Ender 3 Pro filament sensor (aka Z endstop) holder

thingiverse

UPDATE: July 22, 2020: I moved the filament path down by 1mm to better line up with the switch and the extruder inlet. Also added a couple cutouts on the outside to accommodate a zip tie to hold the wiring in place. I found several versions and remixes for reusing your old Z axis endstop as a filament runout sensor, but none seemed to fit the endstop from the Ender 3 **PRO**. Well, now one does <del>(**Hopefully.** I have printed it, mounted the endstop, and tested with a little chunk of filament to hear the *click* of the switch, and it appears to work. Will update after I get it put on the machine and plugged in to OctoPi.</del> **UPDATE**: Have had the sensor mounted, plugged in and running (using Filament Sensor Revolutions) for a few weeks now and works as expected.) The problem seems to be that the Ender 3 Pro's endstops are just a hair longer (the board), and the switch itself sticks out from the board just a hair more, so either the switch would sit on top of the cutout for the arm (and then wouldn't release after the filament ran out), or, if placed so the switch wasn't sitting on the shelf, the mounting holes didn't line up (the switch still didn't work properly, and you couldn't bolt it in place). This fixes both problems. After completely redrawing it in FreeCAD, because FreeCAD didn't like the .stl mesh for some reason, I added an extra cutout so the switch body wouldn't hit the "shelf" where the filament runs through, and the switch arm could actually open after the filament was pulled through. I also deepened the cutout where the board connector plugs in, so it actually clears. Side note: pictures on the original thing(s) show "1845" on the endstop PCB, where mine says "1929". I'm assuming this is a model number, or something similiar. I Googled it to see if I could find any info/schematics/diagrams, but gave up after about 10 minutes because Google gave nothing but purchase links. Also, while trying to fit one of the other prints, I bored out the PCB holes with a #30 drill bit. Don't know if it made any appreciable difference, but there it is.