Prusa Mendel i3 Rework extruder

Vertical direct extruder for 1.75mm filament(for 3mm just use drill bit).

Changes:
- Idler clamp is M4 bolt (length is depend from spring length), bigger hole for nut and bolt
- supports is already made (idler and fan)
- groove for motor mounting screws

All parts for build it together is compatible with this -> http://www.ebay.com/itm/Greg-Wade-Reloaded-Extruder-3D-Printer-Screws-Bearings-Springs-Hobbed-Bolts-/161674059456 kit