Ender 3 X-rail Idler

thingiverse

The idler bearing kit for the Ender 3 X rail on the stepper side requires just two additional components: qty 2 6x10x3mm bearings. Once these are installed, the bearing cap is secured in place with a spot weld. The mount slides snugly into the right side of the X rail, where it mates with the dovetail groove on the front face of the rail. This configuration prevents the drive belt's teeth from rubbing against the aluminum extrusion, thereby eliminating unusual vertical patterns that can appear during printing. My own print was made in PLA, but ABS and other materials should also be suitable for this application. I chose to use 100% infill, but given the low stress nature of this component, a lower infill percentage would likely work just as well.