Tracking a conveyor belt can be frustrating if you don’t start off with all of the components squared up to the conveyor frame. Make sure the head and tail pulley is squared, as well as all of the troughing and return idlers. Typically, the troughing idlers center the belt on the head pulley while the return idlers center the belt on the tail pulley. The tail pulley should only be used to tension the belt and not to track the belt. A un-squared belt splice can also throw you off, but you will easily see this problem when you start running the belt.

OPERATING AND TRACKING CONVEYOR BELT
A) Before starting the belt conveyor, make sure all debris, tools and temporary bracing are clear of the belt. Caution should be exercised at all times around machinery, this is especially true when starting equipment for the first time.
B) If the belt has a tendency to run to one side or the other, it should be steered back on center in the same manner as you would steer a car.
C) While looking in the same direction as the belt travels (up the belt), all corrective action to center the belt is accomplished in the following manner:
1) If the belt tends to run to the right side, it would then require a left turn to return it to the center. Alignment should be started at the point where the turn starts. The right end of the return idlers should be pushed forward slightly or the left end should be pulled back slightly. Continue along the belt in the direction that the belt travels until the belt is centered. It is far better to move several idlers slightly than to move a few a large amount.
2) If the belt runs to the left side, the same principle is applicable, except you push the left side forward and/or pull back the right side.
3) If for some reason any of these steps cannot be completed, the alignment can be accomplished by tilting the idler slightly forward, taking note not to exceed a two (2) degree tilt angle from vertical in the direction of the belt travel. This can be accomplished by placing shims under the backside idler mount boltholes. This two (2) degree limit is to avoid excessive belt wear.
4) The return idlers should be used for belt centering in spite of their flatness. Move return rolls forward and backward in the same fashion the troughing idlers were moved.