Versatility, Cost Savings with In-House Tool Grinding

Acutec Precision Aerospace supplies critical machined components and subassemblies to OEMs and their suppliers in commercial aircraft, defense, aerospace, and power generation markets – products that range from vibration damping and rotor components to engine, fuel system and air control, hydraulic actuation, avionics, landing gear and braking, rod ends, bearing and metal seals. Its locations in Meadville and Saegertown, Penn., as well as St. Stephen, S.C., perform CNC machining, EDM, metal finishing, welding, and minor assembly with nearly 300 machine tools and other equipment.

But Acutec had a problem maintaining a reliable supply of precision-ground carbide end mills, which are critical to its work.

Chris Wagner, the tool grinding team leader at the Saegertown location, explained: “We were having availability issues with our current cutting tool suppliers on quick-turnaround production order needs, and wanted to bring the work in-house to have better control of quality and lead time.”

Acutec runs most of its tooling production in small batch orders – three to 10 pieces – with an occasional need for up to 150 pieces. It produces form tools, broaches, lollipops, burrs, drills, step drills, reamers, boring bars, trepanning and engraving tools.

In Chicago for IMTS, the Acutec team reviewed the exhibits of various tool grinder suppliers, and was impressed by the ANCA MX7 Linear machine. The MX7 Linear is a versatile CNC tool grinder designed for production grinding and built for high output, high-precision manufacturing. The machine’s 38-kW (51HP) permanent magnet spindle provides high torque at lower RPM, which is ideal for carbide grinding and a wide range of other applications.

Nearly all of Acutec’s tool-grinding work involves solid carbide materials, plus a small percentage involving regrinding of HSS cutting tools. After a demo at ANCA’s location in Wixom, Mich., an MX7 Linear machine was purchased, along with an ANCA FX5 Linear machine with a 19-kW (25 HP) spindle, AR300 robot automation, and laser measurement capability.

The two machines’ performance can be tracked in real time using ANCA’s RedaX process monitoring software

“We run the RN34.1 software package and use three Cimulators to create and save our programs,” Wagner explained. “We have about 30 individual wheel packs preset for both machines to reduce set-up time.” He further noted that most of the jobs at Acutec require special tools, so knowing the ANCA software and machine capabilities have been his team’s biggest advantage.

He credited his previous 12-years’ experience as an applications engineer for ANCA and over 27 years of tool grinding experience with giving him and his team a real leg up on the design of tool geometry, but he noted the software is very intuitive and easy to learn. “The most helpful feature of the ANCA machines is the profile editor. I would say over 70% of the tools we grind utilize it,” Wagner said.

The profile editor allows a designer to visualize and track the grinding wheel and tool profile machining operation for optimal efficiency in machine set-up. Further, it offers the ability to combine multiple tools from a previous set-up into a single, multi-step tool, with easy modifications. As a result, according to Wagner, Acutec has been able to save over 75% of the cost by manufacturing its own tools, versus purchasing from a tool manufacturer or supplier.

“We would often wait 6-10 weeks for a short batch of tools we can now produce next-day or, when needed, same-day, to keep the spindles turning,” he said.

Wagner also highlighted the ANCA special operations manager and scripting functions, which his team uses to create tool-specific operations as well as wizards that assist in creating tool files quickly and consistently.

Regarding in-process tool measurement, Chris Wagner observed that, on longer run orders, Acutec has been able to apply the ANCA FX5 Linear machine’s laser-measurement capabilities to run up to 26 hours of unattended grinding.

Thanks to the ANCA machines, Acutec is able to respond to down machine tools and change geometries on cutters without the long lead-times from outside vendors. This ability to respond to engineering changes has been recognized as a differentiator by customers on R&D collaborations, it added.

Currently, Acutec performs 95% of its regrinding in-house and manufactures that same percentage of its special form tools. A consistent reduction of 50-75% in cost has been realized on its end mills and form cutters, translating into an annual tooling-spend reduction of $200,000, according to the company.

Wagner reported several examples of the ANCA tool grinding – machinery plus software – proving to be highly advantageous to Acutec Precision Aerospace. “For a large project that we started, there were two specific end mills that cost about $100 on average,” he detailed. “We designed a cutter that was not only less expensive but also would outperform the purchased tool.

“The cost for Acutec to manufacture this tool was about $27.00. These two tools alone were enough to purchase a second machine with a projected ROI of one year. And these tool programs can run unattended for up to 25 hours,” he added.

For another big project Wagner recalled that the Acutec team had had created a tool that initially did not work. “There was a lot of chatter,” he explained. “With the ability of our tool grinding department and ANCA machines, we were able to design a new tool that worked much better than expected,” he said, adding … “We were also able to remove another tool from the machining operation.”

According to Acutec, its ROI on the two ANCA machines has been less than three years, and the additional cost savings on equipment and labor have been offset within one year by a reduction in spending with outside vendors for regrinding and special-form tools.