My printer has an upgraded block, and this is about 1-3mm to big for the block to go through. I imported into 123D design and changed the hole size to 18mm diameter. Ive tried to put the parts in the same location for the fan part. Not 100% but will see how goes. Ive also taken about 1mm of the part that goes into the fan as mine for some reason is just a bit smaller. Hope this helps someone else.
Ive just added edit_1 which has angled parts at the top like the original for for filament to stick to as the 1st part was ok but wasn't sticking properly.