How do I connect two objects and make them rotate?

So I have two objects and I want them to be connected and be able to rotate BOTH of them from left to right. One object acts as the parent object and the other the child, so that when I rotate the parent object the child object moves with it but when I move the child object, it rotates independently from the parent object. Help would be much appreciated, thanks.

Use the AttachToActor node, when rotating child, use Relative Rotation.

are they touching in the same spot everytime cus if that is true that you can have the game replace the model when they touch if they do that.

I did that and it seems to work however, the child arm now jumps to the other side of the room while the parent arm stays in its original position once I click play. Is there a reason for this?