Ball bearings can be monitored and tell you months in advance if they are going to die. I work as an R&D Engineer at a company (ifm) where we are designing and selling continues monitoring solutions that can prevent the destruction of your equipment for a tiny tiny fraction of the cost of the hell that happens if the machines are allowed to destruct themselves. Please write me a PM if you are interested in more details and how we can help you prevent such events in future. Best regards Johannes Hassler