Toys Updated for this century with CAE toolsToys Updated for this century with CAE tools

Ina world off Route 66 and just beyond the speed limit, there'sWeirdsville, a fast-moving society where even the baby buggiesare built for speed. It's a place where cars rule and racing isa way of life."

This quote, taken from animator Mainframe Entertainment's website,describes a new cartoon world based on model kits sold by TestorCorp. in the 1960s. To update the kits to match the 'toon figures,designers ventured into a world where engineering technology rules.

To make it happen, Ken Stark, mechanical designer for the hobbymodel leader Testor (Rockford, IL), downloaded the animated versionsof the characters and reverse engineered them to make injectionmolds. Along the way, he used advanced CAE tools and the stereolithographyprocess. "This project proved that design technology hascome a long way since the 60s," says Stark.

Although Testor now specializes in car and airplane model kits,it sold thousands of Weird-Ohs model kits in the 1960s and 1970safter purchasing Hawk Corp., inventor of the car- and motorcycle-crazeddenizens of the fictitious town of Weirdsville. Four main characterscomprised the original toy line: Daddy-O Chassis taught auto shopin the high school; Mama B Chassis ran the local diner; Baby wastheir speed-crazed toddler; and the coolest guy in town was Davey,deeply in love with his motorcycle, Stella.

When the oil crunch hit late in the 1970s, hot rod fever waned,along with much of the interest in
the Weird-Ohs model kits. Testor went on to make car and airplanemodel kits, expand its popular hobby paint and finishing materialsline, and establish itself as a big player in the growing artsand crafts field.

Weird-Ohs Reborn

Still, Testor never quite forgot the Weird-Ohs. In the secondhalf of the 1990s, Gary Cadish, executive vp, sales and marketingfor Testor, shopped around the idea of a television cartoon basedon the Weird-Ohs. And in 1999 Mainframe Entertainment, a Canadiananimation company that specializes in computer-generated imaging,brought the hot rod characters back to animated life.

The originals were definitely 60s types, so Mainframe updatedtheir looks for today's young TV watchers. Popular in Canada,the Weird-Ohs made their U.S. television debut in November 1999,and Testor decided to update the model kits to reflect the newcartoon. And that's where Ken Stark entered the picture.

"We wanted to rerelease the original main characters-Davey,Mama with Baby, and Daddy-as they appeared in animated form,"recalls Stark. To incorporate the new look in the kits, only thefaces needed to be updated, so Stark's mission was to create newheads to go on the original torsos.

Before computerized design, making model kits required timeand highly trained specialists. A model maker would first carvea wooden model in 125 scale, from which a silicone rubber castingwas made. A rubber pattern mold followed, for creation of a ceramicduplicate. A specialist then traced the ceramic duplicate witha tracing milling machine to make a tool for injection molding.And a polisher/engraver hand-polished and engraved details.

Updated Redesign

To revise the Weird-Ohs heads in the quickest and least expensiveway possible, Stark suggested pulling down the animation, enteringit into his computer, and reverse engineering it to create newcavities in the tools for the heads. "From there, we couldeither find a specialist toolmaker or try new technologies,"he adds. "When I spoke with a toolmaker that we work with,Ferriot Inc., they told me it could be done."

First, he took the animation images from Mainframe, which werecreated in an animation program (SoftImage), and found a translatorthat could turn the images into IGES files. "This took abit of time, but I did find one that extracted all the necessarysurface data," he says.

Next, Stark opened the IGES files with FastSurf, and couldthen manipulate them in Cadkey. (Cadkey is a hybrid CAD modelerwith solid, surface, and wireframe capabilities. FastSurf, anadvanced surfacing program, is part of the Cadkey Design Suite.)All the heads in the model kits, except for Mama, had to be attachedto the torsos, so he also needed to duplicate the existing kittorsos. HighRes Inc., which specializes in reverse engineeringsoftware and digitizing solutions, gave Stark spline definitionsof the torsos from which he could create surface definitions.

"I basically chopped the old models off at the neck, putthe new head on top of the torso, and blended the computer representationtogether in the neck area," he explains. To position thecharacters correctly and get the desired facial expressions, Starkworked with the Mainframe animators, and melded the sets of modelstogether.

Molding vs. Animation

The next step took the most time. "Animation programsdon't create things that can be manufactured," he adds. "Tomake the models manufacturable, I had to make a parting line forthe molds." In addition, the figures had several undercutsthat had to be removed. FastSurf let Stark manipulate node pointsof surfaces and remove undercuts that came into the system aspart of the animation images. This process took one week.

He then finalized the part design and sent the CAD files toa rapid prototype subcontractor (3D Systems) to have two setsof SLA prototypes made. "We painted one set and used it todemonstrate the upcoming character faces at the annual Hobby TradeShow. The second set was sent to the tool shop, which cast alloycavities using the prototypes as the patterns," adds Stark.

While he admits it would have been quicker and less costlyto make a sintered rapid tool, there was not enough time to tryout the new process. "We needed to duplicate intricate detailsand didn't know if this process would work the first time out,but it is definitely a consideration for the next batch."

Molds for the heads and torsos alone are about 3 inches highby 112 inches wide. The fully assembled models are 6 to 8 inchestall. According to Stark, details reproduced by the alloy castingsare so fine that even fingerprints can be duplicated.

It took one month to do all the computer work and obtain therapid prototypes for all three characters. Toolmakers createdthe finished tools in roughly eight weeks. The Weird-Ohs got backon their motorcycles and hot rods for the 2000 Testor catalog.