Taken from:
Looks like more people are playing with single-nozzle water cooling. 
Are any of your 3D printers using water-cooled extruders? Just curious man.
Still haven’t gotten around to hooking up the Kraken, though I have everything for it. 
Ya that quad,water-cooled Kraken is insane! Would love to see it working on a Rostock style printer in real life…nobody in Toronto has built it as far as I know.
Danger , DANGER Will robinson !
@Tim_Elmore Thanks for the vid link - ended up hearing he’s going to use this x3Pro as his controller - http://www.panucatt.com/Azteeg_X3_Pro_p/ax3pro.htm
Good to know…(now on to search more vids!) - cool
Water cooled hotends with single nozzle.
Tri-colour -
http://deltaprinter.co.za/tri-colour/index.html
Single colour - http://deltaprinter.co.za/hotend/water-cooled-hotend.html
Dual -
http://deltaprinter.co.za/multi-colour-hotend/multi-color-hotend.html
@Peter van der Walt - dankie vir verwysing
With the original photo, I think there’s plenty more barrel shortening that could be done without compromising the design.