This is a fan holder for a 50mm x 50mm x 11mm fan.
It was inspired by this thing: thingiverse.com/thing:8183
I made it because I could not find the right current setting for my stepper driver to keep the motors cool, and not lose steps.
I've added a butchered heatsink to improve the cooling capacity.
Now my X stepper stays cool, and doesn't mis a step!
As an added bonus, there's a hole for the wires.
The Y heatsink doesn't need a fan because it's bigger.
It's held in place by a suitably edited large paperclip.