Droopy Arm Causing Erratic Flight

Config: 450mm TBS Discovery style quad. Affectionately known as Dead Cat. Pixhawk running 3.5 firmware. Wraith32 V2 ESCs. T-Motor Navigator motors.

Swapped out ESC and Arm 3 still dips. Swapped out Motor with no change. Here’s a pic:

Red line is Throttle In (Ch3). Not sure what else to try. Could it possibly be a bad solder joint in the CH3 motor output? (between FC and the ESC?).

In addition to this you can see where I suddenly raised the throttle around 7.5 in the graph. This was in response to the copter suddenly loosing altitude. Throttle had no effect as the copter landed (slightly hard but not bad).

Here’s the BIN file if you want to have a look: 2018-08-29 06-35-11.bin (418.0 KB)

Tempted to put the old Turnigy ESCs back into play and see if it behaves differently.

Any thoughts?


Anybody have a chance to look at the log? Scratching my head here.