Replicator 2X Extruder Drive Block Upgrade

# Makerbot Replicator 2X Extruder Drive Block Upgrade

## UPDATE Jan 30, 2014
New V2 files uploaded. A few minor changes were made that should create stronger parts that require less post-finishing. Also, a remix has been created based on user comments to create a version that uses an M4 flat head screw to mount the bearing. If you would prefer to use a screw, you can find that version here:
http://www.thingiverse.com/thing:237554

## Intro:
This is hopefully the last extruder drive block upgrade you'll ever need for your Makerbot Replicator 2X.

It is loosely based on the function of the official Replicator 2 (not 2X) upgrade:
http://www.thingiverse.com/thing:53125
and on the aesthetics of the whpthomas upgrade:
http://www.thingiverse.com/thing:79807

## Advantages over other drive block upgrades:

1. Includes a fully surrounded lower filament guide hole between the drive gear and the entry to the hot end. This is *ABSOLUTELY ESSENTIAL* when printing with