The kobuki base by yourself would not drift, so it is sensible which the tilted inertia will cause the drift. Obviously I'm able to hack my URDF by using a weightless superstructure, but I wanted to fix this in a more sensible way. I attempted all I can consider, and https://www.uk-exhibitionstands.co.uk/product/pop-up-stand-3-x-5-bundle-straight/