Hello all you quadcopter people,

I just recently built my first quadcopter (not from a kit). It works great except my flights are always less than 30 seconds because my propellers keept snapping when the silver screw caps holding them on unscrew themselves. The first few times I think was due to the fact that I didn't balance the props even though I was using the 12x4.5. After I started balancing my props the vibration of the legs stopped but the caps would still sometimes unscrew themselves regardless of the lock-tight I used. And when the caps come unscrewed the props always snap probably because of vibrations. Anybody have any ideas on how I could fix this problem? Any help would be very much appreciated.

Thanks!

Nathan