gripstruder 4x the grip force, in many cases this means extruding prints at over 800mm/m of 1.75mm feedstock

this is to be called the 'gripstruder' for its exceptional griping of feedstock.
12/1/2014:
recent addition of file xt5.stl , that has support that needs cut away, it deals with prolong use fatigue, and unifies lever pulley arm. best if level arm that holds bearings is made of ABS. other parts PLA is ok, just so much stress load is on arm that head cycles from motor heat tend to wear the original part out, abs is more graceful. part hinge is bolt of motor, and other parts are not under stres