5020 Cooling Fan for EVA 3

This was inspired by Biny's design (https://www.printables.com/model/294705-eva-3-cooling-inlet-for-5020-fan), but I created it using the original EVA 3 files. I liked the idea of a 5020 blower but wanted something less bulky and easier to print.

In order to do that, I had to modify the coreXY_back piece with additional mounting holes. You will not be able to use this with your existing carriage. I know this isn't convenient… but if you want convenience, use the design from biny! The two additional holes use the same heat inserts as the rest of the carriage; the hole geometry is the same. The fan is held in with a single 25mm M3 screw and M3 nut (I don't know why I used a nut instead of a heat insert).

The fan is held securely, but can flip up and away from the duct to allow easy access for cleaning.

There's also a variant with a bar designed to hit your Y endstop switch. I didn't like how the duct pressed the switch at an angle, and I had an issue with the switch itself sticking out too far into the build area, causing the gantry to collide with the front of the machine sometimes. That bar gives some breathing room to tweak the endstop position correctly. Just make sure to slide your switch over to the correct spot (If your endstop wires are facing DOWN, print it normally and slide your switch to the left. If your endstop wires are facing UP, mirror 5020_inlet_endstop in your slicer and slide the switch to the right).