3FPD-Replicator 2X - Extruder Upgrade - REV4

This is an extruder upgrade designed specifically for the Replicator 2X, but with improvements like it is now suitable for use with FLEXIBLE FILAMENTS!!!!

*** OK...01May14, We have used a highly modified Recreus Hot End kit (by chopping the Aluminum Heat sink fins, tapping the thermistor hole to fit a STD Makerbot one, and insulated it) and the REV4 Extruder works out-of -the-box, but not optimally. We will be releasing the REV 5 extruders, and a newly modified Fan Duct REV 2 with a modifie