After a small crash into a tree my H3-3D was off horizontal level. The GoPro would tilt 2-4 degrees from horizontal (1st picture). Slightly noticeable in person, very noticeable in videos and pictures. I had tried an accurate IMU recalibration with green check mark and also re upload the lates zenmuze firmware. Neither solved the horizontal tilting. Pretty simple. I put two small washers between the phantom and gimbal mounting bracked. Placed the washers on the high side of the unleveled gopro to counter the tilting. Now the GoPro is level. You could add more washers depending on how unleveled your gimbal is. No bending of gimbal arms needed. The original gimbal to phantom screws are too short on the side where the washers are added. I bought longer screws (M3 .50 10mm).