This 3D model is a vehicle for the Sphero, but not just a normal one. You can mount your LEGO on it.You only need a Sphero (app-enabled ball that will move at your instructions), PLA and a 3D printer to print the .stl files.You will dowload 3 files, the Base, the waggon(s) and the wheels.If you like this model, also take a look at these three:https://www.youmagine.com/designs/sphero-canholder-vehiclehttps://www.youmagine.com/designs/sphero-canholder-gopro-vehiclehttps://www.youmagine.com/designs/gopro-sphero-vehicle