Dear all using ros indigo, I have created a differential drive robot based on the
http://www.generationrobots.com/en/content/75-gazebo-and-ros and I have put the code in my repos: https://github.com/behnamasadi/mybot/

When I try to move the robot it slids in its place, https://www.youtube.com/watch?v=a8ju5Cu9mgI&feature=youtu.be

I have set different values for mu1 and mu2 but that didn't help the problem, mass for wheel is 5 and for the chassis is 50. Any ideas?