Case Study From: 5/1/2016 Modern Machine Shop, Edited by Emily Probst ,
From day one, 5th Axis Inc.’s business strategy has been to take advantage of the most advanced software, equipment and technologies available so it could competitively enter demanding niche markets like aerospace, medical and other challenging high-tech industries. However, during the company’s entry into five-axis machining, co-founders Steve Grangetto and Chris Taylor realized their CAM software had major shortcomings—machining collisions were common, and they weren’t able to realize the full potential of their machine tools. Using Hypermill from Open Mind Technologies AG of Wessling, Germany, the company achieves faster run times, better surface finishes and overall better quality.
Eleven years ago, Mr. Grangetto and Mr. Taylor recognized that five-axis machining would give their new San Diego, California-based company a competitive advantage. Today, the company offers complex machining, along with its own line of fifth-axis workholding products including vises, fixtures and adapters that complement a broad spectrum of CNC machines. In fact, this product line is now a substantial part of its business. The shop floor is lined with high-end three and five-axis machining centers from Germany, Switzerland and Japan. All of the machines are programmed with Hypermill, and they clearly demonstrate the company’s commitment to taking advantage of advanced technology. However, it wasn’t always this way.
Business grew dramatically during the company’s first three years. To meet the growing demand for complex, five-axis machining, 5th Axis purchased a new high-performance five-axis machine to accompany its original Haas machine. However, during programming, the company realized the shortcomings of its existing, mainstream CAM software. Along with unexpected machining collisions, the company couldn’t fully utilize the speed, capabilities and potential of its new high-end machine. That’s when Mr. Grangetto and Mr. Taylor decided to give Hypermill a try.
According to Mr. Taylor, they demoed Hypermill on a complicated five-axis part that was giving them fits. They were very impressed by the efficient tool paths, reliable collision avoidance and how seamlessly the software integrated into SolidWorks. “The demo clinched the deal, and we have been successful using Hypermill ever since,” he says.
With Hypermill software in place, the company started buying more high-end equipment. The new machines included Mikron HSM 400Us, Hermle C 30 Us, Grob G350 mills and a couple of Okuma MB-5000H horizontal machining centers. 5th Axis takes advantage of its high-speed, five-axis machining centers programmed with Hypermill to manufacture a wide range of precision parts, including turbine impellers that cannot be made efficiently any other way. This machine-software pairing delivers part precision and time-saving benefits.
For instance, five-axis machining greatly improves part precision by eliminating alignment errors that are introduced in standard machining when a part is removed and refixtured in another orientation. It is also extremely time-efficient, because most or all of the work is performed in a single setup with no delays while waiting for an operator to unload, reload and reposition the part.
The software also provides time-saving benefits by enabling Jesse Norton, director of manufacturing and senior programmer, to simulate not only the part in the fixture, but the tool, the toolholder, the spindle and the entire machine envelope itself.
According to Alan Levine, managing director of Open Mind’s U.S. subsidiary, located in Needham, Massachusetts, the Hypermill calculation confidently monitors the cutting tool assembly, toolholder, spindle, workpiece and fixture to provide a collision-free tool path. Collision avoidance is also included in the toolpath calculation when possible to further increase assurance. Machine simulation is then used as a final check of the machine tool components to make sure that the machine does not collide with itself. Mr. Norton concurs. Stepping through the tool path to watch it remove material and verify that it clears the machine without any collisions is a valuable time-saver. “I do not have to walk out to the shop floor and manually look inside a machine with coolant flowing to check clearances,” he says.
Another benefit of the CAM solution is the Hypermill Maxx Machining roughing module, which is designed to create extremely efficient roughing tool paths due to careful control of material removal and use of smooth trochoidal toolpath motion where possible. Trochoidal tool paths enable a higher feed rate without overloading the cutter or causing premature tool wear, because they take smooth, gradual “nibbles” out of the material, Mr. Levine says. They allow feed rates to be set for the best cutting conditions, rather than the most challenging cut, such as a corner condition. By controlling the amount of volume or the angle of the cutter’s engagement, the cutter can loop into a corner. The Maxx Machining roughing module extends tool life, and machining time is reduced by 30 to 75 percent by maintaining a constant chip load, Mr. Levine says. 5th Axis can use Hypermill Maxx Machining on materials ranging from aluminum to hard materials like Inconel because its high-speed machines are fast enough to keep up with the rapid toolpath motion that is generated. “The bottom line is that using Hypermill Maxx Machining results in super-efficient and fast tool paths,” Mr. Norton says.
Mr. Taylor says that Open Mind’s support is one of the things that separates the company from other CAM software vendors. In fact, the company takes complete ownership of postprocessor development. “That’s a really big deal,” he says. “Especially with five-axis machining, where an accurate post becomes extremely critical in avoiding crashes. The machine does exactly what we simulate on the computer screen.”
Open Mind uses internal experts to develop postprocessors, which it considers to be a core technology of the company. The customized postprocessors have configurable parameters that enable users to control their particular environments. This means that the core mathematics and the basic structure of the post are created and locked down by Open Mind, but 5th Axis can change certain parameters, which influence the locked portion.
According to Mr. Levine, “Some companies give the customer a tool kit and the ability to build their own post, but those guys are not there to write postprocessors; they are there to cut metal. Also, writing the entire postprocessor is too much for the original equipment manufacturer that has to ensure compatibility with various CAM software products. An alternative approach is to give the customer no control, but then they would have to call back to the service supplier to make custom changes. Our combination of locked and open is not entirely common, and we believe it gives customers the best of both worlds.”
The high-quality tool paths, advanced CAM software capabilities, postprocessor support and skilled technical support give 5th Axis the confidence to take on ever more challenging jobs that require programming complex parts, Mr. Taylor says. “With Open Mind’s help, we never burn money getting stuck on a job. Their contribution has been a really big part of the growth of our business.”
To view the full article, please visit http://www.mmsonline.com/articles/cam-software-helps-shop-gain-machining-efficiencies