by Charles Bates
Cutting with water? Not as wild and wacky as some might think.
Abrasive waterjet has never been considered a run-of-the-mill machining technology. In its early days, shops thought it weird, typically using it only as a last resort when all other cutting methods failed. As if this wasn't enough of a setback, the process had problems with accuracy, reliability, and repeatability — not to mention noise and mess. But times are changing. Though most shops don't run out and buy one the way they would a lathe, abrasive waterjet has persevered and is now ready for prime-time action.
Today, improvements in intensifier and crankshaft pumps, nozzle designs, and controls let these machines cut to tighter tolerances, program more easily, and run more quietly and with less mess. Jobshops, especially, can profit from using the new water-jet systems because of their versatility, explains Mike Ruppenthal of Flow International Corp., Kent, Wash. He says these systems can accommodate anything that comes through the door, whether it be titanium, Inconel, copper, brass, steel, aluminum, or molybdenum.
Waterjet systems can even tackle heat treated or laminated materials, adds Dan Gotz of Jet Edge, St. Michael, Minn. A shop cutting these materials can easily produce parts with good edge quality — almost a sandblasted abrasive look on softer materials and a true machine finish on harder materials — without having the machining process adversely affect the material, as it would in conventional machining. In addition, waterjet machining often eliminates secondary processing that is necessary with other cutting methods.