Hello,

Crashed my phantom 2 hard at the weekend, bent leg and some scuffs, h3-2d popped off and landed away.

Replaced all the props cleaned it up, recalibrated on spirit level flat surface (compensated for leg)

Now it flies but drifts in a 10m or so circle, and the hight varies a little (before the crash it had no wander in any direction)
If I add the gimbal back to it the wandering is mush more irratic and it doesnt seem to get any lift.

i know it could be a hundred or so things. but any ideas on where to start?

After a hard crash, I'd take the top off and closely examine everything with a magnifying glass.  Look for loose plugs and cracked solder.  Be sure everything is rock solid.  Check the GPS antenna, make sure it's not cracked and the solder is sound.  

I would calibrate the IMU.  I would use a level to be sure the AC is perfectly level before and during the IMU calibration.  Then I would go outside in a clear grassy area and calibrate the compass.  

Then prepare to launch.  Watch the lamps during the boot up and subsequent start up.  Make sure your compass and GPS are indicating that they are working correctly.  Watch for your home point indication so you're sure it's marked.  Launch.  Study the hover.  A little movement is ok.  TBE is not ok.  Fly gently but keep it low.  See how it behaves.

Good luck

thanks for the reply. I have had it apart and the insides looks ok, didn't check the gps antenna though (doh) but i did notice that one of the props leans up to one side, the motor looks fine so i think the shell arm is twisted. So I think first port of call will be to replace that. Thanks for the reply again, i'm sure I will have more questions.