RepRapPro Ormerod dual fan duct

Fan duct for RepRapPro Ormerod using dual fans. One cools the hotend heatsink, the other cools the print. The advantage is you can completely disable the "print cooling" for example when printing ABS, and have software-controlled fan speed while still maintaining hotend cooling. As the hotend can be kept cool with quite low airflow, that fan can be slow and silent.
This design uses a 5010 50mm 12V radial blower, that can just be glued to the fan duct (I used plain CA glue). The original hotend