Hi, after wearing out my second set of these ‘ilugur’ linear bearings, I decided to swap them with metal linear bearings type LM8UU. You buy them at several places like here:
Problem is that the plastic ildugur bearings are 1mm longer and 1mm bigger diameter, so you will have a lot of play if you install them just like that (and you don’t want that).
So you need an adapter to accommodate the LM8UU bearings into the ‘XY guiding blocks’. Printing them is of course the method of choice 
. However printing a cylinder with spot-on inner and outer dimensions is a bit challenging, especially when the cylinder wall is just a single perimeter 0.5mm. So to save the the hassle: here is the G-code file for printing the adapter in PLA on your Vertex: G-code file bearing adapter . It’s created with slic3r using the ‘spiral vase’ function so there’s no seem.
After 20hrs of printing I can only conclude the modification is successful. But one must take care of good alignment, because the metal bearings are less forgiving than plastic bearings and can cause lockup when not aligned.
Before attempting this modification, make sure you got belt-tension and alignment in order. See my older post: setting belt tension and alignment
succes!