My hexa copter seems to want to crash. After being in the air for 10 to 45 seconds it randomly dives sideways and down into the ground. I have attached the logs when I most recently flew it in Stabilize mode.
In the logs there are no error messages or any performance flags. The only thing not 100% is the z Acceleration as it is a bit high (not sure how to dampen that out).
Tomorrow I will try with a different GPS/Mag sensor and a 2.6 board instead of the 2.5 that origonally came with it
My setup
3DR kit
Hexa flying in X setup (all 6 motors are the same and calibrated)
10 inch blades
4 cell 5000 mAh 14.8 v battery 35-70C Discharge
V2.5 Adruino board
running ArduCopter V3.0.1
I would be grateful for any ideas
Thanks
Replies
Well replacing the ESC helped by increasing the time in the air but in the end the same thing happened.
here's a question
Is it possible that my ESC are failing because they have a amp rating that is too low?
My battery is 4 cell 14.8V with 35-70C discharge
My ESCs are rated to 30 A with a burst of 35A for 10 secs
We are using 10" Propellers
The motor is AC2836-358, 880Kv
From the seller's web site
"designed for 12x45 Propellers
Motor features:
Tested thrust:
Wattage
Thrust
17.5W
230gr
70W
650gr
160W
1290gr
210W
1380gr
"
The only thing I can do is replace the motor.... any idea's?
I had a similar problem with my quad. would fly typically 3 minutes or less before the crash but sometimes 8-10 minutes. I suspected a motor or esc and pretty much did what you are doing. Then I found I could save money on props and other carbon fiber repairs by testing it on the ground :) so I just took the props off in the house and fired it up simulating flight by moving the sticks etc. Seemed to work ok so I left it about half throttle for a few more minutes and lo and behold one of the motors just stopped. so I swapped the esc to another motor on the quad and fired it up again. after several minutes that motor stopped so I knew it was the esc. I took a closer look at the esc for the motor that stopped and noticed a small burn mark. I swapped it out for a new esc and did a test run again. this time in the log I noticed that the curves were much smoother so I think that bad esc was messing with the log as well. I have been flying fine ever since with at least 50 flights.
ok Well decided to do one more crash (i mean test) before changing the ESC for more data.
This time I started in Stabilize until i got it into a hover then switch into alt hold. It held for a few seconds before crashing snapping off one of my legs.
Motor 4 again had problems before the crash as seen in the logs. Now to replace my helicopter leg, swap out the ESC and try agian.
The bill for replacement parts is growing so and help would be much appreciated.
2013-10-17 10-36 1.log
My understanding is that the EV or the event log does not state what flight mode you are in.
I think EV 15 means that auto mode can be used (ie you have armed it and raised the throttle beyond a particular threshold then EV 15 is written to the logs).
If I switch into auto mode the logs will have a different entry under "mode"
examples:
MODE, STABILIZE, 473
MODE, ALT_HOLD, 473
Since it is not possible to arm (according to the documentation) in auto mode I don't think this can be my problem.
now to try one last time then switch out motor 4's ESC and see if that fixes this weird issue.
Looks like you went into Auto Mode.
Under EV in your log it went....
10- Armed
15- Auto Armed
15- Auto Armed
16- Take Off
And you had no Waypoint Heights.
I can see your Altitude going up after the launch but no WPAlt ( Is meant to show target Altitude)
Maybe upload your Mission and check if you intended to be in Auto or Check your Flight Modes on the bench.
ok well I have now tried several new things.
-Changed out the adruino 2.5 board with a 2.6 board.
-Changed GPS to one with a mag sensor
-Replaced several motors and one ESC
-Re-calibrated ESCs, MAG, ACC
-Recorded "motors" in the logs.
The end of the attached log shows the motors working to keep the helicopter at a near stable hover (flying in stabilize mode). Then they fall to zero just before the log ends. This was a crash as something failed. One interesting thing in the log is that motor 4 seems to drop just before the others shut down.
Would this be a ESC problem? Motor over heating? Software bug?
Tomorrow I will switch out the ESC and try again. Then if it is still the same motor then I'll replace it and try again.
I'll check back here tomorrow before starting to see if anyone has any ideas as to my hexacopter woes. Otherwise I'll post again after I try these two things
cheers
2013-10-16 15-07 7.log