One term that has been gaining traction is “reshoring”— the movement of product manufacturing from low-cost production areas such as China back to North America and Western Europe.
Reshoring is being concentrated to high-value goods, such as those that require complex production molds with advanced materials, production capabilities and strict quality control. The argument behind the movement is that the final cost of these products after quality checks, shipping times and repairs (if necessary) offsets the initial low-production cost and margins while affecting time to market.
It remains to be seen whether reshoring becomes more than a trend. But it raises a question: Can producers in high-cost manufacturing parts of the world be competitive without throwing margins out the window? Automation is a big part of this cost equation, to be sure, along with greater reliance on machine tools that standardize many capabilities.
For example, one toolmaker whose specialty is aluminum molds for high-volume automotive parts says machining centers should be versatile and include features and capabilities that meet as many production needs as possible. To be more competitive, machining centers should be less custom in design and capabilities, says Darcy King, vice president of sales and engineering at Unique Tool & Gauge in Windsor, Ont. “The technology needs to go to more automated, faster equipment,” he adds.
Many manufacturers of machining systems are doing this, and production shops that invest in automated equipment are reaping rewards in productivity and cost savings.
One recent example comes from Germany, where Horst Klein GmbH, a small (14 employees) CNC specialist, installed an RXU 1200 machining center from Soltau, Germany-based Röders GmbH, which has North American representation. The RXU 1200 is a 3-axis system (5-axis models are available) with features that are designed to speed production, increase productivity and eliminate the need for cutting complex workpieces on multiple machines.
The Roders RXU 1200 machining center has enabled mold maker Horst Klein to significantly reduce production time of mold halves.
These include a spindle speed of 30,000 rpm, a voluminous machine table (1,300 x 1,100 mm), two magnetic tables that automatically position workpieces and eliminate manual clamping, high-power linear direct drives, high-resolution optical position sensors and internal cooling sensors that thermally stabilize machine components.
The RXU 1200 also features Röders’s Quadroguide Z-axis, which the company says increases cutting rigidity, improves precision, extends tool life and achieves high cutting force. The Quadroguide design has four guide rails on each of the four corners of the Z-axis mechanism — 16 in all. These transmit acceleration and machining forces from the cutter along the Z-axis into the Y-axis, which is firmly connected to the machine frame. This produces a damping effect that increases Z-axis rigidity and reduces inertia, Röders says.
These features attracted Horst Klein to the machine. The company produces molds and dies for various industries and was having problems machining new and refurbished drop-forging dies made of 1.2714 hot work tool steel and hardened to 48 Hrc and averaging 500 x 600 x 350 mm. Roughing of a half-mold workpiece — all that could fit in its machine — was being done on one machining center equipped with large (66-mm) cutters. Pre-finishing and finishing operations were then moved to a second machine that used smaller (3- to 6-mm) ball-milling cutters. The total production time for each piece was 31.5 hr. Even with lights-out production, the one-shift shop could only machine three or four mold halves per week.
Klein installed an RXU 1200 machining center earlier this year and almost immediately saw productivity gains. The rigidity of the machine gave it the speed, precision and versatility to complete roughing, pre-finishing and finishing operations of the drop-forging dies, thus eliminating the need to transfer a workpiece between machines. The size of the RXU 1200 machining table also meant that both mold halves could be machined simultaneously, essentially doubling production rates.
Accuracy, meanwhile, “seldom exceeds more than a few microns,” according to Klein, and this deviation can, in some cases, be reduced by modifying the cutting program.
As a result, Horst Klein has seen total production time for each drop-forging die half decline to 19 hr. Weekly production has so far increased to seven mold halves. The machining shop says it is able to supply molds and dies faster and can add larger-sized jobs and meet tighter deadlines with the system, as well as take on rush jobs due to the increase in productivity.
Roders’s Quadroguide Z-axis design is said to have added rigidity to improve cutting efficiency and speed. Note the two drop-forging tool halves that fit on the large machine table.
