My current idea is to find a square plastic tube 2.25" ID and cut the length to match my ESC. Bolt the fan to the top, Shoe Goo the ESC to the inside of the tube, and then Shoe Goo the whole thing to my ESC plate. It's a bit more complicated than that but that's the basic idea. Finding a plastic square tube seems to be an issue, a pill bottle would work if it were the right size.