For the most part Craftsman, Ryobi, Skil, B&D, and a few other budget brands are throwaway when anything major goes wrong. They also tend to be hard to find parts for after a few years. Lots of people have been on the forum looking for collets and collet nuts because none are available for some of those brands. One of the issues with them is the cheap quality of parts as I pointed out with the link to your bearings. They probably buy them for about $.10 each. I've replaced some in a couple of PC sanders and they were cheap too.
Someone I consider a master woodworker once told me that a master woodworker is not someone who never makes mistakes. He is someone who is able to cover them up so that no one can tell.