A top mounted spool holder designed by me for use with the CraftBot 3D printer. You can fit one on each side of your CraftBot. This idea was inspired by Voidward's spool holder: http://www.thingiverse.com/thing:541173

You'll need three standard size pencils to assemble this thing. Print the main parts twice, with the parts mirrored in the second print if you want the symmetric look. To do that in CraftWare, go to "Objects" mode, select "Scale" and then "Mirror X". Also print and mount the anchor part, to keep the whole thing from falling into the printer if the filament should get stuck on the spool. There is also a filament guide part keeping the filament from tangling up outside the spool. Assemble the parts as shown in the pictures. Is that a cute puppy or what?