Magnet failure is rare. The endbells are only pressed into place, so after a while they simply work loose- just like feigaos and old neu motors. Easy fix is just to glue them in place with some red loctite, or even do like BrianG did and use 2 or 3 tiny little screws to hold them in place, like how the vxl and newer neus do. Mike's motor clamp is another great solution, if he ever gets around to making them again.. *hint hint*
