

Just an idea I have since a long time, I could not find time to test it. The idea is to let warm air around the heatbreak/block go out easily from the bottom of the extruder. This could improve part cooling and stringing.
Another possibility that is not represented here is to use the flow going out of the heatsink to suck the air from this hole. This would create an active flow compared to a "chimney effect".
STL attached for those that would like to make some testing. This is exclusively for extruder currently in dev (MK2.5S and MK3S).