Newbie struggling with padlock animation

I have modeled a simple padlock and am now trying to animate the process of twisting and closing the loop part of the lock. When blender interprets the path to close the lock, it takes the center of the bounding box of the loop and directly transposes it to the closed position. I want that the loop twists around the arm that is connected to the base of the padlock. How should I make this constraint. From the docs, the only way that seems to work is a constraint from the gaming engine. This seems like more than I need. I feel like I am missing something basic here.

Help appreciated.


You need to move the object origin to the axis you want the loop to rotate. Then keyframe its location and rotation at key moments (I / Loc/Rot)

Select the location you want. Shift+S / Curser to Selection, then in the toolshelf (T) use the Origin button to move the object origin to the location of the 3d cursor

See attached example blend file


padlock.blend (104 KB)

Thanks for the response. What I actually did in the end was add a bone to the loop and animate the bone. Not sure if that is an efficient or elegant solution, but it worked.