Idler Pulley for Ender 3 single motor dual z axis

thingiverse

Made a self-contained idler pulley for the single motor, dual Z-rod mod. Features a spring housed inside the block and relies on a 688zz ball bearing for smooth operation, secured in place by two M4 x 35 machine screws and two M4 T-Nuts that mount it to the frame. This design is currently a work-in-progress and could benefit from refinement of the sliding components. Originally, I envisioned using a rubber band hooked onto indents on each side, running through a slot on the inside portion of the axle piece for added tension on the belt. If a stronger application is required, this modification can be implemented. It's worth noting that when printing the pulley, it was necessary to reduce its size to 95% due to press fit issues; your specific printer may require adjustments.