So you've got a 3D printer. What do you do with all of your 1-, 2- and 3.0's that you had to print out before perfecting your desired gewgaw? Those rolls of ABS filament you used to make them are affordable, but not cheap.
Thanks to German programmer and inventor Marcus Thymark, you may soon be able to grind your old projects up and re-extrude them into fresh filament, ready for another go-round.
Thymark's invention is called the FilaMaker, which is topped with a hand-driven mini-grinder that crunches your plastic into bits, which are then melted and extruded by the rest of the machine. Unless more design progress is made, the grinding looks to be a bit of a messy process. (You needn't watch this whole video—it's painfully shaky and nearly ten minutes long—so just scan to get the idea.)
The bad news is the FilaMaker's not ready yet; Thymark's still working on the melter and extruder. But the good news is, he's opted to go open-source on it. You can stay abreast of developments here.