How do I know when it's time to change the sandpaper in the belt sander?
Belt sandpaper is just like any other sandpaper you are using in woodworking or wood carving. As soon as it doesn’t give the results you are looking for, it means it is time for a change. You can check the grit from time to time with your fingertips when the machine is off, to be sure. If you are using it regularly, be ready to switch the belt frequently.