Method of multiple station drilling

A method for performing a large number of repetitive but variable machining operations on large, plate-like workpiece comprising the steps of:

• sequentially loading clean cast workpieces onto a plurality of fixtures mounted on a rotatable turntable at a loading station;
• indexing said turntable such that each one of said fixtures is rotated from said loading station successively proximate to and in registry with a plurality of machining stations spaced about said turntable, such that said workpieces each face successive ones of said machining stations;
• positioning a first plurality of machining tools at at least one of said machining stations repeatedly and independently of each other to perform a plurality of machining operations on different, noncontiguous areas of said adjacent workpiece;
• repeatedly and independently positioning a second plurality of machining tools and performing a second plurality of machining operations on said adjacent workpiece at another of said machining stations, each of said second plurality of tools performing said second plurality of machining operations on different areas of said adjacent workpiece, said different areas each being contiguous to areas containing said first plurality of machining operations;
• and
• sequentially unloading machined workpieces from said fixtures at an unloading station after said turntable has indexed said fixtures into registry with all of said machining stations.