Total lose of altitude small changes in yaw

ArduCopter Copter 3.2
1

I am a total beginner, and have just built and tested my 3DR DIY Quad Kit. I am having a couple of issues.
I currently always fly in alt hold mode or Loiter mode. My roll and pitch controls work well, but with even small changes in yaw, my quad will lose altitude and lower all the way to the ground. I can give full throttle, or cut power and it still just lowered to the ground. To get it to work again, I have to let it disarm and rearm then I can take off.

Also, I have noticed I can take off in the grass, but doesn’t seem to have enough power to take off on pavement. I need to test this more to see if this holds.

Has anyone had this problem? Could someone point me to information to diagnose the cause?
Thanks,
Rich
Panama City Beach Fl

2

Are the props on the right way and battery sound Richard? Also…

Cheers

Gary

[infocopter][/infocopter]

3

I did a ESC calibration ( I had not done a calibration yet), and the flight went great. I was able to fly in all directions while in loiter mode while rotating the copter (yaw). The altitude held steady the whole time.

The altitude still drifts a little, but I probably need a little PID adjustment.

Thanks.