Tarot 680 Iron-man unstable

I have the Tarot 680 iron man with PixHawk4 Qx-motor QM4208 380kv running 15x5.5 t motor props. the problem I am having is when I try to take off and get about a foot off the ground its starts to shake and rock around.and very unstable I have balanced every thing so I am wondering if I have it over Propped or pids need to be setup ? if its the PIDs what would be a safe starting point I have never worked with the PIDs before … With my tarot 680pro i just used Auto Tune .and my other quads.
Thank you for any help…

Running larger props with powerful motors can make the machine pretty unstable as you have found out.

Have a look in the Setup area of http://ardupilot.org/copter/docs/autotune.html for larger propped machines.

Especially the aggressiveness of the tune.

If it wont hold level flight long enough to autotune you may need to lower the PIDs somewhat.

There’s good info in the Wiki

Thank you for the information

@ DARKHOURS How you make it stable? Can you please share your parameter file?

You wont fix yours by grabbing someone elses parameter file. There’s too many differences between ESCs, props, motors, battery and current flow, COG… The list goes on.
The only way is to work through the calibrations and the tuning guide carefully.

@xfacta Yes you are right, just for reference i wanted it, i shall not straight way write them on my fc