cold fjord writes: Popular Mechanics reports, "... making custom racecar parts out of carbon fiber is daunting. The only real method available is CNC machining, an expensive and difficult process that requires laying pieces by hand. To improve the process, Mark looked to 3D printing. But nothing on the market could print the material, and no available materials could print pieces strong enough for his purposes. So Mark devised his own solution: the MarkForged Mark One, the world's first carbon fiber 3D printer. Mark debuted his Boston area-based startup MarkForged at SolidWorks World 2014 in San Diego with a working prototype. The Mark One can print in carbon fiber, fiberglass, nylon and PLA (a thermoplastic).
... The main advantage of the Mark One: It can print parts 20 times stiffer and five times stronger than ABS, according to the company. It even has a higher strength-to-weight ratio than CNC-machined aluminum. ... Mark says that he imagines this machine is for anybody who wants to print in a material as strong as aluminum. Beyond racecars, it could be useful to industries like prosthetics. "