I've inserted two models into Gazebo using the GUI. One is the steering cart that is already included with Gazebo, the other is a Velodyne sensor which I created following the tutorials. The Velodyne model has a single revolute joint connecting the base to the top. When I load the velodyne, I can apply a force to the join to get it to spin however, when I fix it to the cart and save it as a single model, I can no longer see the revolute joint for the velodyne listed. I can however see the fixed joint I created and also all the joints for the carts wheels.
Is there a proper way to create a new model out of several pre-existing models?
