and details. Creating motion control systems to incorporate those variables became a major innovation for leading waterjet manufacturers in the early 1990s, with John Olsen of OMAX Corporation developing systems to precisely position the waterjet nozzle while accurately specifying the speed at every point along the path, and also utilizing common PCs as a controller. The largest waterjet manufacturer, Flow International (a spinoff of Flow Industries), recognized the benefits of that system and licensed the OMAX software, with the result that the vast majority of waterjet cutting machines worldwide are simple to use, fast, and accurate. Operation All waterjets follow the same principle of using high pressure water focused into a beam by a nozzle. Most machines accomplish this by first running the water through a high pressure pump. There are two types of pumps used to create this high pressure; an intensifier pump and a direct drive or crankshaft pump. A direct drive pump works much like a car engine, forcing water through high pressure tubing using plungers attached to a crankshaft. An intensifier pump creates pressure by using hydraulic oil to move a piston forcing the water through a tiny hole. The water then travels along the high pressure tubing to the nozzle of the waterjet. In the nozzle, the water is focused into a thin beam by a jewel orifice. This beam of water is ejected from the nozzle, cutting through the material by spraying it with the jet of speed on the order of Mach 3, around . The process is the same for abrasive waterjets until the water reaches the nozzle. Here abrasives such as garnet and aluminium oxide, are fed into the nozzle via an abrasive inlet. The abrasive then mixes with the water in a mixing tube and is forced out the end at high pressure. Benefits An important benefit of the water jet is the ability to cut material without interfering with its inherent structure, as there is no heat-affected zone (HAZ). Minimizing the effects of heat allows metals to be cut without warping, affecting tempers, or changing intrinsic properties. Sharp corners, bevels, pierce holes, and shapes with minimal inner radii are all possible. Water jet cutters are also capable of producing intricate cuts in material. With specialized software and 3-D machining heads, complex shapes can be produced. The kerf, or width, of the cut can be adjusted by swapping parts in