March 2008 Edition

LASER CUTTING

'Impossible?' No Such Word at Liberty Steel

Efficiency and flexibility, not only in its performance as a company, but in the machines it uses, lets a company specializing in prototyping stay nimble

Liberty Steel Fabrication Inc. was used to making the difficult seem easy. When faced with creating a part using a press brake that most machine manufacturers said was impossible, it found a source and machine to do it.

Liberty Steel, founded in 1998, has a 23,500 ft² facility in St. Joseph, MO, that handles more than 800 different orders per month with an average lead-time of eight days per job. Prototypes are the majority of its projects. It specializes in medical, transportation, automotive, food, and aerospace work, while remaining flexible and responsive without compromising efficiency. Owner and founder Andrew Gantenbein seeks technology that cuts set-up time while expanding company capabilities.

A laser system wasn't cutting it for Liberty [pun intended]. It had too much downtime for the company to remain agile. Gantenbein replaced it with a Bystar 4 kW laser cutter with shuttle table. He chose the unit from Bystronic Inc., Hauppauge, NY, because of ease of maintenance.

With other manufacturers, maintaining the laser resonator meant sending the original back to the manufacturer and receiving a rebuilt unit, usually not the one that was returned.

"This meant that the resonator returned after maintenance was not the resonator purchased with the system," he said. "It's a rebuild from another customer."

However, the Bystronic resonator could be maintained at his facility.

Following the laser's installation, Liberty Steel was cutting 1/4" aluminum in eight to 10-hour shifts around-the-clock to keep up with demand. Despite aluminum's reflectivity, Liberty ran the job lights-out for years.

"We loaded the machine and let the pallet changer cycle once during the night," Gantenbein said. "We unloaded and reloaded the tables each morning, and the machine would continue processing. Our productivity was amazing."

Processing materials from 0.001" to 1/2" stainless steel and up to 3/8" aluminum, Liberty became so productive that local competitors began outsourcing to the company.

"One neighbor outsourced almost all of its laser work to us," Gantenbein said. "Eventually they purchased a 4 kW, 5'×10' laser system from another manufacturer hoping to eliminate the need to outsource. But, even after it purchased a second and third laser, it was still outsourcing work to us."

He said that it was not until the company purchased a fourth laser cutting machine that the level of outsourcing decreased.

"It seems our Bystar system can do the work of four lasers of the same size and wattage from another manufacturer," he said.

Gantenbein attributes the difference to technology.

"Between the cutting speed, lights-out capability, and the software's part nesting technology, this machine has given us a serious advantage over the competition."

Enhanced Capabilities

A new challenge appeared in a complex part for the food industry. The part was manufactured overseas with a four-month turnaround time. This was too long for the customer, so it asked if Liberty could do the job. Accepting it meant Liberty Steel needed a laser cutter, but also a press brake that could form 0.029" thick, waffle-textured stainless steel into an outward-sloping circular shape. Gantenbein visited press brake manufacturers with the part, but was told that it couldn't be done.

"All I heard was 'impossible,' " he said, "until I visited Bystronic. When I showed the product manager the part, he said it wouldn't be a
problem using the Beyeler PR Series press brake."

Gantenbein purchased the 150-ton press brake, but the demands didn't stop there.

Only a 2D print of the part was available, so Liberty had to create a prototype. Engineers made a composite-material model that was laser-scanned. They imported the information into CAD, and ported the CAD model into Bysoft. The software created a flat profile for laser cutting and press brake programming, including suggestions for necessary tooling. After the profile was cut on the laser, it was transferred to the press brake. Bybend, a specialized software bending module, established the required degree of bending to complete the part.

"The cutting and bending were seamless," Gantenbein said. "We didn't have to scrap a single piece. In less than five hours the part was finished, and it was perfect the very first time."

The part had such tight tolerances it could be micro-laser welded with 0.015" filler wire. When manufactured offshore, the lower tolerances meant the piece had to be soldered – imparting trace amounts of tin and lead. The tighter tolerances that let it be welded instead of soldered meant the part could be considered medical grade.

Natural Progression

Waterjet cutting was the next logical step for Liberty after it mastered laser cutting. It added a Byjet 4022 waterjet with shuttle table.

"There's nothing we can't cut," Gantenbein said. "We can do any project, material thickness, type, sheet size, or job quantity.

"We're a strategic solutions provider. We specialize in prototype runs less than five parts," he said. "The waterjet gives us the ability to manage anything."

The Byjet's shuttle table has also meant that the machine can process certain jobs lights-out. Liberty processed up to four sheets of stacked material on each table. When the machine was finished with one table, it switched to the other and continued cutting without operator intervention.

After acquiring the waterjet, a customer requested cuts in 5" titanium plate. It was the machine's first job, and it cut at 0.25 ipm.

The waterjet was also used to cut geometric shapes from a 5'×10' slab of 2" copper.

"This was a project we knew we could handle. Although it was expensive customer-supplied material, processing was smooth and easy. The Byjet processed the copper at 1 ipm."

Waterjet processing costs are similar to the laser cutting system at Liberty. The company installed a closed-loop water recycling system that let it process and reuse the system's water.

"Maintenance is scheduled and predictable," Gantenbein said. "In overall productivity, maintenance on the system has been negligible. Systems that are reliable, that run 24/7 when needed, and are without complications have made a world of difference here." Bystronic Inc.

Visit www.rsleads.com/803mn-203 for more information

What do you think?
Will the information in this article increase efficiency or save time, money, or effort? Let us know by e-mail from our website at www.ModernApplicationsNews.com or e-mail the editor at pnofel@nelsonpub.com.