Strange intermittent un-commanded Yaw Skyjib 6 Ti

[Efliernz]

I'm throwing this out there in the general as I'm not convinced this is a machine-specific issue...

DW Skyjib Ti with retracts.

Hexa Dimensions are:
Width Motor centre to centre: 1020mm
Weight: 7.85Kg MAUW
Height: 610mm gear down
TX: Spektrum DX9
RX: Spektrum AR8000
Telemetry: Spektrum TM1000
Gimbal: AV200
ESC: Turnigy Plus 40A
Gear: Droidworx retractable
Motors: Tiger Motors MN4014-11
Props: Tiger Props 17x 5.8
Hoverfly Pro controller.

I'm trying to help a mate that lives 1000Km away on another island. He bought a Skyjib 6 Ti with retracts last year and has been battling to get it up to spec. This is what's happening...

Problem… at random moments during a flight, the copter yaws right, (unable to control the yaw), then returns. Some yaw movements are small, occasionally its nearly 180 degrees.

This is what has been changed so far without improvement:

Spare HF Pro controller (mine)
Spare NAZA
All ESC’s changed
UBECs powering the HFP changed (running 6S so he needs one)
UBECs moved away from FC
RX changed
TX changed
A/V and Telemetry and anything that can create interference removed.

He is now going through swapping each motor one at a time with a spare.

Any suggestions??? To say this hasn't been driving him nuts would be a lie!!!

Many thanks

Pete

View attachment 17199

 

[Stacky]

On phone to Wayne now, he is changing bearings on motors and finding they have wear and tear. Wonder if anyone else has experienced this probelm with it turning out to be worn motors etc.

 

[Efliernz]

That would explain his meaningless "oh?" txt to me... a man of few words for a change

 

[kloner]

have seen that and both times was motors leaving.... it is the first sign it's getting ready to hit the ground..... instability usually follows especially with a heavy load and any wind

 

[Efliernz]

He is changing all bearings... it appears they are all completed stuffed. Lots of play...

Thanks Kloner

Pete