The kobuki base by itself isn't going to drift, so it makes sense that the tilted inertia causes the drift. Obviously I'm able to hack my URDF by using a weightless superstructure, but I needed to repair this in a more real looking way. I attempted all I'm able to https://www.uk-exhibitionstands.co.uk/product/casonara-blimp-cube-360o-hanging-light-box-display-200l/