Picture an assembly line not that isn’t made up of robotic arms spewing sparks to weld heavy steel, but a warehouse of plastic-spraying printers producing light, cheap and highly efficient automobiles.If Jim Kor’s dream is realized, that’s exactly how the next generation of urban runabouts will be produced. His creation is called the Urbee 2 and it could revolutionize parts manufacturing while creating a cottage industry of small-batch automakers intent on challenging the status quo.Urbee’s approach to maximum miles per gallon starts with lightweight construction – something that 3-D printing is particularly well suited for. The designers were able to focus more on the optimal automobile physics, rather than working to install a hyper efficient motor in a heavy steel-body automobile. As the Urbee shows, making a car with this technology has a slew of beneficial side effects.Jim Kor is the engineering brains behind the Urbee. He’s designed tractors, buses, even commercial swimming pools. Between teaching classes, he heads Kor Ecologic, the firm responsible for the 3-D printed creation.“We thought long and hard about doing a second one,” he says of the Urbee. “It’s been the right move.”Kor and his team built the three-wheel, two-passenger vehicle at RedEye, an on-demand 3-D printing facility. The printers he uses create ABS plastic via Fused Deposition Modeling FDM. The printer sprays molten polymer to build the chassis layer by microscopic layer until it arrives at the complete object. The machines are so automated that the building process they perform is known as “lights out” construction, meaning Kor uploads the design for a bumper, walk away, shut off the lights and leaves. A few hundred hours later, he’s got a bumper. The whole car – which is about 10 feet long – takes about 2,500 hours.Photo: Sara PayneBesides easy reproduction, making the car body via FDM affords Kor the precise control that would be impossible with sheet metal. When he builds the aforementioned bumper, the printer can add thickness and rigidity to specific sections. When applied to the right spots, this makes for a fender that’s as resilient as the one on your Prius, but much lighter. That translates to less weight to push, and a lighter car means more miles per gallon. And the current model has a curb weight of just 1,200 pounds.To further remedy the issues caused by modern car-construction techniques, Kor used the design freedom of 3-D printing to combine a typical car’s multitude of parts into simple unibody shapes. For example, when he prints the car’s dashboard, he’ll make it with the ducts already attached without the need for joints and connecting parts. What would be dozens of pieces of plastic and metal end up being one piece of 3-D printed plastic.