I have a feeling the K8400 can do much better in this department without going E3D.
I printed and mounted this excellent design. http://www.thingiverse.com/thing:1213663Did not see the improvement I wanted I’m afraid. Super simple clip on design, very clever.
Any tips anybody like to share?
I printed it too, but it doesnt solve the real problem, that you have a single fan control for doing 2 very different things (cooling print and cooling print head isolator). If you increase fan speed too much, the nozzle will overcool. And when printing ABS, you cant avoid getting too much air blowing on the print if you want to prevent the isolator from overheating.
Having a 40mm fan blow horizontally on the isolator at a constant speed, and a gcode controllable fan cooling only the print, with a duct like the one you linked, would be far better IMO. Its not like its a novel idea, every printer I ever saw does it like this, including the K8200.