The Foundry is a Vaul building responsible for constructing basic ground forces.
All infantry units are built by way of psionic/nanotech assembly lines. Each Foundry is completely automated to maximize efficiency (Star Trek Enterprise: Dead Stop).
Due to their unique properties, most Vaul alloys need to be in liquid form before taking on more durable properties (Marvel: Adamantium). Thus, multiple vats of liquid alloys and nanobots are stored within the building before die cast construction. The machinery manipulates force fields to shape basic parts of the various machines. So units are not made, they are poured (Transformers G1/Beast Wars: the Ark; Halo: Sentinel Constructor Factory). Short-life nanobots are infused into the alloys to build complex circuitry within the parts before losing power. The newly formed parts are levitated, by modified tractor beams and nanites, onto the assembly line and put together in a fraction of the time it takes for the most advanced Terran and Protoss factories.