I purchased apm 2.6 with external compass and GPs antivibration pads installed and loaded latest firmware 3.2.1 set up quad and installed everything as instructed
All looking good Except for bad compass health. Appeared compass and GPS working fine when turning and rolling quad in mission planner Armed and increased throttle .quad was a little unstable then accelararted full pitch and took off, major crash .Was in stabilized mode all the time, even when throttle was at it lowest point still was full speed. THis is the second time this has happened. I m still unsure how download logs so sorry bout that. As i said only had bad compass health but it appears compass was working? About to give up
Please could someone assist
Thankyou Graham
Sounds like vibrations are too high, as well as needing to properly sort out the compass but impossible to say without logs.
I have a similar problem, bad compass healthy at first, back to normal after restart,
but no roll control and drift during flight. 
Can’t help with out a log unfortunetly…read the wiki on how to download the logs
Have downloaded file and converted to text file ,size is 5mb wont allow me to send
Zip file of log hope this is the right one
Graham
looks like it went into auto tune mode…is that what you were expecting for this event?
GPS had 9 sats which is ok.
You don’t have mag or IMU enabled which would also help diagnose.
you don’t need to convert to text either…the bin files are fine as long as they are small enough for you to upload
Thanks no I didnt put it into autotune mode and I will look into how to change others.
Thankyou Graham