So after much effort with a Yuneec dealer here in San Diego, I figured out why my props wont stay on with my new Q500- the motor threadings are messed up. So now I need to send it back to Yuneec for repairs. Very disappointed in poor quality control on such an expensive toy. The DJI drones are simple to put a prop on and take off in comparison. When I expressed my frustration with the drone shop he admitted the newer Typhoons hexacopters don't have the same issue. That is why my props keep falling off and crashing my new drone!