Page 35 - MetalForming January 2015
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 “to keep up with demands from our customers.” Tolerances, he says, often are specified at ±0.05 mm on stamped parts.
The Onus Falls to Programming
The newest NTC machine joins four CO2-laser five-axis cutting machines on the Accu-Rite floor, all primarily used to trim prototype stamped parts. The shop processes mostly high- strength steels (some advanced high- strength steels such as dual-phase alloys) to 3⁄8 in. thick. Lately, though, notes company president Kirko Mick- ovski, the firm also has been stamping and cutting aluminum, for frame com- ponents—“a perfect fit for the new fiber-laser system,” Mickovski notes. “The fiber-laser machine cuts alu- minum stampings up to four times faster than our CO2 laser machines, and cuts twice as fast on steel.”
With that much cutting speed at the ready, part of the responsibility for moving work quickly through the shop falls to the laser-programming func- tion. And Loudon and Mickovski couldn’t be more pleased with the pro- gramming solution they invested in several years ago—CAD/CAM software from German-based Tebis (with U.S. operations in Troy, MI).
Tebis software, known better for its functionality related to CNC machin- ing, also features a CAM module that drives five-axis laser cutting. Loaded with unique and carefully engineered design capabilities aimed at this tricky application, the software can stream- line the cutting process while providing pinpoint accuracy, as well as provide reliable and efficient collision avoid- ance. It gets clear nods of approval from Accu-Rite management. The seal of approval:
“We trust Tebis with our millions of dollars invested in our state-of-the- art laser-cutting equipment,” says Mickovski.
Less Air Time, More Run Time
Among the noted features in the Tebis laser-cutting CAM module, as noted by Accu-Rite programmer Mike
The newest star on the Accu-Rite shop floor is this five-axis 3D laser-cutting machine, with a work envelope of 177 by 45 by 20 in. and equipped with a 2-kW fiber laser.
Winkler: With just a few mouse clicks, programming moves from the CAD part model to cutting-fixture design (with supporting-rib geometry includ- ed), and on to cut-path formulation. The software considers cutting-machine and cutting-head kinematics and geometry to eliminate collision haz- ards, while also minimizing major rota- tional movements. Winkler employs the software to program all five of the firm’s 3D laser-cutting machines; machine data—physical dimensions as well as cutting-process capabilities —is contained within the Tebis database.
Winkler also notes that the CAM software minimizes laser-head approach and retract movements, “while ensuring the head isn’t spin- ning excessively,” he says. “We’re min- imizing ‘air time’ and optimizing cut- ting time.”
With programming and cutting time optimized, quick turnaround to cus- tomers becomes less of a worry, say Mickovski and Loudon.
“We don’t use kirksite stamping
tools, we use steel, because our lot sizes are larger than other types of proto- type runs,” says Loudon. “This is because seating parts are safety related. Our part runs are relative large (300 to 400 parts is typical), requiring opti- mum efficiency from the laser-cutting process.”
“We recently completed a package of 140 part numbers,” adds Mickovski. “We ran 60,000 parts, and had the job programmed, through tool develop- ment and stamping, and then through the laser-cutting department and on to shipping in just 6 weeks.”
Huge Time Savings
With upgrades in collision avoid- ance and other features added to Tebis via recent software updates, program- ming is faster than ever—“maybe 30 percent faster than it was several years ago,” says Winkler, “and the process is more efficient. I’m confident that the programs developed in the office, offline, will run the first time on the shop floor. That means we’re not going back and forth from programming to production to fine-tune the lasers. This way, the cutting machines can work on the next job, making money, rather than waiting for program tweaks.”
Winkler says that he can program some of the shop’s simpler parts in just 15 min., and complex parts take only an hour or so of programming time.
Out on the floor, Accu-Rite laser- machine operators trust that Winkler’s programs will run correctly, the first time. “In the past,” says Winkler, “they used to dry-run every job with the cut- ting head retracted to a safe position, to ensure the programs were sound, and then make adjustments as needed. They no longer have to perform that wasteful step, which represents a huge time savings—probably 30 min. on every job.”
Should the operator on the floor, in that rare instance, need to make any modifications to the NC program at the machine, Winkler notes that those modifications can easily be reversed back into the NC job via its relatively simple editing functions.
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