Data file translation woes: A failure to communicate

It may well be that we live and work in the computer age, but the challenges facing mold designers transferring data files continue to be daunting. Some moldmakers have found a way around the problem.

In an OEM’s perfect world, its mold manufacturers would have every type of software available, be fluent in each, and understand their operation. In reality, there are so many different types of software that it’s impossible to have them all.

“One customer demanded all vendors use their format—Catia,” says Kerry Smith, engineering account manager for Industrial Molds Group (Rockford, IL). “We do not have Catia and a seat of the software is quite expensive. If we did have Catia, we could then take their file in and work directly with that, and they wouldn’t have to convert it to a Step or IGES file, which would be a convenience for them. But we design in Pro/E and work with different data types from our customers, and that creates problems because Pro/E likes some software programs better than others. Pro/E does not like Catia due to the way the software is structured.”

Dave Rawlings, sales engineer for Mo-Tech Corp. (Oakdale, MN), says the biggest problem is the large number of CAD software programs on the market. “While there has been some reduction in the number of programs in the past 10 years due to consolidation in that industry—and that’s helped a bit—unfortunately there’s still a large number of products out there that don’t talk to each other,” Rawlings explains.

Mo-Tech has a seat of Pro/E that is used primarily for translations. For designing molds and all programming, Mo-Tech does everything in 3D with Unigraphics, including all the company’s mold bases and pocketing. “It’s all done in solid models with programming offline,” Rawlings says.

Both Rawlings and Smith agree that even some of the translation programs are lacking in capabilities. “IGES is not a very robust format and a lot of data is lost,” says Rawlings. “Bigger programs such as Catia are extremely difficult to translate cleanly with IGES.”

Smith explains that when customers make an IGES or Step file for their part design, it “flavors” that file, and often causes gaps in the part or missing surfaces. “The larger surfaces usually come across okay but where the surfaces meet—where there is a soft edge—those can fail. We have to manipulate the customer’s part file in our CAD and try to recreate those edges and eliminate the gaps before it goes to production,” says Smith. “The accuracy of our cutting depends upon the accuracy of the file output. It’s easy to put out a data file with low accuracy, but then it takes more time on our end to work with it. In order to cut steel from that file we have to make sure there are no gaps in the file. The quality of the data is critical.”

Currently, one of Industrial Molds’ engineers is working on a job in which the CAD model is extremely difficult to bring into the Pro/E tool design program. “Primarily it’s surface and fillet issues,” says Smith. “The engineer has been working on this job for three days just trying to get a part model that’s workable. In our fast-paced world, many part designers think that once something is in the CAD file, it’s complete and you start machining steel. This engineering change job was quoted at two weeks and we’re still trying to get the file compatible with Pro/E.”

Jerry Seidelman, sales and marketing manager for Tech Mold Inc. (Tempe, AZ), says there can be problems in data file transfer even if both parties are using the same software. At Tech Mold, the entire shop is driven off the electronic model; engineering, programming, manufacturing, and even inspection is driven off the solid model, Seidelman explains. “That means the quality of the solid model is critical,” he stresses. “It’s how models are created—the architecture used for creating the models—that can sometimes make it difficult to work with a particular file. Modifying the models can be a pain because they’ve been created in a different way, making them difficult to change.”

Sometimes data is lost because different versions of the same software are being used. For example, you can’t transfer a program from AutoCad 2000 into AutoCad 2010 since the older version of the software is no longer supported. Because most companies continually upgrade their software, moldmakers and their OEM customers need to be upgrading as well.

What to do?
Moldmakers agree that one solution to the problems associated with data file transfer is educating OEM engineers that use the various software programs about the translation issues. “Many [part designers] don’t realize they can’t send you their native file,” says Rawlings. “The biggest issues are just dealing with designers that don’t understand what constitutes good molding characteristics of a part, such as draft or adding radii. It’s rare that we get a 3D model in the door for a part that is moldable.”

One of the toughest things for moldmakers when quoting a job is estimating how long data translation will take. “It’s the great unknown,” says Smith, “because we don’t know how well it will translate into our tool design program. We’ve spent as much as a week transferring files. Once you get the file solid, you have to put in the drafts, etc. to make the part moldable. It’s difficult on our end to convince customers of the severity of the problems we have with part files.”

Robert Earnhardt , president of Superior Tooling Inc. (Wake Forest, NC), seems to have a solution that works for his company. “For everything we need, we ask for it to be sent in a Step or Parasolid [Siemens] file. We haven’t had problems because most CAD systems can put out data in one of those two formats,” says Earnhardt. “There’s a design tree created in solid models, and we don’t get the design tree, but our engineers can work with it anyway.”

 Ideally, there would be standardization in the industry, notes Rawlings. “If everybody would continue to work toward creating a universal transfer system such as Parasolid, we’d be much better off—the whole industry would be better off,” he adds. “But you’ll never get these CAD software people to sit down and work toward a singular translation system.” —Clare Goldsberry