[quote=“svdv”]I had quite a lot backlash in the bronze tube bearings. Firstly I replaced the (shorter) top bearing for a bottom bearing, which is longer.
Secondly I replaced the rods. This was because I made my Vertex larger so I had to have longer rods. Fortunately this new rods were slighly thicker than the old ones and so, as a side effect, the bearings fitted precisely around the rods. I don’t have any backlash in the printhead anymore.
The only rattle I still hear is the radial fan on top when the head moves fast in x-direction. I once replaced that one also and that helped a little, but if anyone found a radial fan without the axis backlash, thus silent, I would like to hear…[/quote]
well maybe i should try to change the rods to new ones that maybe have higher quality, and change to new original bearings.
i´ve seen your xl build. pretty sweet upgrade, i wanna do that too. but its expensive to get stuff lasercut 
i hear no sound at all from my radial fan. but then again i have tonnes of noices from the bearings. so that may be why i dont hear it.