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Tomak’s Fadal VMC 6030 machines a fixture that will be used to hold aircraft engine parts for fast-hole EDM. CAMWorks with VoluMill not only provides efficient tool paths, but also enables the company to verify programs to avoid clearance issues and other problems before machining begins.
Branham says one software feature he finds especially valuable is the ability to draw and add custom tooling to the CAM system’s library. At the beginning of this process, the programmer starts with a 2D sketch and uses the revolve boss/base feature to create a solid model.
This simulation depicts the tool in the photo above engaged in the part for which it was designed.
removed a lot of the guesswork from tool selection, which is important for our business because a lot of the parts we do are very complex and place a variety of demands on the tooling,” Branham says. Generating machining programs from imported solid models more quickly and accurately has helped the shop win jobs, Branham adds. As of this year, CAMWorks has provided additional benefits and in Branham credits it to You Tube, which he regards as “one of the best tools in my toolbox.” He says he often peruses 186 MODERN MACHINE TOOLS - January 2012
the free video site to stay up-to-date on the latest technologies. “I just type in a generic heading, like ‘milling aluminium,’ and see what comes up.” One video that caught his eye depicted a stainless steel roughing operation with an exceptionally high metal removal rate. The software that supposedly made this possible was called VoluMill. Impressed, he sought out more VoluMill videos. “At first, I thought they were stretching the truth,” he says. “I looked into it more and realised this was for real. This was a game-changer.”
Conventional tool paths often contain sharp, 90-degree corners that can cause spikes in radial tool load.
VoluMill generates tool paths designed to maintain a constant load on the cutting tool and machine tool spindle. According developer Celeritive Technologies, this enables cutting more aggressively while extending tool and machine life. The toolpath engine is said to be effective for virtually any material and virtually any shape that can be rough-milled in a two/ three-axis CAM system. The software works by controlling the rate of material removal. Unlike tool paths that are plotted according to the geometry of the feature being machined, VoluMill paths are designed to avoid abrupt changes in direction, such as those that occur in corners. Along with this smooth, continuous motion, the software maintains a constant, user-defined stepover and dynamically adjusts feeds, speeds and cutting depths according to tool engagement with the material. According to the developer, the resulting path avoids load spikes and ensures that users get the most from the capabilities of their machines and cutting tools.
In contrast, VoluMill tool paths are said to provide smooth, continuous motion to maintain a constant radial tool load and enable machining at more aggressive parameters.
Branham and Schaeper’s timing was fortuitous—before they could buy VoluMill, they learned that it would be fully integrated within the 2011 version of CAMWorks for 2.5- and 3-axis roughing applications. Tomak became one of the first shops to take advantage of that option when it took delivery of the new version in March 2011. Branham says using the toolpath engine is as simple as selecting it from a drop-down menu in CAMWorks’ roughing tab. Its greatest benefit is toolpath efficiency. “There is no wasted motion,” he notes. “For example, when you calculate an internal corner, there is a whole lot of math involved. CAMWorks with VoluMill does most of that math for you. That saves an average of 50 per cent on machining time for these features.” As another example, he cites a hypothetical job that involves removing a large amount of material from a part’s exterior. Another system, he says, might require creating numerous tool paths to ‘step in’ the tool and avoid overload. VoluMill, in contrast, maintains a constant radial load on the tool and never deviates. “If you tell it 20-thousandths stepover, it will do that every time,” he adds. In all, VoluMill has increased material removal rates enough to achieve cycle time reductions ranging to 80 per cent in some cases. The shop reports that tool life has also improved, sometimes by as much as 500 per cent. Coupling these benefits with time-saving features of CAMWorks has helped the shop improve efficiency and attract new work, including parts it wouldn’t otherwise have been able to make, Schaeper adds. Courtesy: MMS magazine