providing a base plate having an aperture extending from a first surface to a second surface thereof;

providing a substantially rectangular mounting post attached to the base plate on the first surface proximate the aperture such that rotation of the mounting post relative to the base plate is inhibited, the mounting post having a first shoulder intermediate the top and bottom of the mounting post, a second shoulder intermediate the first shoulder and top of the mounting post and a third shoulder intermediate the second shoulder and the top of the mounting post;

providing a first bracket having a substantially rectangular aperture sized to slide on the mounting post and rest on the first shoulder;

providing a second bracket having a substantially rectangular aperture sized to slide on the mounting post and rest on the second shoulder;

providing a third bracket having a substantially rectangular aperture sized to slide on the mounting post and rest on the third shoulder;

providing a fourth bracket having a substantially round aperture sized and positioned to receive a fastener for securing the fourth bracket to the top of the mounting post;

providing a substantially rigid tube having first, second and third radial projections with the first and second radial projections each connected to both the first and second brackets and the third radial projection connected to both the third and fourth brackets such that when the brackets are positioned on the shoulders of the mounting post, the tube is aligned relative to the sheet material pull-down mechanism such that flexible sheet material pulled across the outer surface of the tube by the pull-down mechanism is pulled in a direction parallel to the longitudinal axis of the tube.