Abstract: A machine is disclosed for producing rigid sand cores from a molding mixture of a refractory granular material such as sand and a hardenable binder. These rigid sand cores then are used in foundries for metal casting. The machine of the present invention is capable of producing several different types of rigid sand cores including hollow shell sand cores, hot box cores and cold box cores. The machine includes means for curing the molding mixture used to produce shell sand cores and hot box cores by applying heat to the molding mixture after it is placed in a core or molding box. Other means are provided in the machine for curing cold box cores by applying a gas catalyst to the molding mixture after it is placed in the core box. The machine of the present invention is automatically controlled by a circuit arrangement which can be programmed by the machine operator.