I was recently flying my Tri in AUTO mode, flying a mission I had previously flown the day before, when to my horror it appeared to go completely nuts before free falling 100m to the ground. On review of the video from an onboard gopro you can clearly hear the yaw servo jittering before going crazy to the point that the APM board went briefly into FailSafe mode then Disarmed in mid flight. ( not good )
I’ve been flying multirotors for a while now but have recently progressed / transitioned from a KK2 control board to the APM2.6. Over the last couple of months I’ve been working my way through the various flight modes and coming to terms with the seemingly endless functionality of Mission Planner.
Until now I’ve never had an issue with servo jitter ( on this setup or previous tricopers I’ve built ) so I’m a little confused as to just what might be causing the issue. So I guess what I’m looking for is a little guidance / wisdom on pining down the cause of the servo jitter. ( Having an unscheduled 100m free fall is not something I wish to repeat. )
Ive listed as much detail as I can on my current setup ( as it was on that day )
Frame: FliteTest – BatBone
Motors: NTM Prop Drive Series 28-26A 1200kv
ESC’s: HobbyKing 30A BlueSeries Brushless Speed Controller
Servo: Turnigy XGD-11MB Digital Mini Servo
Battery: Turnigy 2650mAh 4S 20C
APM 2.6 Set Side Entry (external compass)
-3DR Radio Telemetry Kit - 915 Mhz
The power wiring is as per the documentation for using the Power Module and using power from one ESC to power the servo.
Power Module and using Servos with BEC power from one ESC
- If you have a power module and you are using servos Remove JP1.
- Provide APM and receiver power via the power module connected to the APM’s power module connector.
- The BEC of a single ESC must provide sufficient power for all your servos.
- When connecting your ESCs to the OUTPUT connector clip the BEC power leads on all but one of the ESC’s connectors.
- Or connect only the ESC signal wires to the OUTPUT connector for all except one ESC.
- And on that ESC connect all 3 wires to the OUTPUT connector.
I’ve included the log data from the APM and from the mission planner (as I had the telemetry link running at the time )
And a link to the gopro footage on youtube.