Working the process

March 1, 2001
It means improving manufacturing operations through skillful in-house retrofitting with the right control.

It means improving manufacturing operations through skillful in-house retrofitting with the right control.

Over the years, Boeing Wichita Facilities has bolstered its in-house resources to continually improve manufacturing processes and machine productivity. It's referred to as working the process, which involves managing the various aspects of retrofitting and upgrading existing machines. Personnel from the production shops and NC programming to those in facilities retrofit and facilities maintenance all contribute to the approach.

The 13.2-million-ft 2 Wichita facility is where all the major structural airframe elements of the Boeing 737 jetliner are manufactured, as well as engine nacelles and other major components for the rest of Boeing's commercial fleet. The facility houses a number of multiple-axis milling machines and other exotic machine tools for producing large, complex components and multi-element structures.

According to Manager, Facilities Retrofit, Ed Fenn, retrofitting these machines with new controls, drives, and other technologies is a well-known path to productivity at Boeing. When a machine's internals and mechanical interfaces begin to significantly fade, his team steps in and remakes the machine.

"Everything is upgraded," explains Fenn. "We install new ducting, wiring, magnetics, controls, cabinets, drives, motors, operator functions, and the operator interface." His team also works over all the mechanical aspects of the machine tool as well, installing bearings, resurfacing/refacing ways and guides, and installing new bearings and ballscrews. "Virtually, we only re-use the casting or shell," says Fenn.

But all these reworked and rebuilt mechanics must be paired with a capable control. Fenn says the right control makes refurbished machines easier to use and easier and faster to program. In addition, it helps the machines compute part-design data quicker, accept and execute toolpath instructions swiftly and efficiently, and adapt to changing conditions during manufacturing.

About six years ago, Fenn and his team found the 840D, a then-new control made by Siemens Energy & Automation, Elk Grove Village, Ill. The Siemens control had been engineered with access to the NC kernel and developed to offer users the flexibility, modularity, and architectural openness needed to adapt not only to a given machine, but also to meet demanding design, engineering, and manufacturing process requirements.

"Because our parts are so large," says Fenn, "we were looking for controls that could quickly process the complex transformations that occur as these components are pitched and rolled to be machined." The Siemens control fit the bill, and thus, Boeing became one of the first manufacturers in the country to use it.

Among the first machines the Wichita Division's Facilities Retrofit team retrofitted with the control was a machine installed in 1995. At the time, this was only the second 840D in the country. Since then, Boeing has fitted a variety of machines with this control technology, including milling machines, profile mills, automated riveting tools, jig bores, multi-axis skin mills, and a laser-cutting machine. The control's open architecture and adaptability to each tool type's functional parameters has brought Wichita closer to standardizing control platforms. It has also helped the organization narrow the variety of controls and suppliers to a more manageable number.

For Boeing, adapting its machines to changing production requirements, whether from a functional standpoint or from a design/engineering data orientation, is now more of a software-based, plug-and-play exercise rather than a costly hardware exchange. "Vendor support is very important to us," says Fenn, "but when all we generally have to do is select software or other control elements from that supplier's standard offerings — and not have to develop anything on our own — that makes our job a lot easier."

Fenn says that the installation of the new control has contributed to both process and operator improvements. He points out that the modularity and upgradeability of this type of control not only lets Boeing retrofit the machines to tackle today's applications but those of tomorrow as well. A tomorrow, he adds, that may include greater overall controls standardization, networked control communication, and faster and more direct levels of engineering and design-data processing.

Fenn also says the retrofit machine tools are generally running better and more efficiently: "We have been able to increase feedrates and improve stability." In particular, he points to the usefulness of the control's 5-axis transformation (tool-tip) function and the adaptive aspects of the controls. "On a profile mill we're finishing up, we installed a 10,000-rpm spindle, and we're looking at the adaptive part of the control to monitor spindle load and heat migration — all of which improve feedrate as a result."

Another employee that has witnessed the progression of control technologies is 15-year veteran and NC Programmer Bob Mitchell. He's used his experience to help the company "work the process" as well. From his perspective, first as a machinist and then as a parts programmer, it's often both the control and its supplier's support that have the greatest impact on how well and how fast new machine tools, and retrofitted or reworked machine tools, can be integrated into Boeing's production environment.

"Process improvement has become part of every day life at Boeing," says Mitchell. "Quite often these process improvements bring technical challenges for personnel. I try to make everything so transparent to the operator that he can maintain his focus on getting quality parts done."

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