3D printers such as the RepRap and Makerbot turn spools of plastic filament into just about any object imaginable. There’s a problem though: this filament costs about $40 a kilogram, and raw plastic pellets cost about 1/10th of that. Obviously, there’s a lot of room for improvement. The folks at Inventables are throwing $40,000 at the problem in a contest to build a machine that takes plastic pellets and turns it into usable plastic filament.

The object is simple: build a device that takes ABS or PLA pellets and turns them into a 1.75mm filament. The machine has to cost less than $250, be able to add colorant to the plastic, and be usable in a 3D printer. The winner gets $40,000, a laser cutter, a 3D printer, and a CNC milling machine courtesy of Inventables. Sign up on the official contest website and don’t be shy about sending your progress into the Hackaday tip line

If you’d like to get started, here’s a great page that goes over the basics of plastic extrusion, and a few attempts (1, 2) from [Adrian Bowyer] and [Forrest Higgs] that show exactly how hard this is. There’s also the Filabot that had a successful Kickstarter, but there’s apparently been no (or very limited) progress in the four months since the Kickstarter. I’ve even given this idea a go, but am currently stuck at manufacturing a proper auger. To put this in perspective, this is the moonshot of the current crop of 3D printers; a simple device to lower the barrier of entry to 3D printing is desperately needed, and we’ve got to give props to the Inventables crew for putting this contest together.