An apparatus for forming large round bales of crop material includes a frame (10) having a pair of side walls (12, 14) and ground engaging wheels (18) mounted on the frame for supporting the apparatus for movement across the ground. A plurality of rollers (24, 26, 28, 30, 32, 34, 36, 38) are mounted for rotatable movement relative to the frame (10) and extend between the side walls (12, 14), and a plurality of endless bale forming belts (46) are trained about the rollers to define a bale forming chamber (16) in which large round bales of crop materials are formed. At least one additional chamber (48) is also defined by the bale forming belts (46) adjacent the bale forming chamber (16). A clean-out assembly (54) is provided for cleaning crop material from the additional chamber. The clean-out assembly (54) includes an opening (64) in one of the side walls (12) of the baler and a clean-out belt mounted on a pair of pulleys (56, 58) for sweeping crop material in a direction toward the opening in the side wall so that material within the additional chamber (48) is swept from the apparatus through the opening (64).