Rotating sub actor

Hi all, i am releatively new in UE. I want to rotate child actor relative to parent. My setup is BP_Boat whose class is ABoatBase; I have a BP_Gimbal blue print whose class AGimbal. My purpose is to rotate Gimbal relative to Boat. For this purpose I use SetActorRelativeRotation or SetComponentRelativeRotation but none of them rotates the gimbal. I am really stucked. I checked mobilty of child actors but everything seems normal.
Thanks in advance for your help