Bridging Gaps: 5-Axis Machining

Lean manufacturing is much more than a buzzword. It is a potent concept that has aided many manufacturers, large and small.

Lean manufacturing involves using processes that have been simplified via advanced technology to produce more with less manpower while continuously improving quality and reducing lead times. The paradox of lean is that when everything has been stripped to the bare essentials to boost productivity, no one has much time left to capture, assimilate and implement the knowledge needed to adopt new labor-saving technologies.

Derek Goodwin, president of manufacturing consultancy Goodwin Manufacturing Group, Morgan Hill, Calif., is out to change this conundrum. The group offers packages of CAM-centric services that bridge the gap between the acquisition of advanced manufacturing systems and fully using their capabilities to boost productivity and reduce costs.

Derek Goodwin (left), president of Goodwin Manufacturing Group, works with Lime Lab Inc. Prototyping Manager Chris Iverson to get a DMG Mori DMU50 5-axis vertical machining center operating near its full potential within weeks of installation.

Goodwin’s team starts by evaluating the business objectives that drive the acquisition of a new technology and how this technology can be integrated with the company’s existing CAM processes.

“CAM is central to managing everything that happens on the shop floor,” he said. “It is the place where we can review our process from beginning to end and get everything right before we start making chips.”

When serving customers, the Goodwin Manufacturing Group is CAM-vendor neutral, striving to take advantage of the strengths of whatever CAM software a customer has. Goodwin and his staff, however, are long-time users of Mastercam from CNC Software Inc., Tolland, Conn.

Essential Steps

Once the business goals have been formulated, Goodwin’s team implements a four-step process:

With Mastercam for SolidWorks, prototypers can do all of their work, including writing and simulating CNC toolpaths, within the SolidWorks programming environment.

With this process, Goodwin said his company can implement technology acquisitions and process improvements in weeks that would take a customer’s internal teams months to complete. One element that moves the process along quickly is knowing the CAM software’s strengths and how they might be applied to bridge gaps that prevent advanced manufacturing systems from operating efficiently.

Manufacturers often fail to adequately address cycle-time reduction because of time constraints, according to Goodwin. This means they are missing out on the interrelated knowledge regarding workpiece materials, workholders, controls, thermal dynamics and cutting tools, which continues to advance. This knowledge can be aggregated to achieve greater material-removal rates than could be conceived of even 5 years ago.

A typical project to reduce cycle time involves determining why a particular part or family of parts consumes the machining time it does, Goodwin explained. Once his team has uncovered the root causes, they implement a new process and provide training, documentation and often a video to show others how to replicate what they did.

In one project involving manufacturing a family of parts on a 5-axis machine, Goodwin’s team reduced the machining cycle from almost 4 hours to 20 minutes. He noted the bulk of this reduction was achieved using Mastercam’s Dynamic Motion technology, which automatically adjusts feeds, speeds and cutting tool entries based on the real-time condition of material ahead of the tool. This avoids burying the tool, allowing a manufacturer to confidently run at the highest feasible mrr and reduce tool wear.

In addition, Goodwin attributed about 20 percent of the cycle-time reduction to developing a custom post-processor to resolve short-distance servo acceleration and deceleration issues that prevented the machine from achieving its inherent high-speed machining capabilities.

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