Fulfilling customers' wishes sometimes can take years and you might have to start a new company to do it.
Walter Maurer used to be the director of Waterjet AG (www.waterjet.ch) in Aarwangen, Switzerland, which has been cutting hard-to-mill materials such as glass and plastic for 20 years, using extremely high-pressure water and an abrasive such as garnet sand. Though the company was successful, some ideas and requests remained undone, although Maurer felt the technology could and should be able to do these jobs, too.
"There were always parts we couldn't do, such as those for watch companies, that were just too small and precise," Maurer says. "Then, when the economy was slow in 2000, we took our drawings, contacted Switzerland's University of Applied Sciences, and worked with engineers there to study fluid dynamics, specifically how particles accelerate to form a water jet. We learned to produce a laminate flow that was perfectly round, how to better add abrasive, and discovered that fast and precise aren't the same for accelerating particles."
To help them build the new "micro waterjet" abrasive waterjet machine, Maurer and Waterjet AG partnered with former client Max Daetwyler Corp., a 63-year-old builder of plate polishing and engraving machines for the printing industry. They formed Micro Waterjet LLC in 2001, and used their research to begin constructing the micro waterjet machine, which runs at 60,000 psi, produces a 300 µm stream, and accelerates particles to 700-800 m/sec.
The 40-employee partnership's micro waterjet also replaced some earlier control software with NUM's Flexium for its CNC controls because it can handle two processes at the same time. They also secured National Instruments' LabView software from the university to help check pressure signals, regularity of its machine fittings, and process stabilization to improve quality control. The machine's positioning accuracy is ±3 µm, and its contouring accuracy is ±10 µm.
Maurer adds that micro waterjet is overcoming traditional prejudices against waterjet cutting as wet and dirty, and is bridging the gap between existing cutting technologies. In fact, micro waterjet has many advantages over electrical discharge machining (EDM) and laser technologies because it uses less power, generates no heat, and so it cuts with minimal burr and superior edge, but does it without creating heat-affected zones (HAZs), heat deformation or other damage to the material it's cutting.
Since its introduction in Europe, micro waterjet has been making exquisitely detailed parts for manufacturers in aerospace, automotive, electrical, job and machine shops, art and architecture, medical, motorsports, watch components and other advanced, specialty applications.
"In the future, I think we'll be able to make our waterjet even smaller and work at higher pressure, probably 100,000 psi," Maurer adds. "We're at work on a processor that will let us correct the jet back to round in real time. We'd like to get the acceleration stream down to 100 µm, but there are no parts available yet. These are new problems, but they give me something new to invent."