The seamless connection between design files and nest creation simplifies production
September 7, 2012
It sounds like a no-brainer in electronically connected world, but shops don't have the ability to integrate their 3-D modeling capabilities with nest creation. As more shops jump into 3-D modeling with the goal of decreasing turnaround time for jobs, they are looking at a more formal connection between the design and production world.
The idea of connectivity just doesn’t connect with some people. Many companies have shop management software that isn’t integrated with shop floor production controls, and management really doesn’t have a real-time picture of which fabrications are being shipped or what’s in process to be shipped. Other fab shops don’t see the need to have enterprise software that seamlessly translates order entries into job orders for the shop floor, electing instead to take their chances by entering orders manually and then inputting the same information into scheduling.
Maybe they are spooked by horror stories associated with software integration. Maybe they remember the days when you couldn’t run two software programs on the same computer because they would fight over the same temp files. Maybe they are comfortable with the way things are.
Other fabricators, meanwhile, recognize that lack of connectivity as a disconnect with what’s needed to compete in today’s market. That is evident with two metal fabricators who have found success connecting their 3-D modeling software with their nesting software (see Figure 1).
Donnie Wilson and Jeff Cantrell combined their welding and manufacturing skills with their oilfield service experience to create a drum oil skimmer back in 1989. The duo established Elastec in southern Illinois at that time to make and market the product and haven’t looked back since.
Today Elastec/American Marine is a leading manufacturer of pollution control equipment, with a specialization in oil recovery. In fact, its boom products were used as part of controlled burnoffs from the Deepwater Horizon oil rig explosion in the Gulf of Mexico in 2010. The company has more than 140 employees and four manufacturing and warehousing facilities around Carmi, Ill., and another facility in Cocoa, Fla.
The company also made headlines late last year, but this time they weren’t related to a new oil disaster. Beating out more than 350 competitors, Elastec won the $1 million top prize for designing the most effective oil-recovery device as part of the Wendy Schmidt Oil Cleanup X CHALLENGE. Spurred on by frustration over the ineffectiveness of typical oil-recovery equipment used during the 2010 oil spill, the X PRIZE Foundation launched a competition to find a better way, and Wendy Schmidt, president of the Schmidt Family Foundation and wife of Google executive Eric Schmidt, stepped forward to offer the financial reward.
Elastec won with an oil-recovery device design that features giant grooved discs that provide a large amount of surface area and channels for oil to adhere to. It is capable of skimming oil at a rate three times greater than technology that was once the primary means of oil recovery (see Figure 2). More specifically, the new skimmer design is able to collect more than 4,670 gallons per minute, while limiting the amount of water that is collected at the same time to 10.5 percent of the recovered volume.
From a manufacturing standpoint, Elastec has to have its pollution-recovery equipment ready for any emergency that may occur. That means it routinely has to have product in inventory because an oil-recovery equipment company doesn’t have the luxury of lead-time when it comes to these emergencies. The company, however, also has to be able to respond like a job shop, because people always are requesting tweaks to existing designs, and new prototypes are always under development.
“Sometimes you just never know where these ideas are going to come from,” said Jeff Elliott, an Elastec engineer. “That’s where we put a lot of our time and energy.”
Elastec fabricates components for its pollution-recovery devices out of carbon and stainless steel and aluminum, in thicknesses from 16 gauge to 0.5 in., although it has done work up to 0.75 in. in aluminum in the recent past. Its main cutting tool is a plasma cutting table from C&G Systems, Lake Zurich, Ill., and Striker Systems software is used to nest parts and run the plasma cutting table.
On the design side, the company has been using AutoDesk® Inventor® for almost a decade. Working in the world of 3-D modeling is a welcome luxury, Elliott said.
“When I go back to use 2-D now, it’s a nightmare,” he said.
The nesting software has a plug-in called PARTshare® that keeps Elastec’s designers out of the 2-D environment for the most part. Instead of having to open up individual parts of an assembly file, save them as flat files, and then import them into the programming software, this software interface automates all of the steps. The part designer hits a button within the 3-D modeling software, and the parts within the assembly are saved individually as flat files and placed within the Striker Systems library, ready to be fed into a nest when production scheduling calls for it. As long as the 3-D model has been saved as “sheet metal,” the software interface easily converts the parts to 2-D files. (PARTshare is capable of working not only with AutoDesk, but also with other modeling programs such as SolidWorks® and Solid Edge®.)
On the surface, this seems like a time savings of several seconds. However, if a designer is working with a very complex assembly file, such as the back end of a dump truck, that file could contain hundreds of components that have to be extracted individually and saved as flat files. Such an undertaking literally could take a day.
Elastec, admittedly, isn’t working with assemblies that contain that many parts, but they certainly are more complex than simple electrical boxes. So when it comes time to produce a prototype, Elastec can rely on PARTshare to create 2-D files and corresponding nests quickly, so the engineering staff doesn’t disrupt production on the shop floor.
“You can just take the whole thing and throw it in there as an assembly, and it will break your parts down and list them. So you can cut out the parts for an assembly and prototype it in a short time,” Elliott said.
Most of the time Elastec runs one shift, so the prototyping team uses the plasma cutting table after most of the shop floor crew has left for the day. But when they need to squeeze prototype part cutting in during the main shift, they know they can quickly create the nest and minimize production disruption.
The PARTshare interface also offers the capability to quickly create nests for regularly scheduled cutting on the plasma table. Making nests for an extended period of cutting may take several minutes, but it’s a marked improvement over how this might have been done. Even as it relates to part characteristics such as material thickness, if the “sheet metal style” has been saved correctly within the 3-D modeling software, the nesting software has no problem assigning the flattened parts to the appropriately sized sheet metal blank.
“You can nest a week’s worth of work in a matter of an hour,” Elliott said.
The Elastec engineer added that the software interface also streamlines the outsourcing relationship with subcontractors that handle services such as laser cutting. They can quickly create the flat file and then just save it as a DXF file for the laser cutting programming software. Instead of a multistep process, it’s a simple two-step one.
Elliott said that they have had fewer worries about outsourcing, however, because their plasma table’s cutting capabilities have been fine-tuned. By altering the kerf and cutting speed within the Striker Systems CAM software, the operator can cut parts to tight tolerances that otherwise might be hard to hold with the plasma torch just blazing through the cut patterns.
“What it amounts to is you have the right software and the right backing, so it doesn’t take half a dozen draftsmen to do what you need to do,” Elliott said. “If everything works seamlessly together, and you actually can go out and spend the money on the software that cuts your job down to just minutes instead of hours and days, then in the long run, you are coming out ahead.”
Summit Truck Bodies is a manufacturer people are likely familiar with but don’t really know it. It’s in the transportation business to some extent, but the Wathena, Kan.-based manufacturing company doesn’t make cars for the general public; it manufactures service truck bodies.
Most drivers probably have seen one of Summit’s end products on the side of the road or in a parking lot. The company fabricates the service bodies that go on heavy-duty truck chassis (see Figure 3). These include customized bodies with multiple compartment and door configurations and with various options attached, such as compressors, cranes, power sources, and welders.
The 100-employee company regularly cuts and punches aluminum and galvannealed, galvanized, carbon, and stainless steels in thicknesses from 18 ga. to 0.75 in. The material thickness and end-part function determine if it will be punched on a Murata press or cut on a 4,000-W Amada laser cutting machine.
Engineering Manager Jim Harris said Summit Truck Bodies has been very busy this year, with an ever-growing backlog of work. The company is running a 50-hour workweek at its Kansas plant, but the laser cutting machine is running a full second shift as well, prepping parts for the next shift’s assembly needs.
“It wouldn’t be uncommon for us to take a basic truck from start to finish—or from laser to out the door—in about two weeks,” Harris said. “A more complicated truck may take four to six weeks.”
Product flows as you might expect. The turret punch or the laser cutting machine produces blanks in a fabrication zone at one end of the plant, and those parts are sent to the forming area where the press brakes are. From there the parts go to welding, then to pretreatment and painting, and finally to assembly.
The company has been using AutoDesk Inventor to model its truck bodies for about seven years. It has been using Striker Systems software to run and nest on its turret punch press for about four years. It uses another CAM package to operate and nest on the laser cutting machine.
As companies gear up to stay on top of product delivery dates in the face of a growing backlog, they can attest that it’s easy to lose focus on the small production details that ultimately could cost them thousands of dollars at the end of the year. After all, more than one metal fabricator has had to shut down even though it always had work coming in the door.
PARTshare has helped Summit Truck Bodies to avoid costly rework.
“Previously we’d have to generate the flat patterns for individual parts and that introduced the chance for human error because, as we built up a list to make a full assembly, you might get the wrong quantity for an individual part of the assembly,” Harris said. “Whereas with the direct route [of having the software interface create the 2-D files from the 3-D model], we’ve reduced one more step where human error can jump into the system.”
Mike Boggs, sales manager, Striker Systems, said such a program is useful because it ensures consistency in the flattened part files .
“Because you do have in all of these solid modeling packages settings that can be set on individual workstations, they can potentially alter the outcome that you have in the flat part. With the implementation of PARTshare, it forces a review of that to make sure everything is set consistently across all systems so that you can get consistent flat parts,” Boggs said.
Just as it did for Elastec, the software interface is saving Summit Truck Bodies several hours per week because it doesn’t have to generate flat patterns to create the nests. Production scheduling is coordinated through enterprise resources planning software.
“It also introduces some cost savings because I can try a model, drop it right in the nesting software, and see how much material I’m going to use,” Harris said. “If it’s close to going over a certain number of sheets, I can bring it back, make a small design change, and perhaps save an entire sheet of steel having to hit the punch.”
This type of software interface between the 3-D modeling package and the nesting software also works for the laser cutting machine. However, when a programmer wants to call up a nest on a PC using the other software, it must have Inventor running in the background. The Striker Systems product does not require the two software programs to be installed on the same PC.
Harris added that the manufacturing team generally relies on the nests that the software creates, but every now and then programmers will create a nest to use up a remnant. When that situation occurs, the software simplifies making those small tweaks.
In the end, the Summit Truck Bodies manufacturing team understands that anything that helps to expedite production without threatening quality is a worthwhile tool.
“If you can eliminate the places where error can creep into your system, it’s going to run that much better,” Harris said.
That’s a connection that no metal fabricator can deny.
It’s a fact of life in the metal fabricating world: Not all software packages play nicely with each other.
Unless a company has managed to stock the entire shop floor with equipment from one particular machine tool builder, it likely has had to contend with the headaches of using shop management or nesting software, for instance, that is unable to communicate directly with a machine’s proprietary operational software.
All is not lost, however, according to Mike Boggs, sales manager for Striker Systems. Software developers can create a means to extract file information for the nesting software; attach an XML data tag, which has information such as material type and thickness; and present it in a generic way so that it can be used by the proprietary machine programming software.
Unfortunately, it takes time to develop customized code such as that. That’s why it’s important to understand just how any new software package might interact with existing software in place at a metal fabricating company.
“We’ve seen more and more people implementing the software [that translates 3-D models into flat-pattern files for the nesting software] and seeing the benefits,” Boggs said. “But now they are starting to realize that in those situations where they can’t use the software, they have a bottleneck.”