A simple mod to help stabilize the z-axis of the Velleman Vertex K8400. It uses a plain 608 bearing to hold the axis in place. I do have to say, for me the quality difference is barely noticeable but there's no vibrating sound coming from my z-axis anymore and I like that too. Before using the mod, please check if this mod fit's your printer too and that it doesn't damage your z-axis!