https://www.partsbuilt.com/uptown-board-upgrade/ The new Partsbuilt.com board will let you easily power a fan for cooling your extruder heatsink. I purchase 40 mm square heatsinks from Amazon and glue to the extruder with heatsink plaster from eBay. I then use 3 mmx16 self tapping screws to attach a 30 mm square fan. The board has two new connectors: a 12v fan connector for use with the same type 12v fans on the shroud and a 5v connector for 5v fans. The board also has a resetable fuse that protects all of the fans on the print head. If you have ever replaced a fan and shorted the 12v you know that it needs the protection. The 12v supply on the Robo system board is fragile.