_debug" 2-5S max 30A,
- 4S 4000mAh battery,
- pixhawk,
- ArduCopter V3.2.1 Quad.
Following are some previous flights. 3) and 4) are crash-flights.
1) Completed an auto-tune. It was flying OK but flight time was only 10mins.
2) I then changed to 5S 4500mAh battery. All-up-weight was 2.1kg. Completed the auto-tune. Flight time increased to 17mins. Tested alt-hold and loiter mode. Both looked good. Hovering throttle was 400~500. Should have room to add a bigger battery.
3) I then increased to 5S 10000mAh battery. All-up-weight was 2.6kg. Took-off in alt-hold mode but the motor-sound was pulsing quickly (5~10Hz I guess). Started auto-tune. After auto-tune completed, the pulsing sound was still there. And suddenly the copter flip-crashed to the ground. One self-tightening propeller flew-off from its motor.
3.5) Fixed broken parts. Screws propellers directly onto motors. Used mission planner to reduced rate-roll-P/I/D to half. reduced rate-pitch-P/I/D to half. Reduced rate-throttle-P from 6 to 5. Prepare to re-do autoTune again.
4) Still using 5S 10000mAh battery. Took-off in stabilize mode. No pulsing sound from motors. Remained in stabilize mode and was able to hover it 2~3 meter above ground for 3~4mins. But then the copter flip-crash to the ground again. Right after the crash, 4 ESC were very hot. Battery temperate was normal. 4 motors were only a bit warm. Suspect ESC self-shutdown in mid-air due to overheat.
I try to study dataflash log for the 4) flight. I see RCOUT-Channel1 suddenly goes up to maximum. At the same time copter stars to roll without following the DesRoll. So can I say motor-1 (or ESC-1) is stopped in mid-air?
I certainly will replace all the ESC. But I am not sure why those ESC worked in the 2), but not in 3) and 4).
And is simonK ESC good or not? The AutoTune wiki page suggests simonK ESC is prone to sync issue. But isn't simonK ESC designed to prevent motor<->ESC unsync?
In 3) I was flying a 2.6kg copter, but the PID was auto-tune for a 2.1kg. Would this cause the problem?
Sorry for my lengthy post here. I tried to help myself and ask google first. But I seem not capable to fix my copter by my own .....
I attached dataflash log for 4) flight. Thanks a lot if you would take a look and help checking what went wrong.
Many many thanks~~~
Wilson
Replies
We just had a similar issue like this. Were you able to solve your problem? I believe we should be powering the servo rail using a BEC
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We had a recent crash of our Pixhawk quad in mid-air. It flew well for about 30 secs but then suddenly it looked like one of the ESCs or motors failed and the quad rolled over to the right. We are using Tiger Motor Air ESC 40A 600Hz No BEC 2-6s compatible with the Pixhawk and the T Motors 4006 380 kv motors.
The logs show NO brownout or software failure. CURRENT Vcc paramter shows a stable 5.1 volts in the log. Vibrations are also under the desired levels. Everything seems ok and then the sudden flip. These ESCs have a signal and a ground on the servo cable connector and we are plugging it directly into the motor outputs on the servo rail. Pixhawk has the latest stable firmware for the copter.
Could this be an ESC issue? Should we flash the BLHeli firmware on these stock ESCs.
The dataflash log is at: