Tech Trends: Cost Control

30 Jun, 2005 By: Kenneth Wong

The Redback Spyder Strikes: A Nimble Approach to Auto Manufacturing

The Redback Spyder, a sports car from Down Under, is not as lethal as the venomous critter it's named after, but when it was first spotted at the 2002 Melbourne International Motor Show, it did cause some commotion and maybe even a few cases of temporary paralysis. The prototype continues to stir interest wherever it appears, be it at the SEMA show in Las Vegas, Nevada ( or at the grand reopening of Magnuson in Ventura, California. Its list of development partners reads like a who's who in automotive manufacturing: Recaro (, a seat manufacturer for Mercedes and Porsche; Lingenfelter (, an aftermarket engine package supplier for GM and Corvette; Hella (, a lighting systems distributor; Vintage Air (, an air-conditioning systems designer for street rods; and many more manufacturers of the same caliber. This is quite a playbill for a project that spun off from the vision of one man, Nick Tomkinson, who has no formal engineering training. Tomkinson and his business partner Mill Conroy attribute their success largely to IronCAD (

 Figure 1. Nick Tomkinson from Carbontech, a boutique carmaker, used his experience in welding and steel fabrication to mold the entire body of the Redback Spyder, shown here in its final stage.
Figure 1. Nick Tomkinson from Carbontech, a boutique carmaker, used his experience in welding and steel fabrication to mold the entire body of the Redback Spyder, shown here in its final stage.

Wrestling with the Big League

Tomkinson and Conroy are the two principal people behind the Victoria-based company Carbontech ( Already noted for its impressive Lamborghini Countach replicas, the company is part of a special breed of carmakers. Using an existing model as inspiration, they tinker with its outside architecture, its internal mechanism and its cosmetic components to arrive at something sturdier, speedier and flashier. They don't put together thousands of identical vehicles in an assembly line—they make their vehicles one at a time. They don't cater to the mass market—they sell to a pool of collectors and aficionados who are quite happy to postpone instant gratification for personalized service and an individualized product.

These cars, known as hot rods or street rods, bring charm, energy and personality to auto commerce. Hot-rod makers are car enthusiasts themselves, so the end product is a work of pride and a testament to quality craftsmanship. Most operate with a small crew of less than a dozen, but their creations rival, and sometimes even surpass, special-edition Ford or GM models in value and aesthetics.

A boutique carmaker such as Carbontech doesn't rely on an army of engineers and welders for its operations because it doesn't have such an army. The quality of the final product depends heavily on the part suppliers, accessory makers and manufacturing partners the project attracts. Tomkinson and Conroy foresaw that, in order to convince established industry leaders to work with them, they must come across as more than a pair of hobbyists creating something for their own amusement.

"To be a legitimate company, we needed to document every aspect of the car to be able to commission out various parts," Conroy says. This would show that they had invested time, talent and resources in the production process. The drawings would function not only as "a complete workshop manual," he says, but also as "a comprehensive selling tool." That's why they called Rob Patterson.

Finding the Right Tool

Rob Patterson, a former aircraft drafter, has churned out CAD drawings for more than 22 years. While he was teaching product designers how to run SolidWorks and IronCAD at the Royal Melbourne Institute of Technology, he received an invitation from the Spyder's creators to recommend a CAD program. "I could have proposed SolidWorks, Solid Edge, Inventor, Pro/ENGINEER or IronCAD," says Patterson, who is equally at home in all.

On the other hand, Tomkinson was familiar with AutoCAD Release 14 only, and his recent foray into 3D CAD was confined to some preliminary bodywork done in TurboCAD. The challenge for Patterson was to identify a lightweight, midrange program that was not only easy to use but also easy to teach. After considering the budget, the scope of the project and his client's 3D experience, Patterson suggested IronCAD ( Patterson's decision was based on his trust in IronCAD's features for conceptual design, in-context assembly design and handling unanticipated changes.

Reverse Engineering, from Physical to Digital

Drawing from his tenure in welding and steel fabrication, Tomkinson molded the Spyder's entire body by hand. The design, full of fluidity, suggests motion even when the car is immobile (figure 1). This was also "the most complicated part of the car to model," says Patterson. He had to figure out how to accurately measure and digitally reproduce Tomkinson's fanciful creation. Patterson briefly considered point-cloud data transfer, a process he had some experience with, but he dismissed it when he recalled how time consuming and expensive it could be. "Nick [Tomkinson] and I came up with an idea to buy a digital laser-beam measuring device and mount it to a track and rail system," he says.

"All we needed were the x,y,z points for every 100mm on the body of the car. IronCAD has the ability to read the curve data points as ASCII files to produce profiles for the surface or solid loft feature. Then, using the software, we chose the best profiles to suit the loft and, like magic, the body was modeled. The result was excellent, with just 80 hours of work. The rest of the car was just a matter of 3D modeling and arranging assemblies and subassemblies." The rest of the car, for the record, comprises more than 2,500 parts. With only minor instructions from Patterson, Tomkinson has since become a proficient IronCAD drafter in his own right.

These CAD files proved invaluable when Carbontech decided to put the Spyder through a series of design changes to bring it to the United States market. "It had to be made to withstand inclement weather. The cockpit area had to be widened, it had to have a roof constructed and had to go from being an open roadster to a bubble coupe," explains Conroy. Because of IronCAD's dual-kernel architecture, Carbontech was able to communicate these design changes to its vendors, whether they were using Parasolid- or ACIS-compatible applications.

Watch Out for the Small, Nimble Ones

The Carbontech team loaded a laptop with the Spyder's CAD files and headed out to the SEMA Show. From its space inside Magnuson's exhibit area, it pitched the car concept to executives from parts suppliers and accessory makers. "Through IronCAD," Conroy recalls, "I demonstrated how the car was going to be made, stage by stage, showing them the build sequence." By the end of the show, the team had not only secured a number of manufacturing partners, but also netted an array of components donated to the Spyder project—among them, a bi-xenon headlamp system from Hella that had not yet been made public.
Figure 2. With 45 companies and individuals contributing to the project, Carbontech used IronCAD to make sure all the parts and components manufactured by its transatlantic partners would fit into the chassis and interior of its Spyder.
Figure 2. With 45 companies and individuals contributing to the project, Carbontech used IronCAD to make sure all the parts and components manufactured by its transatlantic partners would fit into the chassis and interior of its Spyder.

There are 45 partners (35 from Australia, 10 from the United States) involved in the Spyder project. Of them, 32 from Australia and five from the U.S. donated their products, services and labor to help build the first unit. Without the ability to exchange CAD files back and forth via e-mail, Carbontech would have had a difficult time determining how parts manufactured by its transatlantic partners would fit into the Spyder's chassis and interior, which are anything but standard (figure 2).

To compete with enterprises many times larger in capital and resources, Tomkinson and Conroy rethink manufacturing. In essence, they operate in much the same way a tier-one supplier does, only on a much smaller scale. They cultivate partnerships. They position themselves at the center of the web, commissioning the parts available, producing what's not readily available through CNC operations, and fitting the components together to realize their dream car. For about $350,000, it can be your dream car, too.

Tomkinson and Conroy are enjoying their beloved Spyder's newfound fame. They are more than a little tickled to find themselves working on equal footing with household names in the automotive industry. But their prized partnership, Conroy emphasizes, is the one with IronCAD, which lends their humble enterprise instant credibility and lets them communicate with major suppliers in the same engineering language.

Catch the Spyder

The Spyder is now nesting in Los Angeles, California. With the final finishes done, it's ready to go on a U.S. tour. It's booked to appear in several races presented by the Vintage Automobile Racing Association ( and at the Hermann International Booth at the Consumer Electronics Show (, among others.

Kenneth Wong is a former editor of Cadence magazine. He explores innovative use of technology as a freelance writer. E-mail him at

About the Author: Kenneth Wong