Hi Folks I want to share with you a problem I had with a router bit. I have a couple of half circle pieces of plywood laminated with formica. I want to copy their shape onto plywood and then make another pass with a camfor router bit. I will not need the half circles originals after I am done. I used a streight bit with a ball bearing, and the bearing lifted up and I did not know it was loose. I screwed the half circle onto the plywood and went to work. The bit tore into the formica edge and left a gouge on the edge. This was a benifit for this job but I did not want to do it this way. But since it started this way, I finished it this way. The ball bearing lifted up above the original piece of wood and the quarter inch shaft replaced the ball bearing. From now on I will check, and I am fortunate that it did not hurt this job. John Sherrer.