This is an adaptation of Replicator Ducted Fans Clip-on to (a) cool Print and PLA Replicator Ducted Fan Clips Modded to incorporate an idea from 40mm Fan Duct - Replicator 2X This is for a Makerbot Replicator 1.

The basic idea is to use the print head cooling fan as a print cooler as well. By using some ducting and reversing the orientation of the print head cooling fan, the exhaust can be used to cool the print.

In this design there is no need to removed the duct when print cooling is not required - just rotate the selector so that air is exhausted out of the top instead of on the print. This has the added benefit of directing exhaust air upwards out of the printer and can reduce drafts that may affect your ABS prints.

This thing was made with Tinkercad. Edit it online https://www.tinkercad.com/things/02jNZQIxTDJ

If your slicer can manipulate components from a single STL file then just download the first file, other wise you will need to download the duct and selector files.

Print out in ABS if possible. The duct is quite close to the print head and will go soft if it is PLA. Print them with 2 shells and 100% infill. No support is necessary.

You will need to replace the fan spacers with shorter ones to allow the original bolts to still fit. Use the ones here which are from Replicator Ducted Fans Clip-on to (a) cool Print. Don't forget to reverse the orientation of the fan.