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Pushing the Boundaries of Multi-Axis Machining

By CNC Software Inc. (Mastercam) Contributed Article
Jeremy Fritchy, FK Instrument manufacturing engineer, analyzes Mastercam’s OptiRest toolpath, which performs rest milling operations to remove remaining material with optimized roughing motion. (All images provided by CNC Software)

A decade ago, when multi-axis machining was still in its nascent manufacturing stages, FK Instrument Co. (FKI) in Clearwater, Fla., was already pushing the boundaries of precision. While its competitors measured tolerances in fractions of an inch, FKI worked in microns. With ITAR registration and AS9100 and ISO 9001:2015 certifications under its belt, FKI primarily serves the aerospace and defense (A&D) sector.

At its headquarters, FKI’s team of 85 skilled professionals—including a dozen programmers—are distributed across three buildings that span 75,000 sq ft. The machine shop houses an arsenal of 50 CNC machines that can handle complex A&D components.

FKI can also produce its own fixtures and tooling, including Swiss units and traditional lathes, as well as three- and five-axis horizontal mills. Setting the bar for precision are two Yasda PX30i “ultra-tolerance” five-axis units, each equipped with 320-tool magazines and 33-pallet pools.

The newest addition to FKI’s shop is a Yasda YBM 8T-TT. This high-speed, trunnion-style, five-axis horizontal machining center has a circularity tolerance of 2.8µm during simultaneous five-axis conical machining. It operates in tandem with a Fastems 18-pallet automation system.

Software Support

FKI has always been ahead of the curve, with multi-axis capabilities dating back 15 years. All of its CNC mill, wire, lathe and multi-axis units are powered by Mastercam CAD/CAM software from CNC Software Inc. in Tolland, Conn. And FKI’s certified reseller, Camtech Engineering Services LLC in Port Orange, Fla., ensures the CAM suite and programming team remain up to date via a range of training, on-site and virtual troubleshooting, post-processor development and rollout updates.

Camtech adapted its support to suit FKI’s needs. “Camtech’s service and support were centered around the realization that demanding projects with tight deadlines may necessitate collaborative problem-solving to find the most effective solutions,” explains Ben Mund, channel marketing manager for CNC Software. “Such partnerships benefit both the Mastercam user by ensuring timely project delivery and the Mastercam representative by uncovering innovative ways to use the software that can benefit the broader Mastercam community.”

Jeremy Fritchy, a manufacturing engineer at FKI with more than 30 years of experience in the machining industry, relies heavily on this software. When customers provide part models, one of his first steps is to import it into the CAD/CAM system, either directly or via a third-party CAD program. There, he adjusts the file, if necessary, before applying toolpaths.

Many of the parts he handles fall under the category of new product implementation (NPI) parts, a special type of prototype at FKI. NPI parts involve creating a few initial pieces, subjecting them to various tests, addressing issues that arise and repeating the process. Frequently, NPI parts demand several iterations before they reach finalization.

Most of these are what Fritchy calls “ultra-critical” parts with extraordinarily tight tolerances that can only be achieved in the most advanced multi-axis shops. As an example, he describes a recent NPI: The 1" (25.4-mm)-cubed part serves as a mounting plate for a semiconductor made from titanium. Although only five units are produced in each run, they require intricate machining and meticulous forethought. Several features on the mounting plate necessitate a 3-micron profile tolerance.

Because of the part’s size and the tight tolerances, tooling options were limited. Mastercam’s unique Dynamic Motion technology continuously assesses the machining process, adjusting angles, feeds and speeds as needed to maintain optimal cutting. Dynamic toolpaths are particularly advantageous for FKI, Fritchy says, because they minimize stepovers and maximize the flute length of the cutting tool. This facilitates better heat distribution and uniform tool wear, enabling the use of smaller tools than conventional machining would allow.

Engaged Evolution

Mastercam’s Dynamic Motion engine represents the evolution of tool engagement control. In traditional machining, it was common to use a 50% stepover rule. This changed with the introduction of radial chip thinning, which boosted feedrates and material removal in straight line cuts. The logical progression was to extend this idea to the entire tool path, not just straight lines. With advancements in processing power and the development of in-house algorithms at Mastercam, the time was right to turn this concept into reality.

Using zero-point fixturing helps FK Instrument industrialize its production runs and reduce setup times.

Mastercam’s proprietary engine utilizes lookahead knowledge to continuously adapt the cutter path, maintaining a consistent load on the tool. Initially designed for 2D milling such as contouring and pocketing, the Dynamic Motion engine has evolved to encompass 3D roughing and even turning. The result is significantly faster cutting, longer tool life and reduced machine stress.

FKI has particularly benefited from Dynamic OptiRough with 3D High-Speed Raster. This roughing approach, powered by Dynamic Motion technology, employs deep step-downs and stock awareness. It is invaluable when machining fragile or challenging metals, which FKI often does.

Cutting cycle time is advantageous when running high-priority parts such as those earmarked for the U.S. Department of Defense. While lead times vary, delivering parts past deadline is unthinkable, Fritchy stresses. One such recent project involved a computer housing body that was about two inches long, 1.5” wide and 0.5” thick (51 x 38 x 13 mm). Fritchy made it in a series of operations: CNC machined roughing, anodizing and finishing. “With the new update to the software, I was able to get it all done so much faster,” he says. The updated interface keeps all machine settings and definitions under one tab for ease of access.

Although he hasn’t been able to test run all of the updates yet, Fritchy is especially excited about the Unified Multiaxis Toolpath. In the new unified toolpath, “Morph,” “Parallel,” “Along Curve” and “Project Curve” commands are all easily accessed in one location. As a result, he will be able to experiment with different approaches without having to create new toolpaths each time.

Machining a carrier body from 6061 aluminum using more than 660 Mastercam toolpaths. Material was machined from a 200-pound block of aluminum. Final part weight: 14 pounds.

“I want to use that on any five-axis application where I need better control of my surface finishes,” Fritchy says. “Sometimes we have contour surfaces that are spheres with radii, and it’s important to control the bends. Without those advanced toolpaths in the software, I don’t think a lot of these parts would even be possible. Just being able to use previous cuts as stock for continuing tools allows better control of your toolpaths.”

Commitment to Precision

The FKI team manually inputs information—and personal annotations—for custom-made tooling and toolholders into the program, but they can also download tool libraries from outside manufacturers as needed. Fritchy also records the feeds and speeds for different materials and machines in his library. “We all share a library and every one of us can see which tools are in which machine,” he says. The data is critical to working as a team, particularly with cutting-edge machines that each have identical stage tooling.

While the CAD/CAM package can be paired with third-party verification add-ons, Fritchy often relies on in-system Verify, Backplot and Simulation tools. “It’s the easiest way for us to verify that our toolpaths are achieving what we are looking for,” he says. The functions check for possible collisions, gouges, air cuts and programming mistakes. If found, these issues are immediately brought to the attention of the programmer for fixing.

FKI’s commitment to precision extends to thorough part verification before and after machining. A pair of quality labs in separate buildings are constantly at work, with three Zeiss coordinate measuring machines (CMMs) ensuring that every part is free from inaccuracies. After this initial check, parts proceed to probing and scanning tools equipped for contact probing, passive and active contact scanning, and non-contact optical scanning with confocal white light and 1x camera sensors. Such meticulous quality control measures make it possible for FKI to maintain AS9102 compliance for first articles, according to the partners.

“Establishing enduring partnerships like the one with FKI creates an ideal environment for productive two-way communication and mutual growth,” says Mastercam’s Mund.

“As companies like FKI expand, their demands on programming tools increase. Mastercam receives feedback from users through their local representatives about these evolving needs. This feedback loop allows users to benefit from improvements based on their input. It is essential to collect such feedback from a diverse range of shops, and FKI, known for tackling some of the most demanding work, is a prime example of what compels Mastercam to continuously adapt and improve alongside its customers.”

For more information on Mastercam, visit or call (860) 875-5006. For more information on FKI, visit or call (727) 461-6060.

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