Prusa i3 B MK8 duct V1

My first thingie for the Prusa i3 B Geetech MK8 extruder. It's a work in progress. It doesn't need an additional fan, just seal with a piece of paper the other side of the heatsink in order to increase air flow out of the fins on the eternal part of the heatsink and down the duct. The fins of the heatsink need to be mounted horizontally, not vertically. This apparently is the latest MK8 model with a plastic feeder (not aluminum).