velleman vertex k8400 settable Z axis stabilizer

I've tried different z-axis stabilizers form my Velleman K8400 Vertex 3d printer, unfortunately they don't fit to my printer due to the different gap from the back wall and the Z axis. So I've decided to design my own wit a settable distance. Te gap from the back wall and the Z axis center can be set from 22 to 25mm.
Once printed you need 2x M4x40mm screws, 2x M4 self locking nuts and a 608ZZ ball bearing.
Mount as showed in the picture, eventually put some adhesive tape around the ball bearin