An apparatus and method for an automatically pivoting return side idler trainer for returning a drifting conveyor belt back to a central position during operation. The trainer includes a non-collinear shaft having ends fixed to the conveyor structure while a non-collinear tube is pivotally mounted to the shaft. A tapered roller element is rotatably mounted to the tube on each side of the pivotal mounting. The shaft and tube include an offset angle that is determined by the taper angle of the tapered roller elements such that when the trainer is installed, the profile of the roller elements form a level surface along the trainer, parallel to the belt return side, regardless if the belt has a straight or cupped profile. A second embodiment uses a non-collinear shaft to which the tapered roller elements are rotatably mounted and whereby the shaft itself is pivotally mounted to an external conveyor structure.