Tricopter - 3rd & 4th flight attempt

Changes since last flight:

1. Reversed gyro on right arm
2. swapped gyro gain channels on receiver

These changes seemed to help. The tricopter would take off without immediately flipping over. However, it wasn't stable on the yaw axis, and would start spinning and translating sideways. I was able to lower it to the ground each time. However, the HXT900 servo I used for the tail rotor wasn't quite robust enough, and stripped out.

I'm going to replace the HXT900 with a parkzone DSV1300M- I believe this is a metal gear servo so it should be more robust.