STOP LOSING MONEY: FIVE-AXIS TRIMMING

Vacuum forming is a great process for the efficient manufacturing of simple parts without a lot of complex features that need trimming. However, when trimming needs to be performed on features located in a number of different planes, bottlenecks can ensue, even if the trimming process is automated.

Eck Plastic Arts (Binghamton, NY) ran into this very problem. The company solved it artfully by implementing a system of 5-axis trimming with a CNC router. This contract manufacturer offers its customers a wide range of services, including rapid prototyping, plastic fabrication, injection molding, vacuum forming and CNC machining. The diversity of its services has resulted in a diverse customer base as well.

CNC Programmer Paul Goodwin described the trimming problem: ?In 2006, our company was awarded a project that involved vacuum forming multi-faceted industrial equipment covers with a lot of slots, bosses, and clearance holes. Up to that point, we were trimming vacuum formed parts on a 3-axis mill. If the parts were complex, like these were, it could literally take days to do a small number of them.

?These were very nice 18 in to 20 in long rectangular covers,? continues Goodwin. ?Unfortunately, they had slots and clearance holes on the sides, and all sorts of funky edges that needed trimming. We were spending a lot more time setting them up on our 3-axis mill than we were doing the actual trimming. We would have to orient the part in one direction, run what we could, then tear that setup down, set it up again, reorient it, and run the next side, until all of the trimming was completed.?

The Eck Plastics manufacturing team decided that this work could be performed considerably faster and with much less manual labor on a five-axis router, so they purchased a VMS 5-axis router with a Fagor controller. The company had already been using Mastercam CAD/CAM software from CNC Software Inc. (Tolland, CT) to program its 3-axis mill and routers. Familiarity with this CAM software made it very easy for Goodwin to make the transition to 5-axis programming on the new router.

To make the work go even faster, he took advantage of the company?s software maintenance contract to download the latest version of the software, called X3 Router, even before hard copies of the program were officially released.

The combination of the 5-axis router and 5-axis programming dramatically shortened the trimming cycle. Working from a solid model of the part, Goodwin used his Mastercam library of tools and operations to automatically generate efficient trimming toolpaths. He relied heavily on the software?s computer simulation capabilities to verify that all the required material had been removed, while assuring that the equipment made appropriate but efficient clearance moves to avoid crashing the head or cutting tools.

Fast forward to today: This capability gives Goodwin the confidence that the machine operator can set the part up and just let it go, trimming all the features in multiple axes, typically without ever having to flip the part. As a result, operations that once took days and required as many as five set-ups can now be completed in an hour or so with a single set-up.

Many plastics molding and fabricating shops have machining capabilities that allow them to manufacture, or at least repair, fixtures and tooling. So machining is viewed as an ancillary process that is confined to the tool room. But Eck Plastic Arts takes a different view. Its manufacturing team considers machining to be a primary process that can be integrated with other more traditional plastic manufacturing processes to the great advantage of its customers.

This was certainly the case for 5-axis trimming. As the result of the fast turnarounds it provides, Eck Plastics got additional projects of a similar nature and subsequently some short-to-medium production orders from this one customer. What?s more, the new approach to trimming is so efficient that Goodwin is now busy programming all of the vacuum-formed parts for 5-axis trimming.

– – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – –

Eck Plastic Arts, 87 Prospect Avenue, Binghamton, NY 13901, 607-722-3227, Fax: 607-722-3081, www.eckplastics.com.

CNC Software, Inc., 671 Old Post Road, Tolland, CT 06084, 800-228-2877 or 860-875-5006, www.mastercam.com.