RepRapPro style extruder drive for RepRap Morgan.
For instructions, see here: http://reprappro.com/documentation/RepRapPro_mini_extruder_drive_printing
except that M4 20mm bolt is used, 624 bearings, and a M4 tapped 10mm OD 10mm long drive gear.
The 6mm Bowden cable clip fits on the foot of the extruder, and holds a M6 nut on the bowden cable.