MakerBot Print is our newest print-prepration software, which supports native CAD files and STL assemblies,
allows you to interact with all your printers via the Cloud, and many other exciting new features.
I have the same issue as @wdrake3. I tried two brands of 5015 fans, both don't fit the single fan version of the duct in the same way. I measured my fans and verified that they are 15mm not 15.8mm.
I guess I'll just jump to a dual fan solution since I now have two fans lol, hopefully that will fit properly for me.