"As vivid as a 3D CAD model is, it just doesn't tell you as much as a physical model can about what will come off the production line. We're making more money by creating prototypes for our sales force, giving them something concrete and convincing to show major auto companies and private-label customers." – Matt Lamb, Tire Designer, Continental Tire

If you drive, ride, or bike, chances are good you are rolling on “Conti” tires. Continental Tire the Americas, LLC is a group of the Germany-based Continental Corp., which is the number-one tire maker in its home country, number two in Europe, and number four worldwide. The products are sold under a host of different brands, including Continental, General Tire and Uniroyal in Europe.

At first glance, tires are just tires, but a surprising amount of thought goes into every line of Continentals. What kind of vehicle is it going under? What is the focus? Stopping power? Fuel economy? Performance? And of course, what should the tread look like?

Tread design is where the rubber meets the road in tire making. It is equal parts engineering and aesthetics, and designers need prototypes on demand to drive good group decisions. Early in development, tire designers take input from marketers and engineers who separately lay out requirements for each new line of tires. Designers synthesize the input and come up with dozens of potential tread designs. Every zig, zag, groove and gap has a specific purpose and had better have eye appeal. “Looks aren’t everything, but everyone wants a cool-looking tire,” says Matt Lamb, a Continental tire designer based in Ft. Mill, S.C.

Défi

Quickly Generating Numerous Tread Samples

From dozens of initial concept drawings, designers develop half a dozen into full-fledged three-dimensional computer-aided design (CAD) models. Although tires may seem like simple things, they’re very complex to design. They’re a torus shape – that is, they have a curved circumference and curves in the cross section. To simplify and accelerate design work, Continental developed proprietary modeling software called TireWizard that operates on top of its 3D CAD software.

Years ago, Continental recognized the value of turning the CAD models on their computer screens into rapid physical prototypes that employees could hold in their hands while evaluating design alternatives. “As vivid as a 3D CAD model is, it just doesn’t tell you as much as a physical model can about what will come off the production line,” says Lamb.

Solution

3D Printing

Continental invested at that time in a Fused Deposition Modeling (FDM) 3D printer. As advertised, it created 3D prototypes. Whether they were rapid prototypes was open to interpretation. Every printing job took 50 hours or more.

Frustrated with the slow printing action, Continental decommissioned the machine and evaluated alternatives for upgrading. Speed, of course, was the main consideration. Continental tire designers needed a fast machine that could churn out prototypes without a lot of wasted time and effort. After months of evaluation, Continental representatives determined that the ProJet®CJP full-color 3D printer was the fastest 3D printer on the market, as well as the most affordable to purchase, operate and maintain.

Résultats

Speed And Efficiency Up, Cost Down

Continental est ravi de son investissement. L'imprimante ProJet imprime des échantillons de sculptures de pneus de 10 x 5 pouces (254 x 127 mm) en cinq heures, au lieu de 50 heures avec la technologie FDM. Les économies de temps deviennent exponentielles lorsque Continental choisit d'imprimer trois échantillons différents à la fois, ce qui était impossible à réaliser avec la machine FDM.

Outre la rapidité de l'imprimante ProJet, son coût d'exploitation est également deux fois moins élevé que celui de l'imprimante que la société a mise hors service. Un échantillon de sculpture coûte 100 $ en matériaux, contre 200 $ pour un échantillon produit avec l'imprimante FDM.

Another dramatic difference between the two devices is the Projet CJP's surprisingly low maintenance requirements. To create a prototype, the FDM device squirted a glue-like substance from a small nozzle that would regularly clog. Even worse, it would then harden. Lamb and his colleagues had to regularly dismantle, clean, reassemble and recalibrate the machine – a task that was clearly beyond the scope of routine maintenance.

The ProJet’s speed and negligible maintenance requirements have created time for Lamb’s division to accomplish more work in the same amount of time, including printing models for a commercial tire group in Illinois that remotely downloads 3D files to the 3D printer in Ft. Mill.

« Nous sommes extrêmement satisfaits de l'imprimante ProJet, car elle est rapide » déclare Lamb. « Nous passons davantage de temps sur la conception et moins de temps pour réalisation des prototypes et la réparation de machines qui n'était pas censées tomber en panne. Nous disposons à présent d'une plus grande flexibilité dans le cycle de conception pour développer, discuter, argumenter et affiner les conceptions de sculptures destinées à mieux satisfaire nos clients.

Outre nos économies en achat et en matériau, nous réalisons un chiffre d'affaires plus important en créant des prototypes pour notre force de vente, qui fournissent des éléments concrets et convaincants à montrer aux principales sociétés automobiles et aux clients des marques privées. Ce processus représentait trop de travail auparavant, mais il représente un avantage important pour nous dans la mesure où nos concurrents n'ont que des esquisses à présenter. Grâce à l'imprimante ProJet, tout roule à merveille chez Conti. »