Running circles around ball head milling times


What does 5-axis machining have to do with metal stamping and wire form production? Not much unless you work for Rapid WaterJet Design (RWD), a division of Burnex Corp., Ringwood, Illinois. There you’ll find Jim Walslager, RWD’s senior programmer who has worked on a variety of “complex precision”, one-off stuff “recently for the on-demand industrial parts market Xometry. It is its main customer outside of the parent company.

Jim Walslager (top right, in front of the right machine door) and the team at Rapid WaterJet Design, a division of Burnex Corp. (All images provided by Burnex)

“We’ve had a Hurco (machine tool) for almost a year now,” he said. “When we bought it, I ordered several circle segment cutters from Emuge-Franken. I implemented them from the start because I knew what they could do. “

Burnex Corp. is a family-run manufacturer specializing in precision metal stamping. The company has been in business since 1972 and prides itself on its high speed planetary gear stamping and bending technology, which it calls the “Burnex Advantage”. The company has been with the company for an average of 18 years. Its punch press capacities and systems range from 20 tons to a servo controlled 110 press, offering customers an in-house, collaborative engineering and design approach.

In 2012, the company’s owners decided to buy a water jet to support near-net-shape cutting for in-house precision punching. A second machine followed shortly afterwards. Due to the growing demand for outside work, they decided to start Rapid Waterjet Design as a second company. RWD has strategically positioned its water jet machines, CNC milling machines and wire EDM machines within the same production workstation. Each workstation is able to work independently, but all of them also complement each other by reducing material waste, CNC milling and EDM runtimes, resulting in significant component cost savings. RWD has evolved over the years by acquiring additional CNC skills, including the five-axis Hurco unit.

It is estimated that milling the conical surface with a ball end mill would have taken approximately five hours per part. The circular segment cutter from Emuge-Franken did the job in 38 minutes.

RWD still makes stamping and forming tools, but also produces jigs and fixtures for the medical technology manufacturer Hill-Rom, machine components for GF Machining Solutions and lots of “crazy” stuff for Xometry. “It works very well with the water jets, because we cut parts out of the sheet material near the final contour and then finish processing them on the Hurco or one of our three-axis vertical machines,” said Walslager.

The Hurco is a five-axis machining center of the type VMX SRTi 60. With traverse paths of the X and Y axes of 60 × 26 “(1,524 × 660 mm), up to 60 tools and a maximum spindle speed of 16,000 rpm, the swivel head is Rotary table machine equipped for a wide variety of complex milling tasks.

Walslager was challenged with such a job earlier this year. At first glance, the part looked like a perfect CNC lathe candidate, except for the fact that it contained numerous flats, holes, and internal pockets that required extensive milling.

Walslager was happy to have invested in circular segment milling cutters from the high-performance cutting tool manufacturer Emuge-Franken NA, West Boylston, Massachusetts. I didn’t even try because the CAM system said it took almost five hours per part. The emuge cutter did it in 38 minutes, ”he said. “It started out as a 100-pound block 6061-T6 and ended up weighing just 2.72 kg.”

At the time, he was a relative newcomer to both five-axis and circular segment milling and needed a little programming help. He called Dan Doiron, Milling Product Manager at Emuge-Franken NA. “It turned out to be a lot easier than I expected,” said Walslager. “All I needed for the toolpaths was to use Mastercam’s morph and parallel functions with a surface slope option. It’s easy.”

Senior programmer Jim Walslager walks through the RWD facility in Ringwood, Illinois. He’s been doing a lot of “complex, precise, one-off things” lately.

It was made even easier by Doiron’s offer to provide RWD drawings of the tools, which he then imported directly into Mastercam. The geometry of the part was critical, notes Walslager, because CAM software can get “a little fussy” when working with the relatively large arcs found on all circular segment cutters, and dimensionally accurate CAD files saved him hours of work.

In fact, the project was so successful that RWD took over another conical part, this one made of C101 copper. Here, too, the milling cutters from Emuge made the difference between long hours of profiling with a spherical milling cutter and a far more efficient circular segment machining.

“Before we got the Hurco, I had seen how circle segment cutters worked on YouTube, but it wasn’t until I actually started using them that I realized how effective they can be,” said Walslager. “And for anyone who’s nervous about programming one or isn’t sure which toolpath to use, I tell them to give Dan a call. He is always very helpful and responsive and welcomes a Zoom call. The other day he showed me how to break up this complicated part feature and mill it from two directions with a lens shape cutter. I thought, ‘Wow, this is really great. Thanks Dan. ‘ ”

For more information on Rapid Waterjet Design, visit rapid or call 815-728-1929. For more information on Burnex Corp. can be found at or by calling 815-728-1317. For information on Emuge-Franken NA, visit or call 800-323-3013.


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