Quad doing unexpected flips

Log Analysis -- deprecated Copter Logs -- deprecated
1

quad is a f450 type
Mystery 12a esc’s
Turnigy D2822/17 motors
APM 2.6 with ublox gps and compass combined
Firmware is 3.1.5

I have been having trouble with my quad flipping for no apparent reason. On this flight I flew for about 5 minutes doing full stick inputs to try and provoke the problem. Nothing happened in stab, alt hold or loiter. I then landed put a mobius cam on the front, went to about 20 feet and engaged loiter. After about 20 seconds the quad rolled to the right very rapidly. Fortunately it recovered before hitting the ground without damage.
I have looked through the log but I can’t see any reason for this, can anyone help by looking at the log and suggesting what I can do. I have previously checked the vibration levels and they are fine. I’ve even changed the apm and gps/compass.

2

Definitely a powerplant failure. Front left.

Could be signal wire, power wire, ESC (over-current/heat or sync issue), motor wire, motor, prop adapter, prop.

3

OK thanks. Am going to change all ESC and motors asap and try again. Thanks

4

Changed the motors and esc’s and the problem is gone. Many thanks. Will now have to find out whether it was a motor or esc.

5

[quote=“jschall”]Definitely a powerplant failure. Front left.

Could be signal wire, power wire, ESC (over-current/heat or sync issue), motor wire, motor, prop adapter, prop.[/quote]

I’m interested that you say front left motor and how you worked that out? I did indeed have an issue with the front left motor but, the video that I have of this failure shows the copter doing a full flip to the right (clockwise). It stays perfectly level and recovers after a single rotation.

6

[quote=“jeffridj”][quote=“jschall”]Definitely a powerplant failure. Front left.

Could be signal wire, power wire, ESC (over-current/heat or sync issue), motor wire, motor, prop adapter, prop.[/quote]

I’m interested that you say front left motor and how you worked that out? I did indeed have an issue with the front left motor but, the video that I have of this failure shows the copter doing a full flip to the right (clockwise). It stays perfectly level and recovers after a single rotation.[/quote]

Just had another look at the video frame by frame and your correct it did indeed flip to the left - would still be very interested in how you found that out - I still have the motor and esc for the front left so will do some tests on it - I susspect the esc (12a mystery). Once again many thanks for your excellent analysis.