This is a simple device that clips onto a filament reel and holds the end of the filament in place. There are currently different files for 1Kg Makerbot PLA, ABS and Matterhacker ABS and PLA style reels. There will be more styles in the future. It provides a place to insert the filament when not in use. It saves filament because the device does not damage or require bending the filament to keep it from unspoolingIt's best to print this with the chamfered side of the slot down. Pay attention to its position on the build plate (be sure it sits flat) because the part's top and bottom faces are not parallel. Note: Filamentsaver.stl is for 1 Kg Makerbot PLA reels. Filamentsavermathack.stl is for 1 Kg Matterhackers ABS reels, filamentsaverABS.stl is for 1Kg Makerbot ABS style reels and FilamentsaverMHPLA is for 1Kg Matterhacker PLA reels. If you find the Filament saver is too flexible and comes loose or doesn't hold the filament well, increase your infill. If you find it is too rigid to get the filament through the slot, decrease it. I have found 30-40% works best when printing with ABS. ABS is probably the best material choice, since it's a little more flexible, for this application. More reel styles soon to come check back!