Sponsored By

September 21, 1998

5 Min Read
Stretching the limits of simulation for molds and prototype parts

At Arizona Precision Mold Inc., simulation technology is not a game. It is a way of building molds and prototype parts faster, better, and more cost effectively than using conventional methods.

Dennis Nealon, owner of APM, says what he does isn't magic, and there's no black art involved. He likes to call it his own brand of virtual reality. His secret, he says, is not being afraid to step outside the box and fully utilize the technology available (he has six seats of Pro/Engineer software from Parametric Technology Corp.).

For example, when a customer's engineers needed a prototype part for a new style of portable telephone charger, they looked into SLA (stereolithography). They were quoted 3-4 days and a "fairly substantial cost" from a prototype house, then came to APM to see if there was an alternative solution.


This is the Pro/E screen image of the A half of the mold.

Nealon, along with APM's head of design engineering, Michael Hadley, told the customer "no problem." Overnight, using Pro/E and a 3-D solid model mock-up sent as a CAD file via electronic data transfer by the customer, Nealon produced three sample parts machined from blocks of Delrin.

They began shortly after noon. Hadley first told the computer the size of each Delrin block and watched the cutter path in a wire frame format. He watched the cutter path run on simulation software next, proved it out using verification software, and then sent the program to the CNC machine.

The Delrin blocks were placed in the CNC machining center at 3:30 p.m. to run lights out that night. The result was prototype parts, ready the next morning, that came within .001 inch of the customer's initial models. These prototype parts, needed by APM's customer to gain approval on size and shape, reflect just one way APM uses its expertise with Pro/E solid models to create parts. While other moldmakers may talk paperless mold design and build, APM is doing it.

A Paperless Plant
There really is an absence of paper in the mold engineering, design, and moldmaking areas of the plant. There are no prints lying anywhere in the newly constructed, 9000-sq-ft mold shop, which now has a molding department with two new Mitsubishi presses and one new Cincinnati press.

Nealon says the only prints the moldmakers use are one or two "reference" sheets. There aren't hundreds of numbers to crunch, just a few critical dimensions. The CAD/ CAM system does everything else.

Using this technology allows APM to make molds in half the time it generally takes with conventional methods. Although many shops have Pro/E or other types of CAD/CAM software, few have learned to push the envelope so effectively.

Recently, APM completed a mold to produce fixturing components for Marui International Products Corp.'s El Paso, TX division. Marui is one of the three largest automotive suppliers in the world, specializing in car audio sound systems. The company has an injection molding facility dedicated to two-shot molding of buttons. The fixturing components hold these buttons in place during secondary operations.

"The thing I enjoyed about doing business with Arizona Precision is they are very progressive in their thinking and had good ideas about cost savings and design issues," says Dan Fischer, purchasing supervisor for Marui.

Although the ABS parts didn't have to be pretty, they had to be functional. Fischer says Marui realized a considerable savings both in cost and time by working with APM.

"Their delivery was phenomenal compared to other quotes we received," adds Fischer. "We were very impressed with not only how they use technology but how they support their customers' needs." The mold was completed in four weeks, which Fischer says went straight to Marui's production floor, and the customer had 150 small, complex, ribbed, and detailed parts in hand three days later. An important key to the short lead time for this mold, in addition to using virtual manufacturing techniques, was the fact that APM burned the details using one complex copper-impregnated electrode per cavity, rather than the conventional multiple electrodes.

Nealon has long been a proponent of maximizing technology available, something he believes too many moldmakers don't do because they've become entrenched in old methods.

Along with all this technology come pitfalls. "Technology has happened so fast, there's nothing binding it all together," he says. "This creates brand new problems that we're just now learning to overcome."

One of the biggest technological hurdles mold designers must deal with is systems incompatibility. Nealon says difficulties arise when different systems are used to design a part, design a mold, and manufacture the mold. Although the technology of various software systems is similar, they cannot speak directly. Transferring the data to an Iges file, the language of the lowest common denominator for all types of software systems, often results in information being misinterpreted or lost.

The benefit of using Pro/E is that each module operates from the previous module, i.e., Pro/Manufacturing runs from Pro/Mold which operates from Pro/Design. This type of integration prevents lost data or errors in translation.

An Invitation
APM is open to any moldmaker who would like to come and see a firsthand demonstration of the use of 3-D models to cut cores and cavities. Nealon and Hadley aren't shy about sharing what they've learned. In fact, Nealon believes people in the industry need to work together more to share ideas and solutions to problems they encounter. "We need a better spirit of cooperation to do what's best for the customer," he adds.

Contact information
Arizona Precision Mold Inc.
Mesa, AZ
Dennis Nealon
Phone: (602) 539-1999
Fax: (602) 539-1998

Sign up for the PlasticsToday NewsFeed newsletter.

You May Also Like