Pitbull XL Extruder

This is a remix of the excellent Compact Bowden extruder, direct drive, bearing bloc, auto load 1.75mm filament by scarou, http://www.thingiverse.com/thing:669459 . I used his design for a long time with my bowden setup but I was having problems with my stepper motor "thumping" during fast extruder moves. Also, I was having the usual "ringing" and "moire" on my prints. Of course this wasn't caused by his model. So I ordered a Bulldog XL clone from Robotdigg and found their extruder lacking in