A cut above the rest

ControlDesign.com

Twenty-two synchronized servo drives in one machine is a huge control challenge. This pioneering machine builder put its reputation on the line and convinced its customer to try a new approach.

By Joe Feeley, Editor in Chief

FOR SOME TIME now, the U.S. Automotive Industry has faced the challenge of increases in raw material prices and rising labor costs. These factors coupled with the tendencies of American car makers to cut prices via factory rebates and incentives, lead directly to a need for more efficient machines to make vendor parts less costly.

A Tier One automotive supplier decided to research and purchase a new fabrication machine that could guarantee higher throughput and reduce product scrap. The supplier brought its “wish list” to Eagle Manufacturing Corp., Shelby Township, Mich., a recognized presence in the design and fabrication of punching, sawing and notching systems for the Automotive industry and other industry segments including aerospace, plastic, rubber, aluminum extrusion and roll forming.

The customer challenged Eagle Manufacturing to develop an innovative inline notch-and-cut-to-length fabrication system that the profile fabrication industry was urgently in need of.

The Time Was Right
In its previous machine control schemes, Eagle incorporated a mix of technologies from different automation manufacturers. With a design that now relied too much on manual changeover, Eagle realized that the time was right to design an improved solution—a solution that would have to incorporate 22 servo axes in one system. Eagle broke new ground with this design--it had never used that many axes on a single machine before.

“We had a labor-intensive design that required a fork lift and operator to move one of four independent punch tools in and out of the machine,” says Eagle Manufacturing president Brent Short. “With our customer demanding faster changeovers and more flexiblity, we had to find a better way.”

Eagle has migrated over the past 40+ years from pneumatic power and controls, to hydraulic systems, and finally, during the past seven or eight years, to servo drives and motors. “We actually have a good hydraulics-based system,” says Short, “but we couldn’t guarantee the level of positioning control required.” He also says that the jump to servos was the catalyst to better machine performance. But this next step was still a whopper.

The new notch-and-cut-to-length fabrication system would be built to fabricate multi-durometer extrusions for automotive window trim components. It would incorporate four independent fabrication stations, any of which could be automatically shuttled into position in five seconds to match achieve the two-door coupe and four-door sedan production run requirements of the car model. In addition, this instant tool change had to be done without requiring a line shutdown or pausing the upstream stations that feed the system.

A FABRICATING LINE LIKE NO OTHER

Eagle Manufacturing took a bold step forward by eliminating the labor-intensive tool changes that hampered thoughput. It took 22 synchronized servos to accomplish the task.

Let’s Talk About It
Integrator Majority Controls, Port Huron, Mich., initially briefed Eagle Manufacturing on its partnership with automation supplier B&R Automation and showed Eagle how it could meet several specific design requirements, including the need to precisely link every motion axis to a high-resolution encoder.

Eagle’s Tier One customer initially requested a Rockwell Automation controller and HMI. However, the servo system was open. Working with a tight space requirement, the complete controls solution, including drives, had to fit a two-door 72-in. enclosure. The job already had been quoted and approved, so the budget was tight and fixed.

The parties then took the next step. They introduced Eagle’s customer to the proposed solution for its new “Eaglematic” machine. Eagle’s customer wanted to review the system design in detail and inspect the proposed new hardware.

ADVERTISEMENT “We had a labor-intensive design that required a fork lift and operator to move one of four independent punch tools in and out of the machine. With our customer demanding faster changeovers and more flexiblity, we had to find a better way."

Short says that once they saw the equipment and realized the capabilities and integration level of the proposed system, the customer reconsidered its requirements and ultimately removed its brand-preference restrictions, agreeing to complete use of the B&R controls that Eagle recommended. The control solution used Ethernet Powerlink for communications between the main controller, a 10.4-in. panel PC and 22 ACOPOS servo drives.