I'm not sure if the nylon bearing was defective, unsuitable for this application or just a bad idea, but it failed miserably when rounded over the edge of a hard countertop. 3 1/4 hp Hitachi motor worked under top speed and the nylon portion of the bearing disappeared during operation. I could see something was wrong, but with the smaller metal bearing that the plastic was once attached to still intact, I completed the pass and it took me a minute to figure out what had happened. It was a sight