A baling machine for forming large cylindrical bates of cut crop material and including an improved means for adjusting the relative alignment of a plurality of transversely spaced, parallel belts and minimizing wear of the belts. The conveyor belts are supported for movement in a closed path by a plurality of parallel spaced apart rollers. Means are provided for adjusting the position of at least one end of one of said rollers such that the longitudinal axis of the roller can be moved generally in a plane perpendicular to the plane bisecting the angle defined by the belt wrapped around the roller whereby relative skewing of the belt and roller imparts a force on the belt during movement of the belt and in the direction of the longitudinal axis of the roller.