Parametric linear bushing with low-friction (POM/delrin/nylon) filament inserts

This is a customizable (OpenSCAD code provided) linear bushing in which the low-friction interface is given by inserts of low friction filament. The sliding interface is composed of four filament sections spiralized 90 degrees in order to provide 4-point support and avoiding uneven wear of the rods. The body of the bushing can be printed on any material; I've been using PLA for the body and POM for the sliding interface with great success.

Previously, I've tested with 1.75 mm POM filament ins