Machining Madness

Moldmaking Technology 08/08

Rising labor costs, the demand for less finishing time, quicker turnaround time, and improved surface finished have all been driving the tremendous advances that have been made in the machining industry these past 10 years. Where does it go in 10 more?

Industry Changes
According to Okuma America Corporation (Charlotte, NC) COO and President Larry Schwartz, the changes that have occurred in the last decade go beyond 10 years-to 15 or more. “Quite frankly, we saw a lot of manufacturers moving offshore looking for lower cost dies and molds for the industry back then,” he recalls. “For some time, the qualified finished die or mold with the technology that had been available was very labor intensive, and the level of expertise that existed in the United States also was dwindling at the same time. Though there was a fair enough amount of developing technology during that period of time mostly around the EDM, wire EDM technology and ECM (electrical chemical machining); these also were very costly. The issue was that almost all of the dies or molds needed a great deal of handwork to achieve the finishes, shapes and smoothness of contours that were required to get the product out of those dies or molds to the level of quality that they were looking for.

“During all of those 10+ years, CNC manufacturers probably lost a considerable amount of that business-with exceptions, of course,” Schwartz continues. “I believe that the technology that we have been introducing as an industry as a whole has been seeking ways to minimize the handwork required to make a finished die or mold. To do that there was some sophistication that was desired in the machine tool design and I’ll use the terms of thermo stability or thermo-friendly that would be required to maintain the finishes that would be needed to eliminate hand polishing. The goal has really been to have zero handwork. The question is to what level can one go into metal removal-using today’s technology-to eliminate that. I personally believe that if we have reached it in some areas, but maybe in time we will reach it in all areas. The combination of control technology, servo controls and the whole balance of mechanical devices-along with some developments in spindle designs and characteristics-has created the opportunity to eliminate a lot of handwork and will continue to improve.”

According to Okuma America’s Schwartz, the company has focused on thermo stability and has won numerous awards for designing a very stable, rigid, strong platform. “We have some very special thermo control capabilities where we are making machine position changes automatically based on thermo compensation, and along with that came some additional Super NURBS which dealt with processing speeds,” he states.

“One of the things that I think most people run into when they are doing exotic, elaborate molds or dies is that the amount of data crunching that goes on is unbelievable,” Schwartz continues. “In many cases, the programs are so extensive and so long that many controls have a problem retaining all of that data in their platforms. Therefore, the information is streamed from a major mainframe design computer that is feeding data to the machine tool as it is being consumed. Delays in information and flow can potentially cause issues with getting the transitions and geometry shapes in the speeds that one would like because one just can’t transfer information that fast. I would say that with our new control, its processing speeds have been improved, and with our Super NURBS capability, allow us to move at very rapid rates with very fine, very exotic geometries. Along with thermal stability we have created what we’d say is probably a finished product out of the machine tool with very little, if any, manual polishing or deburring.”

Future Challenges
In a market that clearly is rising to meet the current demands of the industry, what does the future hold for machining manufacturers and suppliers? Schwartz of Okuma America believes the outlook is bright. “As we advance machine control processing speeds, increase solid modeling ability, create a die from its CAD/CAM environment, and download it directly to the machine tool with little or no operator intervention, we will streamline the whole process from the initial product out of a mold to the calculations dealing with what the true mold geometry is based on: shrinkage, materials used, and how do you drive the program using all the SuperNurbs that we have available,” he states. “To really yield from beginning to end a very seamless process of a finished product off of the machine tool, I believe that we will eventually achieve 100 percent of our goals.

“I believe it is well within the next 10 years that computer technology, the servo controls and the onboard computer processing machines speeds of the machine tool will work together to create a truly finished product,” Schwartz continues. “We are investigating the use of higher end chips that go even beyond the finite analysis engineering that would help us achieve our goals in both the collision avoidance technology and in processing speeds to get even finer geometry, faster moves and create a real seamless process from beginning to end. Our ultimate goal is to move at speeds beyond our comprehension right now. So I think we are on the level and stream of continuing our progression of advanced processing speeds to the next level.”