The kobuki base alone does not drift, so it makes sense which the tilted inertia will cause the drift. Obviously I am able to hack my URDF by using a weightless superstructure, but I desired to repair this in a more practical way. I attempted all I can consider, and https://www.uk-exhibitionstands.co.uk/3-trade-show-mistakes-to-avoid-and-how-to-fix-them/