Monday, November 17, 2014

3D printing and iSTREAM innovate car manufacturing

If you're a long-time reader, you know that I'm a car nut. I don't do much work on my car myself, but I love new cars and new technologies. The car industry is in the middle of two transitions: The first is the transition from exclusive gasoline power to a mix of energy sources--gasoline or diesel with electric, electric stored in batteries, electric dynamically generated with a fuel cell, and even gasoline or electric with pneumatics (Peugeot-Citroen's Hybrid Air.)

The second is the widespread application of intelligence to cars. By that, I mean the infotainment and telematics systems that integrate entertainment, navigation, online information, sensors, safety systems, controls, smartphone integration and even drive-by-wire systems. In the 1990's, automakers began adding these systems to their cars, starting with the German luxury brands. The problem was that the electronics were sourced from multiple vendors and were poorly integrated, which led to reliability problems for BMW, and particularly for Mercedes-Benz, which had long had a reputation for "bulletproof" cars. As carmakers greatly improved their cars' mechanical integrity, they simultaneously introduced a plethora of new points of failure with electronics. Today, these systems have improved but remain a sore spot--Consumer Reports' latest car reliability survey found particular problems with the following brands:

  • Fiat Chrysler's Jeep, Ram, and Fiat placed at the very bottom of the rankings, due in part to their electronics. (The Fiat 500L was the worst car in the entire survey, by a significant margin.)
  • Ford and Cadillac continue to struggle with their infotainment systems, MyTouch and CUE, respectively. GM does have some very good systems, but CUE is considered to be the worst infotainment system on the road by many car reviewers.
  • Nissan's Infiniti reliability ratings fell 14 places in one year, largely due to the Q50, which replaced the popular G37 for 2014. The big problem with the Q50 is that Infiniti switched to a numb "drive by wire" system for steering, which combined with problems with the car's In Touch infotainment to pull the car's ratings down.
Now, we're entering a third transition, this time in how cars are manufactured. The development that's gotten the most press is Local Motors' Strati, which has a 3D-printed body, chassis and seats, and a Renault power train. The Strati looks somewhat like an oversized toy car, and it currently takes 44 hours to build the 3D components, but it's more a harbinger of things to come than a viable product in its own right. Fairly early on in automobile manufacturing, bodies ("coaches",) chassis and engines were built by different companies. For example, Duesenberg, which at one time made the most expensive cars in the world, actually built only the engines and chassis. Local Motors' approach opens up that possibility again.

Start with a high-volume, standardized chassis, with or without an engine and transmission. Enable manufacturers to build interchangeable parts--different chassis, suspensions, engines, motors, transmissions and power sources, all that fit within the same 3D "envelope" and with the same mounting points for the body. Next, print the body, doors, hood and seats, install the glass, lights, instruments, airbags, infotainment system, telematics and other hardware, integrate the components and attach the body to the chassis. Depending on the chassis and powertrain, you could build anything from a two-seat roadster to a mini-CUV on the same chassis and assembly line. You could literally customize not just the colors, but the designs of the cars, by making changes to the cars' CAD files. And, by designing the chassis to include the safety crumple zone, you'd have even more flexibility in how to design the body.

Another approach is being pioneered in the U.K. by legendary car designer Gordon Murray. He claims that his manufacturing process, called  iSTREAM (for iStabilised Tube Reinforced Exo-Frame Automotive Manufacture,) can build cars with 85% less capital investment and 60% less energy than today's auto plants, in plants 20% the size of existing plants with comparable capacity, and with cars that generate 40% lower CO2 emissions over their working lives. iSTREAM eliminates stamping presses, which are extremely expensive, require very expensive tools, use enormous amounts of power and take months to switch from one design to another, Instead, the body panels are made out of honeycombed sandwiched composite materials, which are lighter than steel but stronger. The system uses lasers and CNC machines to cut, bend and weld metal tubes into an integrated chassis and roll cage with front and rear crush zones. That dramatically decreases the load that the body panels have to bear, while still enabling iSTREAM-based cars to exceed European safety standards. Gordon Murray claims that the iSTREAM manufacturing process creates cars that weigh half as much as comparable vehicles, and can scale up to full-size sedans, SUVs and minivans. 

To date iSTREAM has been used for producing prototypes of two electric-powered city cars, the T.25 and T.27, and has been used to build prototypes of a Yamaha electric city car, the Motiv.E. The iSTREAM weight advantage enables electric cars to use batteries with half the capacity, and therefore half the cost and weight, of batteries in conventionally-built cars. For example, Nissan's Leaf uses a 24kWh battery for an EPA range of 75 miles. A comparable iSTREAM car should get the same range with a 12kWh battery, or double the range from the same 24kWh battery.

Both the Local Motors and iSTREAM approaches lend themselves to smaller, more decentralized manufacturing plants, more customization options, and "just-in-time" manufacturing approaches that minimize both parts and finished car inventories. If they're successful, we could see the revival of "bespoke" cars, but instead of the highly-customized super-luxury models of today, they would be priced about the same or even less than comparable conventionally-built models.
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