Prusa MK4/MK3.9 y-rod-holder with thicker/stronger top

prusaprinters

Prusa's original y-rod-holder has a very thin section above the y-rod, which is prone to breaking if over-tightened.  Furthermore, if printed in ABS, the top may show unsightly stress marks after tightening, even if it is not over-tightened.This model increases the thickness over the top of the y-rod to increase its strength, such that it doesn't show stress marks even when tightened more than necessary.Some of the images show the extra ‘meat’ in red.  Nothing else has been changed with respect to the original part.Two STLs are provided - one is 0.875mm thicker than the original part (which doubles the original thickness), and the other adds a further 0.5mm, making 1.375mm extra.  Both fit comfortably beneath the y-carriage, the former leaving a clearance gap of ~1mm, the latter leaving about 0.5mm, as measured by calibrated MK1 eyeball :-)I have personally settled on the thicker of the two STLs for my machines.Thanks to user Hello for confirming that these models will also work with a MK3S and a MK3S+.For completeness I've included the OpenSCAD script that I used to generate these parts, as well as Prusa's original part that is required by the script.  The script should be self-explanatory.Print SettingsI printed all my MK4/MK3.9 parts for strength, so I started with the 0.2mm STRUCTURAL preset, then added 4 perimeters, 5 top and bottom layers, and 40% cubic infill.