About this 3D model
This is the front extruder carriage for Jon Lawrence's 300mm No sag Y extension for the printrbot Simple 2013-2014 http://www.thingiverse.com/thing:242185 This version has a clamp that attaches to the upper 8mm pole and then using a m3 nut and bolt, it will clamp onto the 8mm rod, locking it in place. updated 11/22/2014 Upper_Pole_clamp2.stl is an updated version with a wider gap to the upper pole clamp. Allows Tighter clamp and can be tightened down the line. I suggest a washer up top and bottom to prevent the screw from wearing on the plastic.