How to animation with local gravity

We resolve create a rope that is animated by regular gravity plus some additional nearby “weights” traveling the length of the rope.

In Front-view makes 7 cubes with a distance of 3 units between the cube.

Twist the inner 5 cubes into active rigid bodies by default-settings.

Twist the 2 cubes at the outside into inactive rigid bodies. Of route you might as well use “active”, but since they won’t get gravity,
we don’t need to set them to active.

Flanked by the cubes create spring-constraints by settings like stiffness=50, damping=50 and rest-length=2. Of course you can play around with dissimilar settings,
I like to provide them a rest-length smaller than the coldness between 2 cubes, so the springs “pull” a bit additional. At the end you should have a total of 6 spring constraints.

Choose the 5 inner cubes and add a gravity-field by magnitude=20 and attenuation=0 (pretty much the default settings).

At this time hit play and let the simulation run about 150 frames. The cubes are supposed to loose their energy at this point.
Stop the animation. Now, go each of the 5 inner cubes now a little bit. Since they are not keyed, the after that time you play the animation from
the beginning, the cubes resolve stay in that position and you won’t have to wait.

For all 7 cubes turn on their selection-handles. Now make degree 3 curves with point snapping to each selection handle. Obviously, the curve should contain 7 cvs.