Can't attach physics constraint to actor

First of all sorry if I’ll be messing up terms, I’m new to UE4.

I’m working on a crane system that I want to control to transport an object around. For this, I wanted to create an actor and apply a BP to control it, then attach a physics constraint to it in order for it to move objects around.

This is my problem currently: the lower cube is a static mesh I’ve constrained to my load using a physics constraint, and it works for the purpose of the simulation. However it doesn’t move!

I’ve managed to program the basic crane functionality, this is the BP I’ve put together that does its job. I’ve then placed the cube with the BP in my scene (if I understood correctly it is now an actor) and, as you can see, it moves left (it’s the upper cube in the video).

However, whenever I try to attach the load to my moving cube using the physics constraint this doesn’t work. Even though the physics constraint is attached to the crane, it stays still when I start the simulation. You can see the result in this video

I don’t really know what to do, and I don’t know now why I can’t attach the physical constraint to the moving cube, even though this worked with a static mesh.

Thanks in advance.

I actually managed to solve this. Not only I had to specify the constraint actor for the physical constraint, but also the component! With this now it works.

BTW I also had the same issue, but sadly your solution didnt work for me. As I was attaching a cube, to a scene component. Then I wanted to move the scene component and it move the cube. But solution was same as yours + using a mesh component - set to hidden instead of a scene component.

I was having the same problem after following this tutorial: UE4 Connect Skeletal Mesh with object using Physics Constraints in Unreal Engine 4 Tutorial How To - YouTube. But selecting the component name like you showed fixed the issue!!!