Creating a freely rotating, movable object

I’m not extremely experienced in Unreal Engine, but I have an idea for a very simple game I want to begin developing. I don’t want to say too much, but the player should be able to interact with an item that is hinged to another item, which is hinged to another. So the 3 pieces are able to fold and expand entirely by physics along one axis. I’m terrible at explaining so here’s a slightly less terrible mockup.

I’ve tried to create each item with interlocking pins/holes, but if I give them complex collision, the engine crashes immediately upon playing. I’ve also tried to use sockets and restrict the x/z rotation and movement, but the child objects fall to the ground.

I’d appreciate even the slightest nudge in the right direction. Thanks!