Prop guards vibrating

Whenever I did my second flight test, my prop guards started vibrating as shown in the gif. This did not happen on our first flight test only a few days before. Is anyone else having this problem or know how to fix it?

we have had some shaky prop guards in the past (not that bad) all we had to do was tighten everything and then check for cracks in the guards.

  1. Please, please, please fly your drone somewhere that has more open area and away from people and fragile objects. Having a motor cable suddenly come unplugged and the drone spinning out of control is not unheard of. I usually test fly my drone outdoors at a park or in my lawn.
  2. This is an example of a resonant frequency. Tightening the standoff screws and/or increasing thrust will likely make this go away. Some Loctite or other threadlocker on those standoffs would probably be a good idea.