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Precision Machining Ensures Precision Fineblanking

Saturday, July 1, 2017
 

The exacting nature of fineblanking demands precision tooling. To ensure that its tooling makes the grade, Feintool has invested heavily in vertical machining centers.
“Faster, better, lower cost—pick two.” It’s a pervasive phrase expressed across a range of industries and markets, but is it true? According to Christoph Trachsler, CEO of Feintool North America, customers don’t have to make that choice when it comes to Feintool’s fineblanked parts services.

“What matters most at Feintool is reliably delivering precision parts at a competitive cost for our customers,” says Trachsler. “Our customers don’t have to choose between quality, delivery and cost. We are continuously improving processes, from component and tool design, to system engineering and large-scale component production, to deliver greater results across all criteria. It’s how we stay competitive and help our customers succeed.”

With more than 60 years under its belt, Feintool develops fineblanking systems and produces prefinished fineblanked and formed components, and provides technical expertise to support customers with research and development and prototyping. It operates out of facilities in Europe, Japan, China and the United States, with its North American headquarters located in Cincinnati, OH.

The company’s fineblanked parts services provide a cost-effective means for companies to acquire high volumes of extremely precise stamped parts, making Feintool a premium parts supplier to the global automotive and medical industries.

Delivering a high level of repeatable precision is no easy feat, though. Due to the intense pressure of the fineblanking process, tooling used within the presses typically are composed of 64-HRc hardened steel. And according to Beat Andres, Feintool’s operations manager of toolroom and production tooling, identifying a “capable machine for this type of hardmilling” is difficult.

“Many of the tools that we manufacture contain extremely fine, repetitive features, such as small teeth, which require highly repeatable processes within 10 microns of repeatability,” Andres says. “For many years, the only option for us to reach this level of precision in hardened steel was to hand-finish these features using diamond files. It was a long, arduous and exhaustive process that was not repeatable.”

The addition of three vertical machining centers (VMCs) enables Feintool to keep up with increased hardmilling demands. Also, the quality of tooling exiting these VMCs has limited the amount of hand work, according to company officials, reducing the likelihood of human error, decreasing lead times and extending tool life by as much as 40 percent.
Since investing in vertical machining centers (VMCs), V33i models from Makino, the company has been able to reduce handwork by as much as 30 percent, leading to extended tool life, less variability, greater labor efficiency and substantial cost reductions, according to Andres.

Enhancing Tool Quality with Precision VMCs

Feintool’s first investment in high-speed hardmilling occurred in 2008, following a series of collaborative tests developed and conducted alongside the company’s Japanese division. The tests were comprised of 3D models of 64-HRc components featuring fine-tooth features, similar to automotive seat-recliner components submitted by many of its customers. Performance of the V33i exceeded Feintool’s expectations, achieving the desired tolerances and quality while producing the fastest cycle time among all suppliers evaluated, according to Feintool officials.

Designed for long hours of unattended hardmilling, the V33i delivers high-speed machining with high accuracy, efficient chip removal and simple operation, according to Makino officials. Its standard 20,000-rpm spindle features a core-cooling and under-race lubrication system to minimize thermal distortion at high spindle speeds. Additional rigidity is achieved with the integrated construction of the spindle and drive motor, which cuts down on vibration during high-speed operation.

Controlling the impact of machine movement on thermal characteristics reduces temperature impact on the machining process and yields sustainable, long-term, dynamic accuracy. As such, temperature-controlled lubricant is used throughout the machine to minimize thermal growth during cutting, according to Makino officials. Cooled elements such as core-cooled ballscrews, lubricated ball nuts, a servo-motor cooling-jacket system and temperature-controlled passageways all work to provide structural temperature control.

To bring preheattreated-machining capabilities inhouse, Feintool has invested in additional VMCs. The result, according to company officials: quicker turnaround for customers and higher-quality milling.
Since this initial investment in one machine, Feintool’s business has grown substantially, requiring the company to add a third shift to keep up with demand. By 2014, customer demand had reached Feintool’s maximum capacity, which led the company to invest in a second V33i. The tool magazine on this machine was increased from 25 to 60 tools to support greater capacity and redundant tooling for extended, unattended machining operations. Feintool continued its expansion of hardmilling capabilities with the addition of a third V33i in 2015.

Repeatable Toolwork Limits Manual Finishing

“Fineblanking tools require a very fine cutting edge in order to cut sheetmetal accurately during the stamping process, so we often coat finished chamfers with a TiCN coating to increase the tool’s performance,” explains John Castle, senior supervisor of tool maintenance at Feintool. “When it comes to hand-finishing the cutting edge, each toolmaker might have a different method or approach, which increases the likelihood of inaccuracies in the final tool.

“If any inaccuracies are discovered during the stamping process, the tool must be sent back to the toolroom to remove the coating, reradius the cutting edge and add another coat,” he continues. “This adds up to several hours of downtime for our pressroom. The tool quality coming directly out of the V33i machines has limited the amount of handwork, reducing the likelihood of human error and decreasing lead times, and extended the life of our tools by as much as 40 percent.”

Maximizing Investments with Process Optimization

Feintool’s success in adopting high-precision hardmilling capabilities has been based not only on its acquisition of new machine technology but also on the knowledge and experience of the company’s engineers who have become more innovative in their processing techniques. As part of the company’s continuous-improvement initiative, engineers recently took aim at maximizing machine-utilization rates by increasing annual cutting hours on each V33i from 4500 to 6000/yr. By increasing cutting time on the V33i machines by 1500 hours annually, the company was able to achieve necessary production capacity without investing in a fourth VMC.

According to Andres, Feintool engineers are continuously evaluating new process optimizations to get the most out of machine investments, including programming refinements, cutting-tool selection and improved workholding solutions. One example is the recent adoption of magnetic worksholding. With previous clamping methods, Feintool was limited in the number of tools that it could machine in a single setup. By switching to magnetic workholding, engineers now can maximize space within the work envelope to optimize productivity.

“Once we adopted magnetic workholding and began performing longer runtime setups, we were able to get even more value and return from our V33i machines,” says Castle. “It enabled us to fully take advantage of the machines’ rigidity, thermal-control features, broken-tool sensors and expanded tool changers. Today, we reliably run setups for upward of 12 hr. of continuous cutting with small-diameter endmills, maintaining 10-micron repeatability throughout.”

Additional Investment Cuts Costs and Lead Times

In addition to its advancements in hardmilling processes, Feintool also has made significant investments in its preheattreated-machining capabilities through the acquisition of three Makino PS95 VMCs in 2014.

Prior to these investments, Feintool had been outsourcing most of its preheattreated machining processes. Some preheattreated machining had been processed inhouse on a set of older mills that struggled to handle the forces necessary to perform heavier cutting operations. To reduce lead times, decrease costs and gain more control over the tool-making process, Feintool decided to invest in internal machining capabilities.

“The PS95 machines are workhorses that do an exceptional job of heavy cutting, and in a pinch can even support some of our finishing processes in hardened steel,” says Andres. “Through these acquisitions, we’ve been able to eliminate $500,000 each year in outsourcing, enabling us to pay off all three machines in just one year.”

Today, Feintool’s preheattreated-machining processes are performed faster and with better quality, according to company officials. This performance has enabled the company to not only reduce lead times for customers but also expedite prototyping processes to help customers get products into market faster.

Continuous-Improvement Culture Drives Successes

Considering the pursuit of continual improvement as essential to the company’s long-term competitiveness, Feintool’s leadership and its engineering team share a number of aggressive goals to further improve the quality, delivery and cost of its fineblanking-parts services.

One of Feintool’s short-term goals involves evaluating processing enhancements to reduce or eliminate long-runtime machine processes, such as jig grinding and EDM. The company believes that it can save a significant amount of time and investment by replacing these processes with precision milling.

“At this time, there are still many types of processes that just can’t be milled; however, the precision of the Makino equipment allows us to minimize the requirements of these processes for shorter lead times and lower costs,” says Andres. “To date, we’ve been able to reduce sinker-EDM processes by approximately 30 percent and wire-EDM processes by roughly 10 percent. And there’s more opportunity for further improvement.”

Increased tooling output resulting from Feintool’s milling investments also have put a strain on the company’s existing jig-grinding capacity. Rather than invest in a second jig-grinding machine, the company is evaluating ways that it can use the V33i machines for some jig-grinding processes.

“To properly serve a high-volume, high-precision market such as automotive, flexible and reliable equipment is essential,” says Trachsler. “To not deliver is not an option. Our investments in this precision vertical-machining equipment have supported us in adapting to changes in part complexities, tolerance requirements and delivery times. No matter what challenge comes our way, Feintool is prepared to deliver parts faster, better and at a lower cost than the competition.” MF

Article supplied by Makino Inc., Mason, OH; 513/573-7200, www.makino.com.

 

See also: Feintool US Operations, Inc., Makino Die/Mold Technologies

Related Enterprise Zones: Other Processes


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