Rapid Prototyping: From Art To Part

Scanning for Fraud

Art and technology have started to come together in an unlikely place–under the gaze of 3D digitizers.

The VanDuzen Archives of Dallas has built a growing business around the use of imaging hardware and digital shape sampling software as tools to authenticate and conserve works of art. And in one recent job, the company helped ferret out a forged copy of Picasso’s Tete de Fernande, a bronze bust.

Speaking at the SME’s Rapid 2008 conference, VanDuzen president and CEO Nancy Hairston recounted how a major New York auction house, which she wouldn’t name because of confidentiality agreements, had become suspicious of a Tete de Fernande bust that one of its client wanted to put up for auction. The bust had supposedly been cast, in the 1920’s, from Picasso’s original plaster molds.

Art experts seeking to authenticate a casting such as this usually take a series of linear measurements using calipers and then compare the measurements to authenticated versions of the same casting. Size deviations bigger than shrink values for the cast material are one indication that a piece is just not right.

In the case of the bust, initial linear measurements showed it to be 15 percent smaller than three authenticated castings–including ones at the Tate Gallery in London and the MOMA in New York. “Bronze shrinks approximately 10 percent from the plaster molds, so that wasn’t a possible shrink value,” Hairston says.

To be sure, though, the auction house turned to VanDuzen, which took a high tech approach to measuring the sculptures. The company first digitized the suspect bronze as well as three authenticated versions of the Tete de Fernande using a portable Konica Minolta VIVID 9i non-contact digitizer. Hairston recalls that it took about 150 scans and six hours to digitize each piece.

The scan data was then analyzed using using digital shape sampling and processing (DSSP) software from Geomagic. The software let VanDuzen perform deviation studies that would be difficult or impossible to do accurately with linear measurements. One study that compared the total volume of the suspect bust with those of authenticated pieces. And another, a registration study, showed how well the busts line up with one another.

And it turns out they didn’t line up at all. Hairston says the registration study revealed that the suspect bust was off kilter due to the addition of excess material on its base. “Forger added material to the base to throw off liner measurements,” she says. Once that excess material was digitally trimmed, the suspect bust turned out to be 20 percent smaller than the authenticated models. “That’s what sunk the piece,” she says.

Aside from using 3D imaging to uncover fraud, VanDuzen has also applied the technology to conservation applications. It archives encrypted 3D data about art objects for use by restorers or to monitor the condition of a piece over time. “Conservators think it’s fabulous,” she says.

Desktop Modelers For Sale

To the growing list of low-cost desktop modeling systems that you might actually be able to buy, add the V-Flash from 3D Systems. The company early this month began shipping this $9,900 machine, bundling it with Alibre Design Software. The V-Flash marks the company’s first use of its new Film Transfer Imaging technology, which you can read about in this earlier post. One promising use for this new technology platform involves the direct digital manufacturing of custom hearing aid shells. Dreve Otoplastik, an earmold manufacturer, this month announced that has developed materials specifically for the V-Flash HA 230 system, a model designed for the hearing aid industry.

The Art of 3D Printing

The most important debate taking place in the additive fabrication circles today involves the role that direct digital manufacturing technologies will play in the everyday life of consumers. When, if ever, will significant amounts of our material goods be “3D printed” rather than molded, machined, cast or stamped? Will there be a desktop manufacturing system in every home, turning out on-demand goods?

No one understands the barriers and possibilities of a digitally manufactured future better than those engineers who control the practical aspects of design and manufacturing. Yet artists and industrial designers can provide some insight into additive fabrication too.

Paola Antonelli, the senior curator at the Museum of Modern Art’s department of architecture and design, points out that designers have been keenly interested in additive fabrication for about five years now. “The good designers understand what these technologies can and cannot do,” she says.

And judging from a new exhibit at the MOMA, designers understand that additive fabrication machines can do things that engineers haven’t quite dreamed of yet.

The exhibit, Design and the Elastic Mind, explores the often reciprocal relationship between science and design. And Antonelli filled the exhibit with objects and concepts that highlight what she considers disruptive or potentially disruptive technologies. Though the exhibit divvies them up differently than Design News readers would, these technologies include nanotech, computer-aided design, advanced actuators, biomimicry, robotics, motion control and 3D printing.

Just as we often do here at Design News, Antonelli uses “3D printing” as a catch-all term for all the computer-driven, additive fabrication systems, not just the few machines that actually use ink-jet deposition methods. And she picked some interesting objects to show what these technologies can do.

One 3D printing standout was the “sketch furniture,” from Front Design. This Swedish design group has come up with a system for “materializing free-hand sketches,” by combining video motion capture techniques and additive fabrication. Users simply make  full-scale gestures in the air to sketch out the object–think of the gestures as pen strokes. The motion capture technology records these gestures, saving them as 3D part data, which can then drive a laser sintering machine. The exhibit showed furniture that Front has produced with the system (click here for photos and video). But engineers may well look at the system and see the whiteboard of their dreams.

Another interesting exhibit showed the capability of 3D printing to create textiles. Usually we think of additive technologies as producing rigid parts or sometimes assemblies of parts that can move in relation to one another. Freedom of Creation, a Netherlands design group, has used EOS laser sintering technology to create textiles. These textiles have their “threads” interwoven layer-by-layer during the sintering process. Computer design allows the textile to take on a wide variety of properties, something that may interest engineers responsible for flexible goods.

Design for the Elastic Mind featured many other examples of 3D printing, from production automotive parts to chairs that push the build envelop of these machines. Check them out at http://www.moma.org/exhibitions/2008/elasticmind.

And visit Design News on-line next week for coverage of the exhibit’s other technologies.