Pixhawk issue Quad flips at minimum throttle

[Paul-H]

Hi all

Got a bit of an odd problem with my Pixhawk and Quad I am building.

On the bench it is all calibrated and the motors start fine

Outside once armed the motors I have a problem

I have a 3 position switch set to Stabilize, Altitude Hold and Loiter and a second switch set for RTL

No the problem, with the props off the motors appear to spin up fine regardless of the switch position, although stabilize is the starting position.  But once the props are on, in stabilise mode as soon as I touch the throttle the motors spin up really fast and the model flip, but if I select Alt hold or Loiter they spin up fine.

Now obviously this is something I have done wrong, but I just cannot find it.  Anyone got any clues as to were the problem might be.

I have performed ESC calibration in Mission Planner and done all the compass calibrations.

Thanks for any help with this

Paul

[motofox]

It will be somthing really simple like a motor spinning in the wrong direction or a prop on upside down ? maybe even the pixhawk direction.