Can a more-or-less traditional moldmaking shop in post-industrial, high-tech Pittsburgh find increased prosperity with some high tech of its own? That was the fundamental question confronting the co-owners of Jatco Machine & Tool Inc., when they realized their 2D and antiquated 3D software for computer-aided manufacturing (CAM) were not “cutting it” anymore.

Jatco’s 2D CAM software worked well for routine mold base and mold component machining but upgrading to a 3D level was cost prohibitive. Their 3D software was one of the first CAM systems available on an affordable UNIX computer, but it dated back to the 1980s.

Unfortunately in recent years the provider had done a poor job of keeping up with current trends in computer operating systems. In particular, their move to solids was not well executed, the roughing routines were not very effective, and tool path verification had to be performed with third-party software.

“Like many small manufacturers who invest years of time and training in a piece of software we found it hard to justify the cost of jumping to a more capable package,” said Rich DeSalle, Jatco co-owner. Early in 2004, however, Jatco began investigating alternatives.

The local EdgeCAM distributor (Roney Software, East Springfield, Penna.) offered a very attractive package deal. After comparing all their options, Jatco finally settled on EdgeCAM. The previous 2D software is still used for simple pockets and drilling. The old 3D package was retired.

At Jatco a large part of making tools for the plastics injection molding processes involves machining graphite or copper EDM electrodes. Using primarily one machine tool, a Mitsui Seiki bed-type vertical machining center with a Fanuc O-M CNC control, Jatco turns out all the electrodes used by four ram-type EDM machines to finish each mold cavity.

The new CAM package, EdgeCAM from Pathtrace Systems, Southfield, Michigan, gave the Jatco programmers real integration with their solids modeling software, SolidWorks. This associativity and connectivity let them handle their complex work much more efficiently. That has meant fewer time-consuming electrodes and a lot more highly productive unattended machining.

Keeping moldmaking in Pittsburgh
The company’s enhanced competitiveness helps keep Jatco from losing mold work to the low-labor-cost countries in the Asian crescent stretching from China to India. Mold shops in these rapidly industrializing countries pose a serious, long-term competitive threat to firms like Jatco. Jatco’s customers—the automotive suppliers—relentlessly seek lower tooling prices in Asia. Jatco itself subcontracts some of its work to offshore partners.

A vital part of Jatco’s mold building process involves the machining of intricate graphite electrodes, dozens of them for each mold. The electrodes detail and finish each mold’s cavity surfaces that mold the customer’s parts. After using EdgeCAM for a year and a half, DeSalle noted that the connectivity of the EdgeCAM Solid Machinist for SolidWorks module, and the power of SolidWorks, allow him and the mold designers the flexibility to design and machine the most complex jobs.

This ability to handle intricacy on short delivery times is developing into a new competitive advantage for Jatco. For example, recently the complicated tooling Jatco builds has been used for automobile control panels and displays. The process involves three related tools—a vacuum forming tool, a trim die and finally the plastic injection mold. A flat decorative film is vacuum formed and die cut to precisely fit the cavity of the injection mold.

The process provides components with durable decorative finishes. These new capabilities for precision CAM programming have helped Jatco win and perform flawlessly on contracts for this three-step insert molding process. Developed by Bayer MaterialScience, (also in Pittsburgh) for decorative trim components, the three-tool process requires that the thin-film part fit smoothly into the injection mold. The three tools share common geometry but with varying shrinkage factors and offsets. They mandate precise programming and machining.

All this programming intricacy is easily handled with EdgeCAM, much of it by modifying offsets from one program to the next. “EdgeCAM’s accurate and reliable toolpaths have increased our confidence in this process,” DeSalle added.

Jatco’s new capabilities impact many other projects as well. “On one recent two-mold project we machined nearly twenty different electrodes,” he continued. This is typical because generally it is not possible to incorporate all of the features of a part into one electrode. In this case, as always, the twenty different electrodes had to be individually machined.
Adding to the complexity of the process is “overburn.” Overburn is the offset distance between the electrode and the finished mold surface that accounts for the spark gap and the orbital in the EDM process. When these features are burned into the mold steel, it is critically important that their electrodes be precisely milled in order to insure that the EDM’ed features fit together exactly as designed to recreate the original part. “This is a major reason for the need for precision in the CNC toolpaths,” said DeSalle.

As with any manufacturing endeavor, a key factor in reducing costs and increasing profitability is the reduction of scrap. Prior to acquiring EdgeCAM, Jatco’s designers would have to check their toolpaths on a third-party software package. This was a time-consuming process that sometimes required several iterations.

“Even worse would be the job of finding a gouge by visually inspecting the problem area on the old CAM software’s graphic depiction on the computer screen,” DeSalle said. “Needless to say, EdgeCAM’s integrated verification feature has greatly simplified the process and virtually eliminated scrap. With EdgeCAM, it’s not so much looking for gouges as it is looking for mistakes that the programmer might have made,” DeSalle added.

The other major problem Jatco faced with its old 3D CAM system was the poor quality of the roughing routines, in particular Z-level roughing. The program worked so poorly that it was generally easier to create 2D roughing programs.

“The big drawback to the 2D roughing approach was that the amount of stock left on the steel was not uniform,” DeSalle said. “Because most of the detail in precision molds is EDM’ed after heat treatment—when the steel is hard—the uneven stock resulted in uneven electrode wear. And that required more electrodes.

“Elimination of 2D roughing reduced the number of electrodes and EDM time as much as 30%, said DeSalle, who does most of the Jatco 3D machine tool programming. He noted that two or perhaps three electrodes now finish a surface or mold detail that previously required three or even four electrodes.

With EdgeCAM’s improved machining capabilities, he pointed out, Jatco can rough and prefinish cavity details to within 0.010 inch to 0.020 inch of the final cavity surfaces. Only that 0.010 to 0.020 inch of stock is left for the EDM machines.

More unattended metalcutting, better roughing
The most obvious result of better verification was Jatco’s ability to increase its unattended machining by about 30%. “Now with verification we are so confident in the accuracy of our programs that we can start a cavity roughing or electrode machining job on a Friday afternoon and come in Monday morning to see it finish up,” DeSalle said. “Because we can trust our cutter data, the entire process is speeded up.”

Nearly all mold shops use unattended machining to some degree. Loading many CNC programs into a direct numerical control (DNC) system keeps machine tools making chips, uninterrupted, for two or three days at a time. This is especially useful for roughing large cavities or molds with multiple cavities as well as for machining graphite.

Unattended machining is less of a CAM software function than the way the DNC system, jobs, machines and cutting-tools are set up, DeSalle pointed out. But without error-free toolpaths, the unattended / DNC production strategy would come to a speedy halt or generate a lot of costly scrap.

DeSalle says that EdgeCAM is also great for more routine work such as prototyping , specials and simpler components because it is easy to reuse previously developed machining strategies. To do this with EdgeCAM, a machining process is captured and converted into a PCI template that can be applied to any new job that is similar. All the tooling selections and approach strategies are in the template but any of them can be modified.

Accommodating Change with CAM

EdgeCAM facilitates this through its associativity with SolidWorks. Anytime the solid model is changed in SolidWorks, EdgeCAM alerts the programmer to the change. The programmer may automatically update toolpaths then and there or do so later, at the user’s discretion.

Asked if he would summarize the benefits Jatco gets from EdgeCAM, DeSalle listed

• Having high confidence in programs, thanks to the built-in toolpath verification, which facilitates high-productivity unattended machining and eliminates scrap due to gouges.



• Being able to more precisely pre-machine cavities, which means far fewer electrodes are needed and much less EDM “burn” time than when cavities were hogged out with 2D roughing.



• Having the ability to machine precise electrodes that guarantee the accurate replication of the customer’s model.