Barrel Cutters Going Mainstream?
This CAM developer is gearing up to release a new toolpath strategy for new standard-issue, circle-segment cutting tools that promise big gains in tool life, surface finish and cycle time.
Courtesy of Open Mind Technologies USA, this image depicts how a typical barrel, or circle-segment cutter, engages more of the workpiece than a typical ball mill.
If CAM developer Open Mind gets its way, tools commonly used to finish contoured mold surfaces will soon have some competition. Compared to the ever-popular ball mill, barrel cutters offer longer tool life, shorter cycle times and smoother surfaces, the CAM developer claims, citing years of experience with a tool type that its software supported as early as 2002. Now, the company is working to not only double down on these advantages, but bring them to a wider audience.
This effort is a collaboration with cutting tool manufacturer Emuge. Previously, barrel, or circle-segment, cutters were available mostly as specials, says Alan Levine, managing director with Open Mind Technologies USA. Now, Emuge offers four styles as standard catalog items. Meanwhile, the latest version of Open Mind’s HyperMill CAM software will offer support for all four, as well as a brand new finishing strategy. Other cutting tool vendors that previously required weeks or mongths to grind these tools can now grind them as specials in only days, Levine says.
The defining feature of a barrel cutter is a “circle-segment” radius that, as depicted in the picture above, facilitates a much greater engagement area between cutter and workpiece than typical ball-nose offerings. Greater engagement area, in turn, enables larger stepovers, which improve metal removal rates and surface finish with less wear than a typical ball-nose cutter, the companies claim.
Four styles of barrel cutters include : general, taper (cone angle to shank), tear-drop (tangent to shank) and lens (large radius on bottom). (Image courtesy of Open Mind Technologies USA.)
Designed to improve on this basic concept, Emuge’s barrel cutter is available in four styles: taper or conical, tear-drop, lens and general. (According to documentation from Open Mind, radii ranging to 500mm can be realized with a cutting tool that has a shank diameter of just 10 to 20 mm.) Complementing the tools themselves is the CAM developer’s new HyperMill Maxx Machining strategy, which supports geometry and collision checking for all four styles. HyperMill Maxx Machining is a combination of HyperMaxx high-performance roughing, which is based on Celeritive's Volumill roughing calculation kernel and has been used by the company since 2010, and the brand new Tangent Plane Machining, which reduces finishing times through the use of barrel cutters and adds a new five-axis helical drilling process. Tangent Plane Machining will be released with the next version of the software in October.
For more specific information, including test cut results, read this report from Open Mind’s UK office.
