I have a rope made of simple cylinders, connected with configurable joints. They are not parented to each other. I want to restrict the motion of the rope to two dimensions, so I have all three motion settings locked and two of the angular motions settings locked, with the remaining angular motion setting as limited (and settings of limit 5, bounciness 1, contact distance 0). At the end of the rope I have a simple cube, also attached with a configurable joint using the same settings as the rope joints. The rope works beautifully at first, but then very quickly starts going totally crazy, with all of the component cylinders vibrating insanely all over the screen and bashing into everything else in the scene. I have tried every combination of settings I can think of, I've also tried character joints and hinge joints, all with the same result. What am I doing wrong here? What is the proper way to simulate a 3d rope that only operates in 2 dimensions?