True rotorcraft have lifting elements that spin on a vertical axis. I've also included gyroplane type craft where the entire craft spins, including the first published paper autogyro by Richard Neu, which motivated my work. Autogyros are kept spinning by passing through the air. No motor is required. Most use stick pin axles for stiffness and to reduce friction, however I have also used straightened paper clips and paper axles. They fun to watch and fly, but they make lots of drag, so they don't go very far.