I hope someone has a solution for this problem. I have a relatively new Delta benchtop belt/disk sander. The problem is that the disk plate won't stay tight on the shaft. The little set screw that holds it on the shaft comes loose after a few minutes of use no matter how tight I can get it with an allen wrench. If it weren't for the dust guard around the disk, the thing would probably fall off and go skating across the garage floor. I've replaced the set screw twice thinking that would fix the problem but no luck. I suppose I could put a drop of Loctite on it but then I would never get the screw loose if needed. Anybody got any suggestions?