Ender-3 replacement Z-nut

thingiverse

I made a major update to this fix: I added pictures and an adapter STL and a keeper STL that holds the nut in place. I also included a screenshot of my settings, but there are two things not shown - the flow (93) and I add a line to the start G-code that calibrates E steps. That line is M92 E103.41 (this line should be adjusted so that printing G-code G1 E100 F100 extrudes 100mm; the default is E93, so if yours does less, you add to E93 and if it's over, use less than E93). I've found a setting of E103.41 works for me, but you'll have to find what works for you by printing G-code G1 E100 F100 at temperature and measuring from a sharpie mark on the filament to see how much it is unrolling exactly. You can always print and sand it to fit if your settings are off. The nut sits in the adapter, and the keeper holds it in place. The adapter has holes in the right spot to match up with the printer and the original screws. The most difficult part is that the nut is too big and round to fit against the stepper motor for Y access. To fix this, you need to grind a flat side on the nut to match the flat side on the adapter. It grinds fairly easily because it's brass; I used a piece of the Allen wrench as a pin just stick anything in the hole to keep it from spinning. Update: I added one 3% larger overall but kept the mounting holes the same. This worked on my uncalibrated Ender 3, now that I confirmed it fits, I ordered http://a.co/d/iYYT25B; it's a 5-pack in brass for $9.99 prime and I'll have to drill new mounting holes, but otherwise, I think that should work. My new Ender-3 arrived today, and the nut for the Z lead screw rod is missing threads as if it was not tapped. It should be T8 trapezoidal threads with 2mm pitch; if that's true, this should work (amusing my first try at Fusion 360 was done correctly). I'm going to print this as soon as I get to a working printer and update as needed. I made two versions: one is a copy of the original brass one as an STL, and the other is a solid block in the shape of the flange from the first one. I feel the solid one is better suited for 3D printing. The main 8mm hole is threaded with T8 trapezoidal threads with 2mm pitch, and I left the two small mounting screw holes unthreaded. It's based on the GitHub link: https://github.com/Creality3DPrinting/Ender-3, but that one was... wait for it... modeled without threads LOL! You can't make that up.