How to tighten motor screws?

[swwrobotics]

So our team's screws for our shooting motor keep shaking out because of the slight vibration from our pneumatic wheel. It is a direct drive to the wheel, and the motor is mounted underneath a plywood board with two screws. We don't want to use Loctite or any glue to hold in the screws because we want our motor to be replaceable in case anything goes wrong with it.

So has anyone else been experiencing this? We have balanced our wheel with metal bearings to reduce the vibration but our screws still like to come out and get jammed in the wheel. So are there any suggestions for fixing this problem like dampening the screws with rubber bearings or something like that?