I've created an improved version of this mount that includes ducts to direct the airflow for better cooling.
A dual cooling fan mount for the Robo 3D R1 that moves the fans back out of the way when using a larger hotend. I built this to work with my E3D v5, but there's plenty of clearance so it should work pretty much regardless of what hotend you're running.
This mount is based off of a fan mount designed by Tesseract which served me well for a long time before I decided to upgrade to a dual fan system. I modeled this one from scratch, but the design borrows heavily from Tesseract's original idea.
The mount is designed to work with 40mm or 50mm fans.
The fan mount screws into the right side of the carriage using the two existing holes there. You can either use 3mm screws (that's the way I had Tesseract's mount installed) or if you manage to strip the holes out like I did, you can tap for a #6-32 machine screw which seems to be working perfectly for me.