Monoprice Mini X Axis Idler End Block by saabotage900

Last crawled date: 3 years, 1 month ago

This is a Prusa Mini-inspired MP Mini X-end idler block. It significantly improves the stability and alignment of the X axis, by clamping down on the rods as opposed to just using friction fit that's pressed on. My first layer calibration improved dramatically after using this mount, where it maintained Z stability across the entire length of the X axis. This is also much easier to install compared to friction fit. Before, forcing friction fit blocks on sometimes resulted in crooked axis, off-center Z axis, and inconsistency as the parts fatigued.
It contains two parts, the idler mount, and the X end block that houses the idler mount. My MP Mini also had a mis-drilled X end idler retainer, which resulted in a crooked belt. This idler retainer helps keep the idler straight, and the holes are centered so the belt doesn't ride one side.
Work in progress. Testing so far, no durability issues or fatigue when using PETG. Feedback welcome.
You'll need 3 M3 nuts (2 for the block, 1 for the idler) and a variety of M3 screws. Two M3 screws clamp the end onto the X axis rods, and another M3 screw acts as the pin for the pulley. Highly recommend a metal GT2 16T smooth pulley with bearings, as the screw will cut and wear grooves into the shaft of the stock plastic idler pulley.
Not designed to work with the stock X axis shroud.
Use PETG if you can, it's stronger and has just the right amount of flex. Otherwise, I believe PLA should work. 20-ish% infill, and 2 or 3 walls is sufficient for strength. Orient the parts flat side down for support-free printing. Dimensions are quite tight; the holes were designed at 6.1mm in diameter to let the rods slip in, then get clamped down. If you have to force the rods in the holes, then your printer's tolerances may need tuning and/or the rod entry points may need cleanup.