im gonna try a new idea to keep the vex motors in place
im gonna use some 6-32 screws i got at lowes to helpfully stop the motor screws from coming loose will post results in a week
cause im busy
you could also use BLUE Loctite (or any other temporary thread locker for that matter)
check out the pictures of the reinforcement 
the only thing is you need to have an extra layer of metal bolted so you can use the extra nut to keep the screw from slipping out of the motor 
:rolleyes: now if everyone went to the trouble of putting their motors like this they would wear there screws less and have there screws falling off less and would keep the maintainence issues down