About this 3D model

Video here: http://youtu.be/bSbYbVXHCSANeat little two piece pulley and block so fit on top of an 8mm or 5/16" threaded rod, or screw it to the underside of a shelf above your printer. The two pulley halves just fit together without the need for glue.this is the best filament feed system I have come up with, it is very fast to change and lets you run multiple spools on a rack beside your printer http://www.thingiverse.com/thing:28944 or between them like I have done here.Mine clips into the top rails of my Mendel Prusa via the mounting clamp I have used on other similar projects.