Rigidbot single head cooling fan mount

NOTICE: See http://www.thingiverse.com/thing:1381040 for the Rev-2 revision of this design if you have had issues with the mounting tab breaking. Modifications include a wider tab and a strength rib along the edge.

A single fan mount for a stock Rigidbot. The duct blows on the nozzle tip to avoid heater block temperature fluctuations. Requires no additional hardware to mount the duct. Clears the bed by 2 mm and does not touch the rails.

This is simply a modification of my dual head mou