title_body: How to keep my prop from flying off my motor? After finally getting every piece on my plane to work, another piece decided to be a problem. Great.
  My problem is pretty much already summed up in the title, my prop keeps flying off my motor, and I want to stop it from doing that because no prop pretty much means you crash.
  Here is a picture of the motor pod and prop unattached from each other.
  
  Here is a picture of the prop hardware that goes over the motor.
  
  Sorry if the pics aren't working, I don't use them a lot and haven't quite figured out the syntax and stuff. Any suggestions on how to keep the prop on during flight?
upvoted_answer: It looks like you are missing a piece of the prop adapter.
  There should be three pieces, the nut, the central shaft with a thread for the nut on one end and a taper on the other, and a collar that matches the taper. You're missing the collar.
  The nut forces the collar onto the taper, which squeezes the slots together, gripping the shaft. They're normally very secure but won't work without all three parts.
  Here's a picture (I get an error when I try to embed it) or you could just look for pictures of 'collet prop adapter'.
  https://shop.pichler.de/Collet-Cone-Prop-Adapter-60mm