Abstract: A central mixer is coupled to a transport bucket which moves from a home position to anyone of a number of core machines. An automated computer-based logic controller monitors the state of all core machines and responds to an appropriate demand signal from each core machine, with a priority response. The controller selects the proper mix recipe and prepares a sand mix of sand, binder and other additives in timed relation to the position of the transport bucket. The bucket is moved to receive the sand mix and delivers it to the proper core machine, and then activates the core machine, with maximum and efficient usage of the system. The available sand mix recipes are placed in the controller memory for the particular core box machines. The controller operates a series of timers to deliver sand weight, powder additives in sequence, and the necessary binder. Internal checks insure that the sand, powder additive and binder timers have properly operated before a "mull" timer establishes thorough mixing.