Make a kinematic only model

Hello everybody, I have a robot model written in urdf and I want to make it move with a linear/angular speed command. So I have modified the planar_move plugin. I also had to make some links (not close to the ground) kinematic to avoid bad orientation in turn. But I still have a small bias in the trajectory following (which works fine with the diff_drive plugin). I tried to disable gravity, set constraint solver iterations to 0, set all the links to kinematic. But when the robot receives an angular speed (take a turn), all the links falls apart. Some possibilities : - Maybe the little bias can be corrected with follower's parameters (but I don't want to change them to test that specific version) - I am probably making some mistakes in using kinematic. I saw some posts about it but no answer. What is the steps to follow in order to use a kinematic only simulation ? Thanks in advance.