In order to use a UM2 printhead on a Ultimaker Original+ (UMO+), the top part of the printhead needs to be rotated 90 degrees. I designed a dual extruder version, based on the original part (see github, UM2, step files). Also included is a modified bottom part, which enables to use a thicker fan (10mm) and still guide cables through the printhead. I used a Sunon MC25100V2-000U-A99 fan which has a good airflow while being very silent. Works like a charm, see video https://youtu.be/MSw4hv99LAA