For the body, just download the STL files from below and print them with PLA material. I’ve used a 0.2mm layer height and 0.4mm nozzle with 3 perimeters and 20% infill. As for the wheels, the inner part is made out of PLA but the exterior is made out of flexible a material that must be printed at lower speeds. Like that we can have more grip. The wheels have holes so I can pass a screwdriver and tight a screw. We have to add a screw nut and then insert the shaft of the motor and tight that screw. Like that it will stay in place. Then we can add the rubber part on top.