3D Renderings in Color

Stereolithography is now a teenager, and like any teen has found a diverse number of ways to accomplish a given task. Prototypes are generated from photo-sensitive resins using laser light, build-ups from plastic that's heated to flow like inks, layers of paper, and computer-driven routers milling down blocks of plastic. For full effect, the finished article could be coated with a sealant and painted, adding time to the process but producing an evocative tool for demonstration of concept.

Z Corporation, Burlington, MA, has put on the market the Z402C 3D color printer, which is capable of rendering parts in 24-bit color from a range of sources, including many native CAD formats. The system has most of the components from the company's Z402 unit, adding special software and a kit that permits conversion between monochrome or full color mode. Switching between the two modes takes about 15 minutes.

The company's process originally was developed around a starch-and-sugar based powder that builds parts layer by layer as a binder is sprayed in the pattern of the component at that level. A second powder, based on plaster, was later added, and is recommended for the color printer as it produces colors that are more brilliant.

The print color head in the conversion kit functions like that in an inkjet printer -- magenta, cyan, and yellow colors are drawn from separate tanks, and added to the powder only as a 0.25-in.-thick shell covering the outside of the part (think of an M&M). The system software works with 3D color data formats, including VRML, and an STL paint program is available that allows users to import and colorize an ordinary STL file. The Z402C printer, sized akin to an office copy machine, has a build volume of 6 cubic in., and a build speed of 0.33 to 0.66 vertical in. per hour at 0.007-in. layers.

The conversion kit is also offered as a retrofit package for owners of Z402 printers, and is being sold by consumer computer stores.

--RM

For more information: Circle 555 - Z Corporation, or connect directly to their website via the Online Reader Service Program at http://www.1rs.com/012df-555