Bridging the Divide Between Art and Engineering

The terms “artistry” and “moldmaking” have some odd connections. Certainly a finished mold often looks like a work of art – and not just to engineers. There also is the artistry involved in the mold’s design when dozens of components must function with the synchronized precision of a ballet. And there is that cliche – art to part.

But this syntax is not to the point. For years moldmakers have been looking at it in another way entirely. They want CAD/CAM software to help them meet the rising artistic demands of product designers. Frustration has been high because moldmaking is a quintessential engineering task. Software developed for it has so many engineering features that any artistic capability just seems to get in the way.

It’s no help, either, that the initial approach to designing a mold is diametrically opposed to the usual approach of an artist or sculptor. A moldmaker must turn the product inside out, then deconstruct it one surface at a time in order to generate the necessary steps. Artists and sculptors work the other way around – creating lines, colors, perspectives and shadings that reproduce an image from the mind or the physical world.

The conceptual differences between the two approaches dictate fundamental differences in the software packages. For years, the possibilities intrigued Dale Hillesland, owner of Paraflex, Inc. (Tacoma, WA) – a small mold shop, employing three people full time and one part-time. In business for seven years, its bread-and-butter markets are molds for consumer goods ranging from airline food trays and photo slide mounts to toys and industrial printer housings.

Hillesland regularly searched engineering trade shows, art expos and craft fairs. But nothing seemed to bridge the divide between art and engineering. That is, until he discovered ArtCAM Pro software for engraving. ArtCAM, from Delcam International Inc., was created specifically to turn tabletop milling machines into engraving tools. The software has been an instant hit with jewelry manufacturers and firms that produce awards. It also is widely used by engravers, sign makers, wood carvers, packaging designers, sports equipment manufacturers and many others with a need for artistic output.

Based in Windsor, Ontario, Delcam International is the North American operations of Delcam plc (Birmingham, England). Delcam is the developer of ArtCAM as well as software for tooling and complex surfaces – PowerSHAPE and PowerMILL – plus PowerINSPECT for coordinate measuring machines (CMMs) and CopyCAD for reverse engineering.

“As soon as I saw ArtCAM back in May 1998, I instantly wanted to have it,” says Hillesland, whose background includes a stint making molds on pantagraph-type milling machines. “I had never seen anything like it. It was the first time I had seen that kind of hand engraved detail produced by CAD/CAM software. The artistic slant was something that had been sorely lacking from everyday moldmaking.

“I watched ArtCAM develop as a product for about a year while I waited for the right project to come alone to justify the purchase,” he says. ArtCAM was, after all, $7,500 – a significant investment for a company with just three full-time workers, including Hillesland.

A Royal Opportunity

The ArtCAM business opportunity was a chance to bid on lucrative tooling work with a high degree of artistry in product design and packaging. The opportunity came in mid-1999 in the form of a bid package for a set of three plastic injection molds. The tooling produces a plastic castle for sale in pet stores to cat lovers.

mold case study 1

This indoor play space for cats was the brainchild of Michael Stamnes, president and owner of Irving Industries, Inc. (Anchorage, AK). Given the long Alaskan winters (wet or cold or both), pet owners there put a high premium on anything that preoccupies housebound pets.

As pet store owners know, human preferences rather than the pets’ determine what gets to the cash register. “Cute” and “ap pealing” are major factors in these decisions. Part of that appeal, Hillesland notes, is the Kitty Castle’s life-like detail and high quality surface finishes.

Up against two rivals for the work, Hillesland turned to Steve Kidd, owner of Cimtech Inc. (Gig Harbor, WA), an ArtCAM distributor in the Pacific Northwest. Cimtech helped Paraflex win the bid by using ArtCAM to cut Irving’s sample parts in aluminum.

“That sample proved to the customer that Paraflex could make a much more realistic and appealing castle than the competitor,” states Hillesland. The competitors managed little more than a basic-looking castle – attempts that people from Irving later told Hillesland were “cheesy.” Without ArtCAM, they were forced to use traditional etching methods to create a moldable brick texture.

However, winning the bid and doing the work were two different things. When Irving awarded Paraflex the work, Hillesland had yet to buy and learn how to use ArtCAM, so the system’s short learning curve became the critical path to his success. “I learned to use ArtCAM in three days,” says Hillesland. “The only ‘outside help’ that I had was a short on-site training course from Cimtech.”

This was enough to let Hillesland start work almost immediately. Product data in the AutoCAD Drawing Exchange Format (DXF) was read into ArtCAM as into any CAD system. “The DXF files had to be modified and that was a big learning curve,” Hillesland says. “But with that behind us, we are very pleased that Delcam chose DXF as one of its standard CAD input formats. Ninety percent of the files we get are from AutoCAD users. These guys are product designers, not toolmakers,” he adds.

Paraflex’s designer, Richard Ellis – a mechanical engineer with a bachelor’s and a master’s degree – built the model of the castle with ArtCAM. Ellis used ArtCAM’s color modeling plus some vector-based shapes for the basic underlying castle geometry. The ArtCAM color modeling process gave a good indication of what the finished tools would look like. Vector shapes were used to make the turrets of the castle.

mold case study 2

Irving Industries’ Kitty Castle measures about 18 inches at the base and is 22 inches high.

The brick and granite effects were added to the walls using ArtCAM’s texturing tool. “From this point on, Rich just needed a few edits and some smoothing to finish the modeling,” Hillesland explains. Toolpaths were then created to rough and finish the molds for prototyping parts.

There was the usual number of design changes. “The ease of use of ArtCAM made it simple and quick to modify the engineering as Rich went along,” Hillesland continues. “This helped us find a solution which worked technically and fulfilled the aesthetic requirements of the customer.”

Machining was done on P20 steel, commonly used for injection mold tooling. The steel was prehardened to 34 Rockwell C, making the metal hard to machine. Finish machining was done with a relatively large 3/16″ cutter (0.1875″ diameter). “We couldn’t use anything smaller because of the tight deadline,” Hillesland says. “We really had to push the metal. Anything smaller in cutters would not have held up.” Rough machining was done with 3/4″ ball-nosed cutters.

The jobs were cut on a three-axis Giddings & Lewis Inc. Fadal 40 x 20 vertical milling machine with a 22-hp spindle drive motor and a 10,000-rpm spindle. The process was speeded up by the extensive use of tooling inserts for detail. “The inserts allow the molder to quickly make tooling changes,” Hillesland says, “and they make the tool easier to build.”

Most metal cutting at Paraflex uses NURBS – an acronym for non-uniform rational B splines. NURBS programs generate true curves in the machine tool’s control, eliminating minuscule straight-line segments. “NURBS gives us a faster and more accurate way to machine directly from the solid model,” explains Hillesland. He began machining with NURBS in 1996.

“The CAM files got very big – an average of 33 MB per mold tool,” Hillesland says. “We split these into two 18 MB files and cut in two different directions. The parts had thousands of surfaces to be cut and the machine often went so fast it looked like a sewing machine,” he notes. The Fadal 88 CNC controller reads 1,000 lines ahead; Hillesland notes that some CNCs can only read three lines ahead.

“Everyone involved was blown away by the detail and quality of the finish in the first mold made in tool steel,” Hillesland says. “The only other way to achieve such a look would have been hand engraving. That would have been impossible within the budget and deadlines. Our competitors would not have tried, even if they had ArtCAM and knew how to use it.

The Right Tool for the Right Job

“What is really important for a business this size is being able to pay for a lot of software on the first job and still make a profit,” Hillesland says. “Also important is being able to deliver on time – taking into account the learning curve and the many changes that Rich had to make.”

Because ArtCAM is so much more an artistic tool than an engineering tool, Hillesland ran into some fit and function difficulties. Some internal corner radiuses were originally cut too tight and had to be recut. “ArtCAM wasn’t really designed to be used that way,” he explains, “but you can do this with it if you plan the job correctly.

“In doing mold work with ArtCAM, you have to remember that this is an art-type product and not an engineering-type tool,” Hillesland reiterates. “You need to design the part and tool around that fact. What Rich has done is taken ArtCAM up a notch in capability, up to a different level of true moldmaking. This is a lot more than just adding decorative inserts, although we do a lot of that, too.”
Hillesland is confident that he’ll recover his ArtCAM investment in the first year. He is sensitive to this because the last time he bought software – in 1997 – he paid $30,000 for a high-end Unix-based system. “We still haven’t gotten our money back from that,” he notes. “The software can find parting lines and that’s a big help. But a less costly PC-based system would have been just fine for nine out of 10 jobs that we do.”

Though the Unix package was used for some of the Kitty Castle, fine details, textured surfacing and adjustments to make the molds fit properly were done with ArtCAM. “ArtCAM still gives us better finishes than the Unix package,” Hillesland notes. “This has given Paraflex a level of quality and surface finish that other shops just couldn’t match.”

New Opportunities

ArtCAM has opened a whole new world of tooling in the packaging industry for Paraflex – aluminum tooling for vacuum-formed blister packaging. “This is very popular for premium-priced food and candy,” Hillesland says. “They need exotic packaging to help them stand out in the store. We are the first guys on the block to do this and we look forward to exploiting ArtCAM’s technology to go after work we previously were unable to bid.”

Another solid market for Paraflex is construction company logos used on the covers of underground vaults. These are scanned into ArtCAM from photos or business cards and they end up in foam molds. “They buy these foam tools a thousand at a time,” Hillesland says.

“The business is changing,” he summarizes. “We are getting more artistic work all of the time. Pretty soon, thanks to ArtCAM, we will go looking for this kind of work rather than just waiting for it to come to us. Right now, out here, no one’s doing it.”