Abstract: An abrasive belt machine is disclosed as including a stationary base for mounting parallel, belt drive and tension control rollers and a support arm having a free end portion projecting from the base; a contact arm for mounting an idler roller; mounting means for removably mounting the contact arm on the free end portion of the support arm for pivotal movement about a belt position adjustment axis disposed parallel to the axes of the belt drive and tension control rollers and the idler roller; and first, second and third tension rollers mounted for movement with the contact arm and serving to guide an abrasive belt for passage over the idler roller, during pivotal movement of the contact arm about the adjustment axis through upwards of essentially 180 degrees.