I started my ys-160dz with a zinger wooden prop and it blew apart and hit the house, i always reglue all joint including the fire wall, what scares me is this happens all the time and i see so many children with there dads running there engines up with kids standing right beside the prop, people just do not think, it is common knowledge to use a lock nut, i have also seen so many plastic spinners blow up and one guy told me his was balanced, i asked him if he used a torque screw driver as it is impossible to balance a plastic, i also use the hyde soft mount on all of my planes that saves me from buying a new servo or loosing a plane because of all the vibration, you can hear it when they take off and when they are flying, try one and you will never go back to a hard mount.