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 modified cooling tube back to the extruders which has made a huge improvement in cooling the area around the filament in the extruder area before it feeds into the hot-end tube...***


-base is fully printable without supports(REV4=DESIGN TWEAKS include enclosed guide tube to control flexible filaments like FILAFLEX, and NINJAFLEX)
-arm is printable with only external supports for bearing slot(REV4=slight geometry tweaks)
-arm integrates feed tube mount as well
-tension spring geometry impro