My Porter Cable 4 inch belt sander after giving many years of excellent sanding, had sparking from the motor brushes and and wood dust in the sander almost caught fire, much smoke and sparks. I took the sander apart and the armature was defective and had a short. I bought a new armature from E-Replacement and foolishly I did not purchase a new bearing and collar. When I realized my oversight, I called E-Replacement and asked for help in what bearing and collar I needed for my sander. A wonderful woman spent tine with me making sure I ordered the correct bearing and collar. They received yesterday and I now have a great Porter Cable 4 inch belt sander and I thank E-Replacement for the help and very reasonable cost of the parts. Good bye Mike