Drive Wheel - Front - Back - Solid Fill

I too was concerned about the weight of the vehicle possibly crushing these wheels due to the original file having an internal cavity. I had tried messing with support but I wasn't really satisfied with it so I grabbed the original Solidworks part from GrabCAD and created the solid of the cavity and added it to the file. It will now slice with full normal infill where the cavity used to be. I am doing 2 shells with 30% infill (also how I did a few of the original wheels without any fill in the c