When using a front-mounted PLA fan with the Wanhao Duplicator 4S 3D printer, there is a chance that it will hit the door covering the front of the machine.
Here is a frame that will offset the door by 20mm and allow for a fan to be mounted on the front of the extruder carriage.
This thing is to keep the door open Wanhao Duplicator Printer 4 (or above).
This tool is used for leveling dual head nozzles on a Duplicator 4.
Modified version of http://www.thingiverse.com/thing:23013.
Hole center M3 = 75mm, head height =25mm
Added tap in center for preventing head from rotating when adjusting nozzle, worked very well.
Modified version of Duplicator 4 drive block to better enclose the drive wheel included for NinjaFlex filament.