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　　PORTLAND, Ore. — Three-dimensional printing has matured almost overnight from a novelty market for making knicknacks into a fledgling industry workhorse for making prototypes that could eventually displace the venerable manufacturing capabilities of injection molding or computer numerical control (CNC) subtractive machining, and the global tool-and-die supply chain supporting them.

　　Today companies like Stratasys Ltd. and 3D Systems Inc. are providing the necessary industrial-grade 3D printers, but they have yet to prove the mettle of additive manufacturing to the mainstream industry. That is one reason they recently lent their expertise to theSpring 2014 Additive Manufacturing Grand Challenge, hosted by the Virginia Polytechnic Institute and State University (a.k.a. Virginia Tech) and funded by the Air Force Office of Scientific Research, the National Defense University, Robotic Research LLC, and the Stiefel Family Foundation.

The Spring 2014 Additive Manufacturing Grand Challenge is hosted by Virginia Tech to demonstrate the utility of 3D printed vehicles.

　　Christopher Williams, a professor at Virginia Tech, told EE Times in an interview:

The whole point of 3D printing is to reduce the complexity of the supply chain -- thus instead of manufacturing all these pre-made parts and shipping them around the world to be assembled, you just send a 3D printer, an electronics kit, and a bucket of raw material to the place the device is needed. That's the vision. 

　　The idea of the Grand Challenge is to prove that if you send 3D printers into the field, you can print a vehicle in a few hours that is perfect for a specific mission. Today we tend to build very expensive vehicles that have to be a jack-of-all-trades, but with 3D printing you can build an inexpensive vehicle that exactly fits the needs you have at a specific site, and then put it on the shelf until its needed again -- or just throw it away.

　　

　　The first Additive Manufacturing Grand Challenge is open only to Virginia Tech students, but, if successfull, the hope is to duplicate it with competitions in which every major university will be able to participate.

　　"This is the first competition of its kind," Williams told EE Times. "But it's a pilot competition that we are hoping to open up to contestants from other universities starting as early as this fall."

　　The sponsors' motivations were twofold: first, to demonstrate that 3D additive printing is capable of more than just novelties and toys, but can produce usable industrial-grade devices that could eventually displace the whole subtractive manufacturing supply chain. Second, the sponsors want to begin creating a pool of talented engineers trained in how to make maximal use of 3D printing technology.

　　Williams told us:

We haven't finished our assessment of how much the students are learning, but the data we already have is overwhelmingly positive. The students are reporting a substantial amount of learning about mechatronics in particular and 3D printing in general. Almost all of them had minimal knowledge in these categories before the contest, and looked at the competition as a motivator, as a reason to go learn something they always wanted to learn, but never had time for. They decided, "Why not now?"

　　Initially, 200 students signed up on 72 teams, all of which built first-generation prototypes that were put through a month-and-a-half of informal competitions. From that field, 36 teams were invited to create complete designs for evaluation, which were subsequently narrowed down to 14 -- seven ground vehicles and seven aerial vehicles.

　　"All of the 14 vehicles are fully operational -- they all fly or drive -- but they all also have their own strengths and benefits," said Williams. "And its possible that one of these vehicles might finish last in our competition, but on a different course might do very well. That's the beauty of 3D printing."

　　The competition attempts to answer two questions, one military and one civilian. Can the military can deploy 3D printers at forward bases and print out reconnaissance vehicles on demand? And can civilian first-responders print out search-and-rescue vehicles with just the right capabilities to start searching for survivors while waiting for the rescue teams to arrive?

　　The finals competition is being held May 15, 2014, in a gymnasium at Virginia Tech where two courses, one for ground vehicles and one for aerial vehicles, have been set up. Each course has four waypoints, which the vehicles either drive or fly to while avoiding obstacles, and then take a picture of the waypoint.

　　According to Williams:

For the ground vehicle course, between each waypoint is an obstacle like a steep incline or a rubble field or a tunnel, where you must thread the needle, or, in one case, a maze that demonstrates sharp turning capability. The aerial vehicle's course [features] different obstacles, such as going under a bar like doing the limbo, or hovering down inside an open-top tower and taking a picture of the waypoint. And there's one waypoint that is inside a window that they have to fly close to and take the picture through the window.

　　To quantitatively judge the quality of the picture, the waypoint itself is an optometrist's eye chart, so the judges just score the lowest line they can read to determine how many points a team receives at that waypoint. Only one team made it to the finals with two vehicles -- one ground and one aerial. And all the vehicles carry a GoPro camera as a payload, but vehicles can score extra points for carrying an additional payload.

　　The second part of the judging is the teams' use of 3D printing.

What makes this competition special is that you get to selectively place material, which is completely different from the old rules, like injection molding and machining, which constrain your creativity. But 3D manufacturing literally lets the designer control every drop of material, so we can print more complex and lighter-weight objects.

　　In the prize category called "effective use of additive manufacturing" the judging incorporates into the score the time it takes to print the parts for the vehicle, the time it takes to assemble the vehicle, the amount of material used, and the number of non-3D-printed components.

　　Each team got an electronic components kit from Robotics Research. In addition, all the aerial teams had to use the same rotor blades, but the ground teams got their choice of using provided wheels or treads or of printing their own.

　　Teams each had a choice of all three types of 3D printers available today: a fused deposition modeling (FDM) printer from Stratasys; a poly-jet printer (the only one that supports a range of materials with properties from rubber to rigid and transparent to opaque) also from Stratasys; and a selective laser sintering (SLS) model, which uses a laser to harden and bond small grains of plastic, ceramic, glass, or metal, from 3D Systems.

They could use any of the three printers, but the catch was that the entire vehicle had to be made on that single printer. We wanted to give them space to design, but they had to look at the tradeoffs -- the pros and cons -- between these three different technologies, which offer completely different ways of doing 3D printing. Four chose FDM, seven chose poly-jet, and three chose SLS.

　　A total purse of $15,000 in cash prizes was made available by the Stiefel Family Foundation -- $3,000 for first prize in each category, ground and aerial, best performance and best design, plus $250 for each team that fields a functional vehicle.