When I assembled my bmax, I found that the center gear cover (BM-302C) was putting too much pressure on the bearings if screwed tight. I took some material off it with my dremel, until the center gear spinned freely even when the screws were tightened.
A friend reported same kind of problems, but after the same treatment the bearings have been fine. He measured the broken ones, and they were elliptical by over 0,5mm.
|