Ugo, > The urdf model which doesn't work contained two links and a joint. Your urdf model is correct. There is a handy tool in the urdf package to visualize a urdf xml file. Try: "rosrun urdf urdf_to_graphiz my_urdf.xml". This will create a pdf file with the urdf tree. > I tried it once more and I don't get a warning in the rxconsole. When I run it, I do get the warning. Make sure you start up your roscore and rxconsole _before_ launching the robot state publisher. However, since your urdf contained two links, the robot state publisher should not have warned. There was actually a problem in the robot state publisher, caused by the difference in link counting by the urdf and kdl. I fixed this problem, and pushed out the 1.0.2 release of the robot_model stack. Check out the change list . Wim -- -- Wim Meeussen Willow Garage Inc.