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Donsco Incorporated (Wrightsville, Pennsylvania) produces gray and ductile iron castings. Founded in 1906, Donsco has added capabilities over the years to address the ancillary needs of its customers, including semi-finish and finish machining, painting, coating and assembly, making it a full-service foundry.
At the end of the day, however, the company's core business is still the production of iron castings; without them, there is nothing to machine, paint, coat or assemble. The process of manufacturing iron castings begins with creating a sand mold around a pattern (a physical model of the finished part), removing the pattern and then pouring the mold with molten iron. Once cooled, the sand can be knocked loose, and what is left is a cast-iron part.
The problem is that the artisans who create these patterns aren't available in the numbers that they once were, and as skilled workers retire, there aren't enough replacements to staff the industry. Foundries across the country face this problem as the skilled labor pool diminishes through attrition. The remaining patternmakers are working longer hours trying to keep up, causing longer lead times.
Managers at Donsco realized that they needed to make greater use of the talents of the few remaining patternmakers, and that those workers would have to pass their knowledge on to a new generation of workers. Productivity would also have to be improved. These challenges were taken on by Michael Day, vice president of operations at Donsco, and the company's Belleville plant manager, Chuck Cutshall.
Mr. Day and Mr. Cutshall used computer technology to replicate the abilities of the patternmaker. Instead of having a class-A patternmaker producing patterns from blueprints directly on a machine tool, the new methodology would have the patternmaker create the pattern as a solid model in a computer system. A CAM program is used to create the machine tool's G-code from that model. Then, while machine operators manufacture the pattern, the patternmaker can move on to the next design.
At age 56, Bernie Kyler has been a patternmaker all of his life, but he lacks in-depth computer skills. Don Milliken, a tool design engineer, is only 25, but while he lacks Mr. Kyler's pattern making experience, he is comfortable with computer technology. Teaming them up to spearhead the automation effort seemed like the right prototype for achieving the company's objectives.
After shopping around for CAM software, Mr. Kyler and Mr. Milliken selected GibbsCAM, CNC programming software from Gibbs and Associates (Moorpark, California). According to Mr. Kyler, the GibbsCAM was easy to use, yet powerful enough to handle the myriad of geometries and shape configurations required. The ability of GibbsCAM to read in data from Donsco's existing Solid Edge and Vellum 3D CADD systems would increase productivity by eliminating duplication of effort in re-creating existing geometry.
"Often, I'm able to do in a few hours what used to take as long as 2 weeks," says Mr. Kyler. "Overall productivity improvement on most parts seems to average out to about 80 percent. Our turnaround time has gone from weeks to days."
One of the things that Mr. Kyler likes most about the GibbsCAM is the fact that he can work directly in a solids environment to design patterns, avoiding the painstaking process of wireframe design. "That's how I think when I'm building a pattern," he explains. "I see solid objects in my head, not lines, arcs and splines."
Mr. Milliken views accuracy, not productivity, as the major achievement resulting from the introduction of the GibbsCAM system. "By computerizing these models, we can respond to customer changes more quickly and reliably than ever before," he says. "If a customer calls us up in the middle of production and needs to move a boss or flange on a part, for instance, it's a simple matter in GibbsCAM to change the solid model and then regenerate the toolpath automatically around that change. More often than not, CNC code can be altered and out on the machine tool in a matter of minutes.
"Surface finishes are also greatly improved," Mr. Milliken continues. "GibbsCAM can generate reliable toolpath with a very small stepover on complex surfaces in a very short period of time. Our handwork has been reduced to a minimum, and typically, all we have to do is go over our pattern with an abrasive pad."
By taking a proactive stance, Donsco has managed to recognize an 80 percent increase in productivity in generating patterns. The company has decreased handwork on patterns through improved surface finishes and reduced throughput times by allowing the patternmaker to disseminate his knowledge directly to the machine tools through the CNC code. As an added bonus, tool design engineers now work closely with the patternmakers, allowing patternmakers to adapt new technology more effectively and allowing engineers to absorb the craftsmanship skills from the patternmakers.
"We've managed to exceed our expectations and stay within the budget, and we've recognized ancillary benefits that we didn't even expect," says Mr. Day.blog comments powered by Disqus