Copter not stable and jumps constantly

Hello,

We have a hexacopter with Pixhawk cube and Mini Carrier Board and T-Motor F45A ESC. The copter jumps about 5cms up and down constantly in the air. After a while it stays still but as soon as we give a little throttle it starts jumping again. I have uploaded a video and the log file in the link below. Could someone have a look and give any suggestions.

https://drive.google.com/open?id=1QB4BAxp2VJC--QIyM2XbOnlSQxZBawu2

Regards,
Pavan

hi @Pavan
it seems that there is a problem with you transmitter or receiver, your CH3 ( throttle ) is oscillating

Hi @hosein_gh , the throttle oscillation was manually done by the pilot to replicate the jumping when throttle is given. In the picture attached you can see that even when the stick is in the middle position the motor outputs move up and down within a range.

Did you flowed tuning instructions ?
http://ardupilot.org/copter/docs/tuning-process-instructions.html

Assuming that tuning is good and filters are set.
Did you put any vibration dampening under your Cube ?