Automatic Cooling for Wanhoe Duplicator 4

I’ve been testing this automatic fan upgrade for my Duplicator 4 and WOW what an improvement in the quality of life around here. Finally I can just start a print on my Dup 4 and walk away knowing the active cooling fan will start on its own. No more being a slave to the printer. It goes in series with my existing fan circuit and bolts on using hardware already there. It is micro adjustable so you can set it to turn on after a set distance into the print, up to about 5mm or even more if you use a