Prusa i3 x-axis Idler with Tensioner

thingiverse

After upgrading my Prusa i3 rework from eMotion-Tech, I pinpointed a weak link: the x-axis idler block was a serious liability, and the entire printer urgently needed an easy way to fine-tune belt tension. Instead of the original setup's two salvaged hard drive bearings, I repurposed them as bearing mounts for a clever custom idler. I trimmed a 5mm pin down to snugly fit into its pocket, and discovered that a 5mm bolt would perfectly fill the bearing pocket before extending outwards through an outer block where it securely lodged against a nut. This design is so straightforward that swapping it in won't even require modifying the belt in any way. Notably, since I'm relying on mechanical endstops, there's no provision for optical endstops like those used in the part this replacement idler serves.