An item printed with the Spectrom device.

Full color printing is generally a privilege limited to professional and high-end consumer 3D printers, so the more casual user is likely stuck printing in one or two colors. But Cédric Kovacs-Johnson and Charles Haider, both chemical engineering undergraduates at the University of Wisconsin-Madison, say they have come up with a solution: a sub-$100 device that upgrades desktop 3D printers to print in a full rainbow of colors. They call it Spectrom.

The system is compatible with fused deposition modeling 3D printers that use a standard-size spool of filament. FDM printers melt string-like plastic bit by bit and lay it down in layers to create an object. Spectrom adds dye to the plastic as it melts, allowing printers to shift between colors.

“What we find really innovative in our approach is we went back to the roots of paper printing and we said, ‘How did they accomplish a range of colors?’” Kovacs-Johnson said. “We can print everything from dark blue to pink to red and everything in between.”

Desktop 3D printer makers have generally gotten around the one color problem by adding more than one print head. botObjects, a desktop printer maker that has been teasing the community for years with its full-color printing abilities, has revealed that its machine works by combining different pre-colored filaments.

Spectrom doesn’t require a specialized printer to work. The idea is that you install it on your existing printer and you’re ready to go. Your computer outputs code that tells the device when to switch between colors, and your printer operates as if it was printing with a regular filament spool.

The duo didn’t arrive at the method immediately. During a year and a half of development, they tried combining different colors of filament and different dyeing methods. They experimented with both ABS and PLA plastic.

“It was just a whole ton of trials before we looked at something and said, ‘Oh! That works exactly how we thought,’” Kovacs-Johnson said.

Their invention won them two first place prizes at UW-Madison’s Innovation Days competition last month. Haider and Kovacs-Johnson now have a patent pending for Spectrom and are looking at bringing more people onto the team. They are considering working with larger companies or launching a Kickstarter campaign.

Haider said that at the end of the day, they are hobbyists too, and as a result are focused on making sure it is compatible with any printer.

“We want to get it out to as many people as possible,” Haider said.

Via Gigaom