I'm fairly new around here, just finished the build and bed level + a few prints on a £150 from eBay Prusa i3 build. Plywood frame, M8 extruder assembly, GT2560 GEEETECH board, running Marlin v1.0.0 with some possibly different configs. The end stop switches are on different ports than the GEEETECH documentation suggests. Calls itself a CTC, but don't know if this is actually by CTC, can't see it on their website.

I know I will need to re-flash the Marlin firmware, probably just use a more up to date version with appropriate edits taken from what info I can derive from the current firmware. Step resolution, that sort of thing. I know that the wiring up needs a voltage divider so it doesn't fry stuff. I just have no idea how to physically plug the blasted thing in. I believe that I replace the Z-min switch with this, but that only accounts for two wires. Where do I pull power from or have I got the wrong end of the stick?

I think I know what needs changing in the Marlin firmware, it's pretty well documented from what I have seen. Are there any caveats I need to look out for?

As for mounting, I want to add in fan cooling. With the M8 extruder assembly, has anyone put together a unified Z-probe and a mount for a (preferrably) 60mm fan and toroid-esque cooler? I plan on hooking into the PWM fan slot for this, so I can control cooling properly. I'm getting my head around design and such, but not quite there yet.