Hi everyone, I tried to create a vehicle with soft suspension based on a model I already have. However, whenever I try to spawn it, the vehicle starts bouncing around in a very erratic fashion and does not seem to ever land and stay on the ground for long. I set the mass of the chassis as 40 and the mass of each individual (4 total) as 4 and changed the dimension of the chassis and wheels to better fit the model with these meshes. Is the bouncing behaviour purely a mass issue or something else entirely? If it helps, I'm using Gazebo 3.1 with Ubuntu 14.04.