While other motorized sanders are built more for precision, belt sanders are known for their sheer power to literally cruise through wide areas that need smoothing and sanding in no time. Part of maintaining a belt sander involves replacing the sanding belt every now and then. One way to know for sure if you need to replace your sanding belt is to run your palm against the direction the belt would make if the sander was switched on. Gently slip the sanding belt out of the belt sander, and replace it with a fresh new belt. Reapply tension by releasing the lever, so the belt is taut, and the belt sander is ready to go. Plug the sander in, and switch it on when you are ready to keep sanding. If your belt sander has no lever, then there must be another mechanism or approach to loosening the belt.