Big machine tools are just like smaller ones. And they're not

摘要

Relatively speaking, one shop's big bruiser is another's minimachine. So for this discussion a "big" machine tool can be defined as a machining center with a work envelope larger than a 36" cube or a lathe that can handle a workpiece greater than 2.5' in diameter. Defining what constitutes the step beyond big is less clear; most probably it is determined by a machine's degree of specialization as well as its size (See sidebars on pages S2,S8 and S10). Obviously, big machines are similar to their smaller brethren in operation and results. However, the physics of processing a massive work-piece-as well as market forces that include shrinking lead times, controlling costs and machining challenging new materials-require large ma chine tools to offer features different from those of smaller machines.