Creality Ender 3 Z-screw adjustable support (thin backplate) with shim & T-nuts

thingiverse

There's a lot of debate about the use of a Z-screw (or "rod") support on a Creality Ender3. My opinion is that it depends a lot on how things are done, as for everything in this world. Where are the benefits, and where are the problems? Due to the work I do for living, I deal with bearings of various kind all day, every day. Most bearings would benefit from an additional support, and in this case to add a mass (the rod) that cantilevers on the main bearing (here, the threaded nut that moves the Z-axis) is not perfect and if you can stop that mass from wobbling, it's all gravy. BUT any support has to be perfectly inline with the bearing, unless you want the bearing, or its supports, to malfunction and possibly fail. And this is where most designs fall short: they are not adjustable. Now, we assume that your Z-screw is very straight and starts aligned with the stepped motor, plus it keeps running inline with the Z-axis gantry. You want to see less than 1/2mm deflection when the Z-screw spins. If you get this,then you can use an additional support. My design is made with a thin backplate, and a 1mm shim is provided, so that you can adjust the distance between the support and the gantry, to have a perfect fit with your machine. If you need to shim for less than 1mm, I'd suggest to use thin M5 washers that will be more consistent than a very thin 3d printed single layer. The bearing to be used is 608 (8x22x7), you better use a "608-ZZ" or not shielded type (avoid the "608-2RS") to minimize friction. If all you have is a 608-2RS I'd suggest to remove the rubber seals. Two T-nuts are provided, you can use them with suitable self-tapping screws, print them with >50% infill and do not overtighten.