Expected: 100-Percent Accurate Die Designs
It’s a new era of die design and development at world-renowned Autodie, Grand Rapids, MI, where new ownership is consistently investing in new technology and training. The goal: To advance the company’s future as a leading, global supplier of stamping-die engineering and manufacturing services.
This screen shot from Autodie displays the firm’s manufacturable design for a bodyside die, as well as the tool-path sequence.
At the heart of this resurrection is what company vice president and COO David Darling calls a new concept in die design—manufacturable solids. “We’re zealots in terms of die development and simulation,” says Darling. “We are absolutely committed to providing our die-manufacturing group with 100-percent NC-ready die designs. That means closing the gap between those making our solid models and those preparing them for machining, with the understanding that we expect our die designs to be 100 percent accurate for construction, fastening and machining. Failure to demand this level of accuracy amounts to generating rework and waste.”
Paving the Road to Manufacturable Solids
Technology was, unfortunately, not als a focus at Autodie, Darling admits. In the late 1990s and early part of the new century, management treated technology as a commodity, as opposed to a core part of its business. As did numerous others in the North American automotive-industry supply chain, Autodie also outsourced die making to low-cost countries. “We followed that line of thinking until 2006,” Darling says.
Beginning in 2006, Darling and his engineering team focused on rebuilding the technology literacy within its walls, becoming devoted to controlling the die design and build process from start to finish. By January 2007 it was ready to launch its newly developed process, which begins inhouse with development and simulation. Die faces are delivered to a select group of die-design firms charged with creating designs ready to go directly to NC programming.
“For example,” says Darling, “consider a side-aperture design. If you look at the NC programming file, we’re opening up the same die design in the same software that the designer was working from. You’re calling up that detailed part of the assembly and literally opening up the NC tool pathing work bench. This means we’re machining right to the die design.”
Darling believes that while design itself might only represent 5 to 10 percent of the total cost of a die, it can impact 60 percent of that overall cost. And while he admits that “we’ll never be as inexpensive as a low-cost country,” results of the firm’s extraordinary lean efforts are impressive to say the least:
• Labor hours for die construction reduced by 35 percent;
• High success rate with dies being buyoff-ready at first sample; and
• A 50-percent reduction in engineering-rework time, which, says Darling, “has taken a staggering number of hours out of our process when you’re talking about a shop that averages 500,000 labor hours per year.”
A Healthy Die-Design Standards Manual
Key to making its vision of creating manufacturable solids a reality has been nurturing a supply base of a handful (five or six) design houses committed to working to the Autodie standard and developing the required skills. “We’re very surfacing-intensive right now,” says Darling, “and very particular about the surfaces of each die design so that they can go directly to the mill. That level of skill and commitment is not easy to come by, and within the design software that we use inhouse, we use some very advanced techniques that not all design houses understand. These need to be developed.”
In the beginning of the Autodie transformation, its die-design standards manual comprised just a few pages. Today it’s swelled with content to include more than 165 pages of instructions and examples to teach the design community a new of doing things, to enable machinable solids and avoid any remachining due to collisions and interferences.
“Before we were able to really hone this concept of creating manufacturable solids,” says Darling, “we would spend four to six weeks of CAD/CAM programming to prepare die-design surfaces for machining. That time-consuming and ‘un-lean’ process has been virtually eliminated as we’ve added content to the designs.”
Asked to provide examples of this “added content,” Darling points to Autodie’s proprietary application of exercises such as trim-post expansion, press compensation and radius reduction. “Not only have we eliminated that additional four to six weeks of surfacing we used to perform in order to prepare a die design for NC programming, but we also made time to perform these extra exercises,” he says.
Darling also notes that Autodie designs now are “laced with features and identifiers that help automate 3D programming in Catia. Learning to do design in this can streamline the process required to develop a line of dies that once might have required 200 hr. of NC programming down to just 30 hr.”
Much of the lean programming at Autodie comes by virtue of the firm’s relationship with Fiat/Chrysler. “This has allowed us access to tool benches inside of our CAD that most companies would never know even existed or that would be cost prohibitive,” says Darling. “In addition, the programming is all associative, so that should a die design change—during tryout, for example—you’re not breaking all of the links and having to start over. Cutter paths are permanently linked to the surfaces they’re cutting, so if the surfaces change so do the cutter paths.”
More Lean, to Focus on the Long-Term Vision
Other lean die-development efforts shine at Autodie. For example, Darling describes the firm’s use of starter blocks that contain features and identifiers to provide designers a good starting point and help ensure that they will develop dies that meet internal standards.
“For example,” Darling says, “when a designer begins to develop a new die, he accesses pull-down menus in the software that we’ve customized to prevent use of blocks not typically stocked by our steel suppliers. And then within these starter blocks, we limit the selection of screws and dowels to what we have decided to stock. This prevents a designer from specifying some random counterbore depth in the block and then wastefully calling out a matching screw that only adds to our inventory requirements. Instead, the designer specifies screws and dowels that we’ve predetermined to keep in stock.”
The journey to lean, efficient die development and assembly has been challenging yet extremely rewarding, Darling summarizes. “And it’s come thanks to a team of engineers and shop employees committed to working through some intensive struggles,” he says. “Not to mention the commitment of our suppliers to accept our standards and immerse their employees in our training.” It also has led to a machining-technology evolution the company could never have envisioned just 5 short years ago, when its inventory of CNC equipment largely was comprised of machines installed in the mid-1980s.
“In 2006, the big elephant in the room was,” continues Darling, “if we plan to modernize the facility and increase cutting speed by, say a factor of five to 10 times, we had better be sure that what’s going onto the mills is perfect. And that’s where we’ve made great strides. Our big fear was if we were to modernize the shop without this upfront improvement, making mistakes at 1 m/min. would be nothing compared to the severity of making mistakes at 15 m/min. All we’d be doing is making a lot of scrap, very quickly.”
Now the company is comfortable knowing that upgrading its CNC equipment, in concert with improving the accuracy and reliability of its development process, will fuel its continued growth in terms of its customer base, capacity, and revenues and profitability.
“Early in 2011 we announced a 2-yr. capital plan to invest $24 million in new CNC equipment,” shares Darling, “and we’re well on our to making that happen. Among our new additions are three 3.5- by 6-m bridge mills equipped with 20,000-RPM heads and that cut at 15 m/min., and two mid-sized horizontal machining centers also rated to cut at 15 m/min., with spindle speeds of 20,000 RPM.“After it’s all said and done, by the end of this year, if we’re as fast and accurate as I believe we can be, we expect to be able to compete abroad and ship dies offshore.” MF
Related Enterprise Zones: Tool & Die
There are no comments posted at this time.