Hi, I'm a fledgling Modder from the US. Im new to sketchup and have a rough Idea of what i want to do for a case and it involves a custom fan that has the outside cover rotating pulling air in and the center blowing air out. The idea for the fan is to use a corkscrew style fan (S-type fan) to pump the air up and out the middle of the fan assembly while the outer layer of the assemble spins the opposite direction sucking cool air in and down. The Case is in the rough shape of a cylinder. The fan assembly should run throughout the case (from one end to the other). I just don't know how to use sketchup right and all. I can "see" the case, but have a hard time going to paper.