Custom LED fixture maker dials punch presses into high-mix, low-volume shape with SigmaTek software

April 2014 - No matter how fast a punch press is, no matter how many tools are loaded in the turret, it’s the software behind the programming that takes its punch potential to the next level. One manufacturer in Huntington Beach, Calif., sheds light on what it means to maximize punching processes by leveraging punch programming logic and integrating it with its ERP system. Bartco Lighting, a maker of specification-grade LED and fluorescent strip fixtures, keeps its turret punch presses running tight with SigmaNest, the nesting optimization software that’s a household name in nesting parts.

Bartco’s lights go into architectural, commercial, hospitality and residential applications around the world. The fixtures are churned out from one manufacturing plant in California, although the company is represented by agencies across the U.S.

Programming parts for its CNC turret punching machines is integral to Bartco’s operation, says Efren Saenz, Bartco’s director of operations. Almost all of what Bartco manufactures is sheet metal fabricated products—to the tune of 99 percent—all of which need to be punched and formed. More than 95 percent of what the company runs is 20 gauge galvannealed steel sheet. Varying gauges of aluminum or steel comprise the rest.

“SigmaNest is the software that tells our turret punch presses what tools to use and how to punch them,” says Saenz.

Bartco uses Inventor 3-D CAD software by Autodesk to design its sleek light fixtures, which adorn retail stores such as Prada and AT&T, universities like Cornell and Yale, and the offices of eHarmony. The information for part models is used to create a tooling program in SigmaNest. The program then sends instructions to the turret punch press to dial in which punches will be used. That’s a process familiar to just about any manufacturer using SigmaNest for punching.

Founded in 1994, Bartco has two turret punch presses. Both are Muratec by Murata models: the Motorum 2044EZ and Motorum 2048LT.

Illuminating features

As Barto discovered, there are some advanced, unsung features of the SigmaNest program that many users might not expect. “It was simply chosen to do traditional CNC turret punch press programming,” says Saenz. “Recently we were approached by SigmaTek to consider another product to extend the power of SigmaNest by integrating it with our ERP system. This is when we learned we had not yet fully taken advantage of what SigmaNest could do for us.”

That product is SimTrans, which acts as a communication link between Bartco’s business database and SigmaNest. It populates part requirements and material stock into SigmaNest in sequential (customer) order, and reports data associated with the different phases of the process to the business system. In short, it’s a transaction manager, allowing SigmaNest to talk to the company’s ERP system.

Along with SimTrans, Bartco is using mixed nest programming, color offloading and auto tooling. Previously, the company was programming only like-parts on a sheet metal blank.

“If there was extra space, we would normally just run out the sheet. Now, we are using SigmaNest to combine different parts (work orders) on the same blank. Because more than 40 percent of our production work orders are less than 20 pieces, this makes a lot of sense,” says Saenz.

Because Bartco often mixes parts on the same nest, as many companies do, the turret machine operator needs to be able to identify disparate parts and their associated work orders on a nested blank. Onscreen, the color offload function displays a color-coded map of the blank’s layout with each part’s position identified. 

The color offload is crucial for companies that combine work orders and mix parts. “This is obviously important because it allows companies to maximize yield from a given piece of material being cut when they can combine and cut parts that require a similar material type, grade, thickness,” and so on, says Robert Farrell, marketing manager at Cincinnati-based SigmaTek. Additionally, auto tooling capabilities fill a recent void left by an experienced programmer no longer at the company.

Efficiency gains

Bartco is a high-mix, low-volume manufacturer, so mixed nest programming is an inevitable part of daily life in the shop. Until Bartco started taking advantage of SigmaNest’s unique features, it had not harnessed its potential gains in efficiency.

For one, true scrap rates are reduced, says Saenz. “Before mixed nest programming, if there was additional space left on a blank the programmer would just fill the sheet with extra parts.” 

Before taking advantage of SigmaNest’s mixed nest programming, Bartco’s programmer would think he was optimizing a sheet by running additional similar parts beyond those required for a job. Typically those extra parts—perfectly good ones—would end up in the scrap bin either after the run or pulled from stock as excess inventory.

“Now, extra space on a sheet is filled with parts from the next order,” Saenz says. 

Conversely, if extra parts continued with the run, those not needed for an order were put into stock—often not to be used for months, or possibly never again. That created excess dormant inventory, not doing much more than taking up space.

The most common disruption to the metal shop was drop-in requirements for first article runs or expedited orders, according to Saenz. “Previously, a current job needed to be stopped or was leap frogged. Now, we simply create a mixed nest that includes the first-article run or expedited order and run it together with another run. This agility has greatly helped and reduced overtime as well.”

Forming follows punching at Bartco. The fabricator’s experience with SigmaNest translates over to using SigmaBend, the press brake programming software. It allows Bartco to program machines offline (instead of during a production run). This cuts changeover time from one job to the next.

Streamlining business

Bartco’s integration of the SimTrans system is the most recent addition to its operation. In 2012, SigmaTek approached Bartco to consider SimTrans for linking customer orders directly with manufacturing work orders. By integrating SigmaNest with the company’s ERP system, SigmaNest populates process feedback information for work orders and inventory, which is compatible with other systems via SQL tables.

Eventually, with the transaction database, Bartco will be able to add new sheets to stock, and existing ones can be modified if they’re not already in process. Existing orders can be modified or cancelled, too. Even if Bartco needs to add a new undefined part, the geometry is added later in SigmaNest from DXF, DWG, IGES and CDL files. Transaction examples include converting geometries, reordering existing SigmaNest parts and adding stock sheets.

Once SimTrans is adjusted to run seamlessly with SigmaNest and the ERP system, Bartco’s efficiencies will translate into a more streamlined solution to process order information. When software runs that smoothly, Bartco can keep the spotlight on its high-end fixtures. FFJ