MK6 Stepstruder cooling mod for PLA

I was having problems printing PLA with my TOM, after a period of time the heat would conduct through the stainless steel pipe and melt the PLA near the drive gear (causing it to bind up and stop extruding).

I tried to solve the problem by adding some heat sinks made from coins with an 8mm hole in the centre but on long prints (2+ hours) the PLA was still melting.

I had a 40mm fan lying around so I redesigned the back part of the acrylic Stepstruder support to accomodate a fan that blows