Ender 3 X-Axis motor side idler

thingiverse

I wanted to improve upon the original design I remixed (sorry) while keeping the stock X endstop cover intact. To do this, I used two small 10mm OD ball bearings with 3mm shafts (3x10x4mm). The shaft is 3mm in diameter and 17mm long. The through hole is blind on one side, but it's visible. Two bearings and some spacers between them are 8.4mm wide. I figured that since the assembly sits pretty close to the pulley, a flange isn't necessary. To make this design work, you'll need to shave off about 1mm of plastic cover support leg - one under the endstop (check the pictures). If you don't have the same bearings I used, I've attached an STL with a roller. The goal here is to move the belt away from the X profile so that its lower half doesn't grind and twist in the channel on the left side of the carriage.