Hi Farbtopf,

I was looking for something to do while browsing these forums and your post caught my eye so here is 1 possible solution that is very fast efficient and a pretty simple setup.

1, Start by making a line of very basic geometry ...I used a simple poly cube ( 6 of them evenly spaced ) snapping them to grid locations.

2, Select all 6 cubes and under the dynamics menu - Soft/Ridged bodies create an active ridged body.

3, Select the first cube and shift select the next one in the row then goto soft/ridged bodies menu create a spring constraint...then move to the 2nd cube and shift select the 3rd cube and create a spring again, do this until each cube is connected with a spring between them.

4. select the cubes (apart from the first and last one) and goto fields menu and pick gravity....set the frames to around 300 and play and you will see the magic of dynamics in action...

5, Even though we didnt include the first or last cube in the gravity they still get affected by the spring pulling on them....I guess you could use passive rigid bodies for those but hey Im winging it here....so anyway to stop them flying away, select the first and last cube and in the channel box you will see an attribute called "Active" under rigidBody....set that to 0 - off and play the animation again.....they will act like anchors now.

6, Now its really up to you to set how flexible the string will be....by using the spring stiffness/ damping / spring rest length (spring attributes) and the damping value of the (rigid body) attributes....the springs will obviously show how the string will react

7, Draw a CV degree 3 curve along the line of the cubes putting a point at each cube...this will be the exact path of the string driven by the cubes...now goto component mode and select the first control vertex and under "animation" menu - deform / create a cluster (This is so you can parent the Vertex of the curve to the cube)....create a cluster for each vertex so you will have 6 matching position of the cubes

8, select the "c" for the cluster and shift select its cube and press P to parent them together / this will make the cluster follow the cube around.

9, Basic modelling skills...create a nurbs circle and extrude it along the spline we just setup.....voila you now have a dynamic controlled string...hide the cubes and springs etc and hit play

Job Done : )

Animating the first and last cubes positions is all thats left to do

I have attached a scene file for you to pick apart....

Have a good one.