Replicator 2X active cooling fan duct - front discharge

This is an active cooling fan solution for the Replicator 2X. It is similar to the design by ten13th except it is made to work with any 40mm front-discharge fan. It is secured in place with two of the long hex bolts from the extruder, and the fan is secured to the duct using the bottom 2 screws.

I tried initially to use the MakerBot motherboard's cooling fan relay, however this is a 24V output so it should only be used with 40mm cooling fans rated for 24V. The relay did not seem to respond we