I tried implementing the logic into the project. It did not really work out. I created a small version of the part where I tried to make it work in this playground: https://playground.babylonjs.com/#IG2RTD#2
It seems that the applyForce has no effect here. It only uses the engines gravity which is set to -0.01. When I set the engines gravity to -9.81 the box hanging on the ‘rope’ sometimes jumps. Where does this come from?
Could you please have a look on it?
Maybe you can figger out what I am missing.
You can apply an impluse to the box moving along the long box with ‘a’ and ‘d’ on the keyboard.