Need help in PID tuning

[auhouhz]

I have a 3kg hexa.

Tarot FY680
SunnySky 700kv motors
SimonK 30A ESCs
12X4.5 props
DX8 + Sat

Please see this video on PC for annotations:
http://youtu.be/pIQmnlgs14I

PID

30 june pid.JPG (80.94 KiB) Viewed 4854 times

30 june radio.JPG (84.52 KiB) Viewed 4854 times

mot throttle.JPG (92.47 KiB) Viewed 4854 times

Mot roll.JPG (90.44 KiB) Viewed 4854 times

In normal mode, it flies ok but have small and fast oscillation on the roll axis. on one occasion, one motor seems to have stopped for 1 sec. In position mode, it have the same small and fast oscillation on the roll axis and it cannot hold altitude. It will slowly drop until it touch the ground.

Please guide me on how to resolve the oscillation and alti hold.

Thank you.

[joebar.rc]

Tuning takes time but some starters:

Fast oscillations: to high tilt rate D, try it with lowering it in steps of 100, maybe around 4000
Still oscillations? or when you roll, let go the stick it 'bounces' around the roll: lower the angle P (maybe to 35?)
Slugish respons, lower the angle D.

First resolve these before going to the next phase, and a lot is already written on the site and in the forum