VMC Shortens Setup Time For Machining Complex Dies

Dave Rose, the vice president and systems manager of Die-Tron, Inc. (Wyoming, Michigan) is accustomed to dealing with automotive-industry customers who demand efficient dies to make complex parts in as few hits as possible. However, complex parts require complex dies, often with a great deal of off-angle work. Consequently, the lengthy setup times and multiple machining passes were inefficient.

A supplier for the automotive industry, Die-Tron designs and constructs progressive, line and transfer dies for sheet metal stamping at its 41,000-square-foot facility.

Nearly a third of all of the dies the company produces require some sort of off-angle work. To construct these dies, the company says it usually relied on sine plates mounted to existing VMCs.

“Sine plates are appropriate for simple setups,” notes Mr. Rose. “When dealing with compound angles, however, they simply fall below expectations. In addition to being cumbersome, the plates are sometimes nearly impossible to clamp when dealing with very steep angles.”

Mr. Rose continues to say that, most importantly, sine plates do not provide the rigid setup that would normally be required to make deep, accurate cuts. Because of this lack of rigidity, the company had no choice but to make multiple passes on the dies. On many occasions, the machine had to make at least three passes, which, Die-Tron says, wasted time and money and caused extra wear on the machines.

The company’s initial thought was to investigate two-axis compound tables. Although such tables represent a good solution for many applications, they were not cost-efficient in Die-Tron’s case.

Die-Tron realized that a VMC with shopfloor programming and the capability to import DXF files from CAD files would offer more control over the process. Already familiar with Hurco Companies, Inc. (Indianapolis, Indiana), the company purchased a Hurco BMC30.

With this purchase, the company gained the capability to send CAD drawings from a PC directly to the machine for programming, a process that proved to be 20 to 30 percent faster than off-line programming and downloading. The company says it experienced an added bonus—a reduction in leadtimes.

A year later, Die-Tron says it took into account the flexibility of the Hurco control when it decided to purchase a VMX50 to handle 2D work, detailing and additional 3D machining. At this juncture, Mr. Rose made the decision to purchase the newly-introduced VTXU, a five-axis machining center from Hurco after exploring potential solutions. The machine is about the size of a medium to large vertical machining center and incorporates a large work envelope, says the manufacturer. The table measures 23.6" by 19.7", with XYZ axes of 31.5", 27.5" and 20", respectively.

The operator of the new machining center at Die-Tron has been using existing Hurco VMCs, and notes that learning to program and operate the VTXU has been straightforward. Die-Tron is also able to use its CAD system to its full potential while saving programming time by exporting multi-sided DXF files to the UltiMax control.

Using conventional sine plate setups, dies produced at Die-Tron could easily comprise 50 to 60 percent of the total machining time for a complex die set. With the VTXU, setup times have been reduced—in many cases, by days. According to the company, the system reduces setup costs and provides the needed rigidity and accuracy while maintaining throughput and surface finish.

By adding machines with intuitive controls to achieve short lead-times, the company says it is thriving in a dynamic market.