40x40x20mm version of Solidoodle Fan Mount and Duct for mk3 extruder

just made a quick change to be able to put a 40x40 mm fan in :)

how to controle the fan by gcode and the needed hack on your solidoodle can be found here:
http://solidoodletips.wordpress.com/2012/10/26/gcode-controlled-extruder-fan/