About this 3D model

Work in progress for a fan duct for my Prusa i3 Takes a 60mm fan. to replace the duct for http://www.thingiverse.com/thing:119616 modelled after http://www.thingiverse.com/thing:91931 but much more poorly designed. ;) Update: Channel to direct more air around the back of the fan. Better Default size for the stl More parameters for the scad. vent supports to reduce sag from heat