Since 1955, the U.S. has lost 70% of its large-scale casting capability. We can’t even build our own machine tool bases, and foundries aren’t coming back. Fortunately, there’s an alternative, and it starts with 3D printing and ordinary concrete. Machine tool bases require specific characteristics, including vibration damping, thermal stability and stiffness. Concrete exhibits 10 times the damping performance of cast iron, and the ability to create molds with a 3D printed polymer provides all the traditional benefits of AM, including speed and design flexibility.