All Portions of Conveyor Belt Running to One Side at a Given Point on Structure

CAUSECORRECTION
One or more idlers immediately preceding trouble point not at right angles to direction of belt travel.Advance, in the direction of belt travel, the end of the idler toward which the belt has shifted.

Conveyor frame or structure crooked.
Stretch string along edge to determine extent and make corrections.
One or more idler stands not centered. under beltCenter them. Use above technique.
Sticking IdlersClean & Lubricate with cleaning products
Belt runs off terminal pulley.Check terminal pulley alignment. Check alignment of idlers approaching terminal pulley.
Build up of material on idlers.Build up of material on idlers. Improve maintenance. Install brushes or other cleaning device.
Structure not level and belt tends to shift to low sideLevel Structure to stop it from sliding and shifting