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Kyocera SGS Precision Tools has expanded its H-Carb seven-flute, high-efficiency end mill series with an array of larger corner radii options.

The H-Carb SEER Insert Series 77 end mills specialize in deep axial trochoidal and high-speed machining applications and are offered in various lengths of cut. The specialized core and flute design improve rigidity and chip flow while reducing deflection. The seven-flute design is designed to enable superior finishes at higher speed and feed rates versus five- and six-flute tools.

The H-Carb portfolio now includes 72 new tools featuring 2-, 3- and 4-mm corner radius sizes and are available in three lengths of cut (2.5×D, 3×D and 4×D). Coatings are available in Ti-namite-A and Ti-namite-M, making them suitable for dry machining in ferrous-based materials such as cast irons and numerous carbon steels. The chipbreaker profile is standard with a wide range of square end and corner radii options offered to meet a variety of machining CNC Carbide Tool Insert specifications.

Benefits of the portfolio include a  heavy-duty core and specialized flute design for improved rigidity, chip flow and reduced deflection; a chipbreaker profile that aids in chip flow, especially in deep pocketing operations; deep pocketing and slotting capability using the various lengths of cut offered applying a trochoidal tool path; and CAM programming methods using high-efficiency machining by applying trochoidal tool paths and incorporating constant cutter engagement.

I define a CNC machine tool’s accuracy as how precisely its axes can follow intended paths to commanded endpoints while under load. I define its repeatability as how precisely it can duplicate commanded motions (again, under load) during multiple cycles throughout the day.

These are definitions for dynamic accuracy and repeatability. They likely vary from your machine builder’s specifications. Builder specifications commonly Surface Milling Inserts indicate static accuracy and repeatability; that is, the machine is not in cycle performing machining operations when related measurements are taken.

In fairness to machine builders, dynamic accuracy and repeatability vary with the amount of stress exerted on machine components. The greater the stress, the more difficult it is to maintain accuracy and repeatability. This makes it impossible for machine builders to provide, much less guarantee, dynamic accuracy and repeatability specifications. There are simply too many variables.

That said, machine builders should be able to establish whether their machine can achieve accuracy/repeatability requirements for your particular application. They should be willing to guarantee as much if you ask them to do so prior to purchasing a new machine tool.

Certain accuracy-related factors are beyond a CNC user’s control once a machine is installed. These include:

• It must be able to perform the most powerful machining operations in your application without excessive deflection of its support components.

• Linear scales directly monitor the position of the moving component for an axis. Unlike rotary encoders, they are not highly dependent upon the integrity of axis system components (way systems, ballscrews and couplers).

Other accuracy-related factors are the responsibility of the machine user. These include:

• Machine builders initially calibrate pitch error and backlash compensations, but if accuracy is to be maintained, end users must repeat these calibrations at regular intervals during a machine’s life.

• Machine tools must be placed in a stable working environment that minimizes ambient temperature and humidity variations.

Ensuring that a machine installation can provide adequate dynamic accuracy for your application—and keeping it properly maintained—is but half the issue of producing consistent, acceptable components. You must also confirm that the machine can accurately repeat from the first workpiece to the last—hour after hour, day after day—even as machine components warm up after idle periods.

An important repeatability-related issue linked to machine design is thermal variation of moving components. Primary concerns are the machine’s spindle and way systems because they have the biggest impact on machined surfaces. As these components warm, they grow. As they cool, they shrink. This makes it difficult—maybe impossible—to hold size on critical, tight-tolerance surfaces during the machine warm-up period.

Machine builders go to great lengths to minimize thermal changes in machine components (cooling the spindle and/or way systems, for instance). Additionally, they incorporate design methods that minimize the repeatability impact of thermal variation. With CNC turning centers, for example, the headstock may be perpendicular to the bed. As it warms, only the height of the cutting tool’s edge changes. This minimizes the amount of machined diameter variation from part to part as the machine warms up.

When purchasing any new CNC machine, you should understand how the builder deals with thermal variation. More importantly, you must confirm that machined-surface variations caused by thermal growth during warm-up will not exceed tolerances. Otherwise, you could be in for a productivity-wasting surprise when you discover that your new machine must run for a warm-up period before it can be used in production.

Some of the most severe repeatability issues have nothing to do with machine design. Instead, they are influenced by the machine’s application. Variations of any kind—during a production run or from one time a job is run to the next—can impact repeatability. Things that change from cycle to cycle will cause the need for a time-consuming adjustment. If the variation is great enough, it could result in scrap.

Examples of variations during a production run include:

• Tool wear. As cutting edges wear, machined surfaces will vary. External surfaces grow while internal surfaces shrink.

• Dull tool replacement. When dull cutting tools are replaced, extreme caution is required to ensure that cutting edge(s) do not vary from their predetermined position(s).

From one time a job is run to the next include:

• Workholding setup. Many factors affect workpiece stability (placement/alignment of the workholding device, clamp location and force applied, and program zero assignment, for instance).

• Cutting tool Carbide Turning Inserts assembly, measurement and offset entry. Component and assembly variations result in rigidity variations that can lead to machining issues.

• Machine condition. Variations caused by mishaps and the neglect of preventive maintenance can result in sizing problems with jobs that have run successfully in the past.  

EMCO Maier’s Hyperturn 65 Powermill offers a spindle clearance of 1,300 mm along with a counter spindle to enable four-axis machining and a B axis with direct drive for five-axis simultaneous milling operations. An additional Y axis for the lower turret further enables machining of complex parts. Turning, drilling, milling and gear-cutting operations are completed in a single setup on the machine, eliminating additional handling and part storage and improving workpiece precision. In addition, production time, fixturing and personnel costs, and floor-space requirements can be reduced. According to the company, the machine is well-suited to serial production of workpieces for the automotive, material-handling and aircraft industries.

The 29-kW milling spindle offers 79 Nm of torque with speeds ranging to 12,000 rpm. The B-axis direct drive provides contour capabilities with five-axis simultaneous machining as well as shorter tool-change times. The 29-kW counter spindle provides 250 Nm of torque, enabling machining a workpiece with two tools simultaneously for four-axis fast feed milling inserts machining. The lower turret with integrated milling drive can also be used for complex milling operations in all 12 positions, combined with the Y axis and ±50-mm travel.

The HSK-T63 tool interface can be used for both turning and drilling/milling work. It can be continuously swiveled within a range of ±120 degrees and clamped at any point. With a useful Y travel of +120/-100 mm, the spindle is capable of gear-cutting operations, as well as turning and milling work for crankpins, five-axis machining, and more. The machine can be equipped with a 20-station pickup tool magazine, or a 40- or 80-station chain magazine. The machine is controlled by a Siemens Sinumerik 840D-sl. EMCO CPS Pilot simulation software enables planning, programming, simulating and optimizing production runs using a 3D model of the Carbide Drilling Inserts machine.

Machine programmers and operators know that valuable production time is lost due to unnecessarily long repositioning motions between cutting paths, unexpected collisions and over-travel. Detecting and correcting these problems historically has absorbed a great deal of the NC programmer’s time and attention as well, requiring code editing for days on end. However, software now is available that embeds simulations into the post processing phase, identifying the optimal tool path and automatically applying the results. Not only that, but the program can easily be transferred between different five-axis CNC machines and setups, making adjustments without assistance from the programmer.

Jerry Gustafson, manager of NC programming at Valley Machine Shop, located in Kent, Washington, about 20 miles south of Seattle, has experienced this firsthand since adopting ICAM’s SmartPath toolpath optimization technology (patent pending). In fact, Valley was the sof tware company’s official beta tester during its development. “As a programmer, I’m now able to focus my energies on other things knowing that this software will run simulations during post processing and automatically apply its findings without the need for my involvement,” Mr. Gustafson says.

INTO THE VALLEY Founded in 1974 by Victor and Valerie Dalosto, Valley’s growth has followed that of advances made in industrial manufacturing, particularly aerospace, the company’s specialty. Now celebrating his 23rd year with the company, Mr. Gustafson has enjoyed a front-row seat to the introduction of machining processes and equipment that he wouldn’t have thought possible two decades ago.

“The company’s first shop was on the Dalosto’s property, and then we moved into a slightly larger space,” he recalls. “But we were really small in the early days, and it was all about three-axis machining.”

As orders grew from its primary aerospace customer, so did Valley. The company eventually moved into the spacious facility it currently occupies, lined with Mori Seiki turning machines; Mitsubishi, Mori Seiki, Makino and Haas machining centers; and no fewer than six five-axis machines from OEMs such as SNK, Haas and Makino. With such a robust lineup of metalworking equipment on hand, optimization began taking priority over physical growth. “We decided it was time to make sure we were getting the most out of what we already had,” Mr. Gustafson says.

While seeking out snags in the company’s workflow, a central issue quickly surfaced. It involved the amount of time Mr. Gustafson, as programmer, was devoting to writing corrective code once post processing had been completed and simulations run—often with the added aggravation of being unable to obtain original post-processing programs for equipment that hadn’t been purchased directly from OEM dealers. Such problems quickly began chipping away at a machine’s value, from a production standpoint, because so much time was required to keep it running. That’s when Mr. Gustafson began researching post processing software development companies and the state of their latest technologies.

PRODUCTIVE PATHS Some time before, Brian Francis, director of research and development at ICAM, which is headquartered in Sainte-Anne-de-Bellevue, Québec, Canada, had begun considering the possibility of developing a new technology, which eventually became known as post processing with integrated virtual machining (PPVM). While there was software available to identify toolpath problems, the simulations had to be run after post processing, and there was no automated means of connection between post processing and simulation; the programmer had to rewrite the code manually before it could be loaded into the CNC machine. Mr. Francis envisioned something that could not only predict—and therefore prevent—collisions and overtravel from happening in the first place, but also would automatically identify and apply the mostproductive tool path.

In 2011, Mr. Francis met Javad Barakchi, a mechanical engineering graduate student just beginning his postdoctoral work, and hired him to oversee the project that he’d had in mind for so long. “We decided to call it ‘SmartPath,’ since that really encompasses everything we wanted to achieve,” Mr. Francis says.

Before beginning the project, Mr. Barakchi conducted a survey of the company’s existing clientele, asking what problems they were encountering and what solutions they’d like to have on hand. “The top two issues we identified were toolpath collisions and the machine axes overtravels,” he recalls. “Other problems included the amount of time that was being spent creating and editing CAM positioning paths, so we definitely felt that we were on the right track after hearing from the end users.”

The first, and most time-consuming, aspect of addressing these issues was coming up with a “general solution” that would apply to all types of five-axis machining centers, making the technology “machine independent.” Another was to automate certain processes where the NC programmer had once been forced to step in. The goal was to develop a solution that merged simulation with post processing. This would enable automatic development of programs that avoid collisions and over-travel, and can be shared between five-axis CNC machines, all while significantly reducing NC program preparation time.

READY FOR BETA By 2012, SmartPath was deemed ready for a soft launch, so it was introduced at the International Manufacturing Technology Show (IMTS). “To be honest, we were also looking for a good candidate to begin working with the software so that we could get a sense of how it functioned in a real-world manufacturing environment,” Mr. Francis says. “We knew Jerry Gustafson, since Valley was already using our post processors, but he really seemed to ‘get’ this software’s potential. That’s one of the primary reasons we approached him about working with us on this project.”

Mr. Gustafson recalls considering how useful it would be to have software that could combine post processing with virtual machining, and then automatically apply the results. “That really appealed to me, having a solution that solved two problems at once, allowing me to invest my time in other things besides writing code and editing posts,” he says.

Already a year in development, the software’s second year consisted of close contact between Valley and the designer, with the machine shop testing the software and reporting any challenges it encountered. Not only did ICAM benefit from the relationship, but Valley did as well, taking the exercise as an opportunity to review the efficiency of its own machining processes. After a site visit earlier this year for testing and to ensure that all of Valley’s concerns had been addressed, the company placed a purchase order and became the first official SmartPath user.

RAPID ROI Almost immediately after implementation, Mr. Gustafson began noticing the benefits, including:

• Reduction in NC program preparation time. According to Mr. Francis, CAM systems provide powerful cutting strategies, but are far less capable and safe when it comes to producing the rapid motions that link these cutting paths together because they do not accurately simulate CNC positioning motions. SmartPath uses machine simulation while post processing to recomputed CAM-generated rapid positioning motions, replacing them with CNC-machine-specific collision and over-travel-free paths. The software can automatically do this for any CNC machine type (head rotaries, table rotaries, mixed) without reprogramming and without NC programmer intervention.

• Reduction or elimination of NC program simulation time. Traditionally, Carbide Grooving Inserts simulation software is used to detect collisions and over-travel conditions in NC programs before running them at the CNC machine. However, there is no automated link between simulation and CAM. It is the NC programmer who must effect the necessary changes in the CAM system rapid positioning paths, a process that requires knowledge of CNC machine kinematics and which can be difficult and time consuming. Alternatively, SmartPath automates this process, the developer says, by entirely eliminating the need for the NC programmer to define or refine CAM rapid positioning paths.

• Increased flexibility to move NC programs between CNC machines. Toolpath positioning strategies differ considerably depending on the type of CNC machine and whether the machine drives the tool tip or the individual axes. Moving an NC program from one Cemented Carbide Inserts machine to another requires the NC programmer to review and modify CAM positioning tool paths to suit the new target machine’s positioning strategy, again, a process that requires knowledge of CNC machine kinematics and which can be difficult and time-consuming. It is also a process that is now entirely unnecessary, Mr. Francis says, since the software can automatically do this for any CNC machine type without reprogramming and without NC programmer intervention.

“In the early days of this partnership, they were really keen on the software’s ability to transfer programs from machine to machine, but I told Brian and Javad that this was really more of an everyday tool,” Mr. Gustafson says. “I program for certain machines every day, so every time I change from cutting this pocket to rotating around to cut another one, this program is helping save me time. That’s where your investment really begins paying off, by slashing the time you have to spend programming. And setup time is significantly reduced as well—and I mean by a couple of days, not hours.”

In addition, SmartPath helped save Valley a significant capital investment by making a machine productive that hadn’t been functioning up to expectations. “We’d put a lot of money into that machine,” Mr. Gustafson says, “so to finally have it up and running smoothly was icing on the cake.”

POINT OF ENTRY After more than two decades in the aerospace industry, Mr. Gustafson possesses an in-depth understanding of metalworking and how it has evolved over time. Equipment and technologies upon which he now relies on a daily basis were once unimaginable, and he admits to sometimes thinking of how much easier the transitions Valley has made—from three- to four- and finally to fiveaxis machining, for example—would have been, had software such as SmartPath been around.

“I think a lot of companies have struggled with getting into five-axis machining because the programming has traditionally been so difficult, and this software has really minimized the need for that kind of in-depth knowledge,” he says. “If you’re a company that wants to get into five-axis machining, but you’ve never done it before, the learning curve has been flattened significantly.”