To adjust the sanding belt tracking:Turn the machine upside down (Figure 4) and hold it firmly with one hand.Start the motor and release the switch immediately after observing the tracking of the sanding belt.If the abrasive belt runs outward, turn the tracking adjustment knob clockwise.If the belt runs inward, turn the tracking adjustment knob counterclockwise.Keep the edge of the belt about 7/64” (2.7mm) to 13/64” (5.1mm) from the housing to prevent rubbing. For more information, see page 2 of the manual.

To change the sanding belt:Pull the lever shown in Figure 5 to release the tension on the sanding belt.Pull the sanding belt from the two rollers.Put the new 3” x 21” (75 x 533mm) sanding belt in position on the front and rear rollers (Figure 6).Ensure that the arrows on the sanding belt and on your belt sander are pointing in the same direction.Push the lever to the rear to tension the sanding belt. For more information, see page 2 of the manual.

Only 3” x 21” (75 x 533mm) sanding belts are compatible with the Black & Decker DS321 sander.